Emergency Department Visits for Pediatric Poisoning in China: A 318-Case Review

Introduction

According to the World Health Organization (WHO), poisoning refers to injury caused by exposure to an exogenous substance that causes cell damage or death, either by inhalation, ingestion, injection, or skin absorption [1]. A report released by the WHO in 2008 showed that poisoning is among the top 5 causes of death from unintentional injuries among children worldwide [1]. In the United States, drug overdoses or poisonings were the sixth leading cause of death among children and adolescents in 2016 and became the third leading cause in 2020 [2,3]. According to data released by the National Health Commission of the People’s Republic of China, the category “injuries and poisoning” ranked fifth among causes of death in China between 2005 and 2021 [4]. The Ministry of Health of China established the National Poison Control Center in 1999 to provide information concerning poisoning prevention and help with poison emergencies. Provincial- and national-level chemical poisoning treatment bases have been established throughout the country [5].

Poisoning in children is characterized by regional differences, and the characteristics of poisoning in children may change with the passing of time [6,7]. It can also be impacted by socioeconomic and cultural factors. Statistics show that drugs and pesticides are the main substances involved in poisoning of children in China, among which drug poisoning is dominant in cities, while pesticide poisoning is common in rural areas [8]. Rural residents generally have poor safety awareness. Zhang et al [9] reported that 63.9% of rural residents stored pesticides in a location easily accessible by all household members. Therefore, the incidence of pesticide poisoning in rural areas is higher than in urban areas [8,10]. In Western countries, drugs and household products are common causes of poisoning in children [6], and cases of poisoning by alcohol and illegal drugs are reported occasionally [11]. However, alcohol and illegal drugs are not mentioned in the research papers involving causes of poisoning in children in China [7,8,12], possibly because there is a strict monitoring system for illegal drugs in China [13], family members concealing poisoning caused by alcohol or illegal drugs, and data reporting biases. The types of poisons are also different in the cities, which are adjacent to each other in China. For example, a study conducted in Chongqing, China has shown that pesticides and rat poison were commonly used in intentional poisoning [8], whereas our study found that intentional poisoning cases in Chengdu (a city near Chongqing) were commonly caused by medications. Urban residents generally face greater academic stress and may have more obvious mental health problems, so they are at higher risk of intentional poisoning [8]. These findings suggest that an in-depth study of regional poisoning is important for developing targeted prevention and treatment strategies.

This study was conducted in our hospital. Our hospital is located in Chengdu, the largest city in southwest China. Many patients visit the Emergency Department (ED) of our hospital every year. Patient data from our ED is representative. There have been no studies on the characteristics of poisoning in children in Chengdu, especially on the epidemiological characteristics of poisoning after the COVID-19 pandemic. Other scholars have investigated the characteristics of pediatric poisoning cases in different regions of China, but most were conducted based on national or province-specific data. The characteristics of pediatric poisoning cases in Chengdu receive less attention. Urbanization, socioeconomic changes, and changes in medication use after the COVID-19 pandemic may have significant impacts on the characteristics of poisoning in children in Chengdu, so it is necessary to conduct research on the characteristics of pediatric poisoning cases in Chengdu.

This study revolved around the following questions: (1) Are the epidemiological characteristics of poisoning in children in Chengdu consistent with global or other regional trends? (2) Are there significant differences in the incidence of poisoning in children by age, gender, and season? (3) What percentage of pediatric poisoning cases in Chengdu are caused by medications, and how does this compare to other regions? (4) Are there significant differences in types of poisons and causes of poisoning among teens? (5) What substances can cause teens to be more susceptible to poisoning? (6) In our study, only 35 patients (11%) received first aid treatment from their family members to remove poisons before visiting our ED, which is lower than the 18.7% reported by Bacha et al [14] in Ethiopia. Are there deficiencies in the knowledge and response capacity of family members and the society in pre-hospital emergency care for poisoned children in Chengdu? Based on these questions, we conducted a retrospective analysis of the clinical data of 318 poisoned children who visited the ED of our hospital in 2023. The epidemiological characteristics of poisoning in children, including causes of poisoning, types of poisons, incidences of poisoning in different age groups, seasonality, and disposition of patients, were analyzed in this study. Our study aimed to investigate the epidemiological characteristics and potential risk factors associated with poisoning in children in Chengdu, China. This can provide data on poisoning in children after the COVID-19 pandemic.

Material and Methods

ETHICS APPROVAL AND CONSENT TO PARTICIPATE:

This study was approved by the Medical Research Ethics Committee of West China Second University Hospital, Sichuan University (2023 Medical Scientific Research for Ethical Approval No. 390). Because this was a retrospective study based on patient information collected from the hospital information system, the requirement for written informed consent was waived upon the approval of the Medical Research Ethics Committee of West China Second University Hospital, Sichuan University. Data were de-identified during collection and storage. Access to the data was restricted to authorized members of the research team, who were trained to understand and fulfill their responsibilities in data protection.

SUBJECT OF STUDY:

This study was conducted based on patient data from our hospital. Our hospital is a women’s and children’s hospital and is the national children’s regional medical center (southwest) of China. Most patients of our hospital come from Sichuan, Guizhou, Tibet, and Shaanxi, having greater regional influence. Clinical data of pediatric patients who visited our ED during January 1 to December 31, 2023, were investigated in this study.

The inclusion criteria were as follows: (1) patients who had chief concerns of, “orally taken by mistake”, “poisoning” or “excessive”, or stated on diagnosis certificates; and (2) patients under 18 years of age. A total of 349 cases met the inclusion criteria. The exclusion criteria were as follows: (1) patients with incomplete clinical data; (2) patients with sepsis; (3) patients bitten or stung by a venomous insect; (4) patients with lead poisoning; or (5) patients who came back for a follow-up visit. A total of 31 cases were excluded from this study. Therefore, a total of 318 patients were included in this study. Among the 318 patients, 150 (47.2%) were male children, and 168 (52.8%) were female children. The youngest patient was 24 days old, and the oldest patient was 17 years old. The median age was 2.54 years (1.67–4.96). Demographic information of the 318 patients is presented in Table 1.

STUDY DESIGN:

The information concerning visits of the studied pediatric patients was extracted from the hospital information system. A retrospective epidemiological study was conducted. A form titled “Investigation Data Form for Poisoning in Children” was designed by referring to the International Classification of Diseases (ICD-10) and the characteristics of our hospital, to gather the following information: demographic information (gender and age), routes of poison entry (orally taken, or skin contact), substances that cause poisoning (types of poisons, and number of types of poisons), causes of poisoning (unintentional poisoning, or intentional poisoning), treatment before visiting our ED, disposition of patient, time of poisoning, season of poisoning, and symptoms of poisoning. The form was designed based on relevant literature and expert opinions to ensure its validity. Training on data collection was provided for data collection personnel. Ambiguities in the form were solved in the data collection process and data were cross-checked by data collection personnel to ensure data accuracy and consistency.

Poisons were divided into 3 categories: medications, harmful substances, and toxic substances (Table 2). Medications are substances with pharmacological activities and can be used to prevent, treat, or cure diseases. Harmful substances are substances that can cause poisoning under certain conditions but are not highly toxic. Toxic substances are substances that can cause symptoms of acute poisoning at relatively low doses. Adverse drug reactions, food poisoning, chronic poisoning, and carbon monoxide poisoning cases were excluded from the study. Our study focused on acute poisonings, so chronic poisoning and adverse drug reaction cases were excluded from the study. Chronic poisoning usually involves long-time exposure to low doses of poison, such as heavy metals and the accumulation of environmental pollutants, whereas adverse drug reactions may be associated with individual differences, dose-dependent effect, or allergic reactions. The mechanisms of occurrence and clinical management of these conditions are different from those of acute poisoning, so they were not included in the analysis to ensure data homogeneity and comparability. The causes, clinical management, and prevention measures for carbon monoxide poisoning are significantly different from those for other poisoning cases, so carbon monoxide poisoning cases were excluded from this study. Only 1 carbon monoxide poisoning case was found among all pediatric patients who visited our ED in 2023, and it was excluded from this study in the data screening process to ensure research focus. The exclusion had a limited impact on the study results.

The causes of poisoning were divided into 2 categories: (1) intentional poisoning, referring to intentional improper use of poison; (2) unintentional poisoning, referring to unintentional exposure to or administration of the wrong/excessive poison. The classification of the causes of poisoning was determined based on medical history statement, medical records, and doctor’s judgment. A poisoning case should be first evaluated independently by 2 professionals. The unanimous judgment was directly recorded as the final evaluation result. If there was disagreement, a third expert reviewed the case and organized a group discussion to obtain a decision from at least 2 clinical experts. If the cause still could not be clearly determined, the case was classified as unintentional poisoning to ensure consistency and reduce bias.

STATISTICAL ANALYSIS:

SPSS 23 was used for data analysis. The Shapiro-Wilk test was performed to determine whether the data were normally distributed. Quantitative data are presented with mean and standard deviation, while skewed data are expressed as medians (P25, P75) and enumeration data are expressed as the number of cases (percentage). The chi-square test and Fisher’s exact test were performed to analyze the distribution of patients with different clinical characteristics (eg, gender) among different types of poisons. Pairwise comparisons relied on chi-square test results combined with the α partition to improve the accuracy of the test and control the risk of false positives caused by multiple comparisons, thus accurately revealing significant differences between variables. Multivariate logistic regression modeling was used to analyze the independent effects of the significant variables and interpret the odds ratio (OR) and its 95% confidence interval (CI), thereby further revealing the strength of an association between influencing factors. A statistically significant difference was identified by P<0.05.

Results

TYPES OF POISONS AND ROUTES OF POISON ENTRY:

Among the 318 patients, 198 (62.3%) were poisoned by medications, 79 (24.8%) were poisoned by harmful substances, and 41 (12.9%) were poisoned by toxic substances. Regarding types of poisons, 36 (11.3%) were caused by psychotropic drugs, accounting for the highest percentage, and 34 (10.7%) were caused by cleaning products, among which toddlers accounted for the highest proportion, at 85.3% (29/34). Regarding routes of poison entry, 316 (99.4%) were oral, 1 (0.3%) was by skin contact, and 1 (0.3%) was by taking orally plus skin contact (Table 1).

TREATMENT BEFORE VISITING OUR EMERGENCY DEPARTMENT AND DISPOSITION OF PATIENTS:

Among the 318 cases, 35 (11%) received treatment from their family members before visiting our ED, 149 (46.9%) were admitted to the hospital, and 169 (53.1%) were advised to go home after visiting our ED. Of the 35 patients who received treatment from their family members before visiting our ED, 14 (40%) were admitted to the hospital (Table 1). The types of pre-hospital treatment from family members included the following. (1) Inducing vomiting. The family members of 20 poisoned children tried to remove poisons through inducing vomiting. (2) Dilution with fluid. Five poisoned children were asked to drink milk or water to dilute the poison. (3) Neutralization by adding an acid. One poisoned child was asked to take vinegar orally to remove poison. (4) Cleaning the oral cavity. Five poisoned children were asked to clean the oral cavity to remove poison residues. (5) Combined treatment. Two poisoned children were asked to drink milk or water after inducing vomiting, 1 poisoned child was asked to drink soapy water after inducing vomiting, and 1 poisoned child was helped with face cleansing after inducing vomiting.

GENDER AND AGE:

The 318 poisoned children (150 males and 168 females) accounted for 0.16% of the total number of pediatric patients that visited our ED during the entire year of 2023. Female children had a higher incidence rate of poisoning than male children (χ2=8.149; P=0.004). The incidence rates of poisoning were different in different age groups (χ2=449.296; P<0.001). No statistically significant differences were identified in the incidence rates of poisoning among infants (0 to <1 year), preschoolers (3 to <6 years), and school-aged children (6 to <12 years) (P>0.005). The incidence rates of poisoning in teens (≥12 years) and toddlers (1 to <3 years) were significantly higher than in other age groups (P<0.005) (Table 3).

SEASONS OF POISONING:

The incidence rate of poisoning was the highest during summer [120 (0.3%)], followed by spring [114 (0.2%)], winter [69 (0.1%)], and autumn [15 (0.03%)]. The incidence rates of poisoning in children were different during different seasons of the year (χ2=94.778; P<0.001). The incidence rates of poisoning in summer and spring were different, but the difference was not statistically significant (P>0.008). The incidence rates of poisoning in spring and summer were significantly higher than in autumn (P<0.008) and winter (P<0.008). The incidence rate of poisoning in autumn was significantly lower than in winter (P<0.008) (Table 4).

TYPES OF POISONS:

Among the 318 cases, 198 (62.3%) were poisoned by medications, followed by harmful substances in 79 cases (24.8%), and toxic substances in 41 cases (12.9%). A statistically significant difference was identified in the types of poisons between teens and non-teens (χ2=11.816, P=0.003). The incidence rate of medication poisoning in teens was significantly higher than in non-teens (72.2% versus 60.2%, P<0.017). The incidence rate of harmful substance poisoning in teens was significantly lower than in non-teens (7.4% versus 28.4%, P<0.017). The incidence rate of toxic substance poisoning in teens was significantly higher than in non-teens (20.4% versus 11.4%, P<0.017) (Table 5).

In this study, 298 (93.7%) patients were poisoned by a single substance, and 20 (6.29%) were poisoned by multiple substances. No statistically significant difference was identified in the number of types of poisons between males and females (χ2=0.44, P=0.507). However, teens had a significantly higher incidence of poisoning by multiple substances than non-teens (χ2=14.1, P<0.001). A statistically significant difference was identified in the incidence rates of poisoning by multiple substances between the children who were intentionally poisoned and those who were unintentionally poisoned (χ2=17.58, P<0.001). The hospitalization rate among children who were poisoned by multiple substances was significantly higher than among children who were poisoned by a single substance (χ2=6.181, P=0.013) (Table 6).

FACTORS ASSOCIATED WITH INTENTIONAL POISONING:

In this study, 274 (86.2%) were unintentionally poisoned, and 44 (13.8%) were intentionally poisoned. A single-factor analysis of the 44 intentional poisoning cases showed that females had a higher incidence of intentional poisoning than males. The incidence of intentional poisoning increased with age (infants 0%, toddlers 0%, preschoolers 0%, school-aged children 20%, and teens 74.1%) (P<0.001). Teens had the highest incidence of intentional poisoning, followed by school-aged children. Children with a history of mental illness had a higher incidence rate of intentional poisoning than children without a history of mental illness. The incidence rate of intentional poisoning by multiple substances was higher than that by a single substance. The incidence rates of intentional poisoning by medications (33 cases) and toxic substances (11 cases) were higher than harmful substances (0 cases) (Table 7). Multivariate analysis results showed that being a teenager and having a history of mental illness were independent risk factors for intentional poisoning (Table 8). The incidence rate of intentional poisoning in teens with a history of mental illness was 90% (18/20) and that in teens without a history of mental illness was 64.7% (22/34), with a statistically significant difference (χ2=4.195, P=0.041).

Discussion

Acute poisoning in children is commonly caused by medications [15]. This study found that medication poisoning accounted for 62.3% of acute poisoning in children. This was the highest proportion among all poisons in our study, and is higher than the emergency department data from 20 foreign countries, which showed that medication poisoning accounted for 42.7% of all acute poisoning in children [6]. Medicines are stored improperly by many families and can be easily accessed by children [16]. Traditional Chinese culture advocates that young and their elderly family members should live together. With increased population aging and life expectancy in China [17], grandparents or great-grandparents may participate in children’s development [18]. Elderly people generally need to take different medications due to chronic diseases, so medications may more common in a child’s living environment [19]. Previous studies have shown that access to toxic substances increases the risk of poisoning in children [15]. The high possibilities of access to medications in families with an elderly member may increase the risk of poisoning in children. In addition, previous studies have shown that grandparents acting as guardians of children is an important risk factor for poisoning in children [20]. In families with an elderly member, more attention should be paid to the storage of medications. Our study found that the oral route was the most common route of poison entry, accounting for 99.4% of the included cases. Young children are inquisitive and often put objects in their mouths as a way to explore the world. The medications in family medicine storage boxes are usually oral medications, and this might be why medications are accidentally ingested by children.

The medications causing poisoning in children in different countries and regions are different due to national conditions, social status, and ethnic differences. Among the 318 poisoned children in our study, the incidence of poisoning caused by psychotropic medications was the highest, which was similar to the results of other scholars [21]. However, studies conducted in the United States and the Czech Republic showed that painkillers were the most common medications causing poisoning [22–25]. The common characteristics of psychotropic medications and painkillers are that they are long-term or frequently-taken medications. Perveen et al [19] found that 69% of family members usually put long-term or frequently-taken medications in the living room, thereby making the medications easily reached and therefore unintentionally taken orally by children. Therefore, the effective supervision and proper storage of medications is particularly important [26].

In our study, household cleaning products were the second most common substances causing poisoning in children, which is similar to data from the United States (10.7%) and from Taiwan (9.2%) [23,27]. Among the children who ingested cleaning products by mistake, toddlers accounted for the highest proportion. Household cleaning products have become common poisons all over the world, partly because some family members use beverage containers to sub-package the household cleaning products for convenient use [6,28], thus increasing the intake risk for children. In addition, household cleaning products rarely use child-proof packaging. Family members generally do not think that household cleaning products are harmful to children [29], and they are often placed in low places for easy access [6], making it easy for children to find them. The harm caused by household cleaning product poisoning may be far greater than we think. Some cleaning products contain corrosive substances, and ingestion of a very small amount can cause severe esophageal burns [30], which is extremely dangerous and can cause long-term sequelae.

Previous studies have shown that poison prevention education can effectively improve medication awareness and poison prevention behaviors [31,32]. Families and society need to work to prevent poisoning in children caused by medicines and household cleaning products. The following society-level measures may be implemented: (1) Legislation. It is advised to legislate for the safe dose packaging of medications and pack them in non-lethal dosage for children, so as to reduce the risk of unintentional ingestion. (2) Popularization of education in safe use. The public health authority should popularize the education of safe use of medications and household cleaning products, and inform families with children of the potential harm and prevention measures. (3) Standardization of packaging. For example, it is important to use safe package for children and avoid using brightly colored packaged cleaning products or those similar to food packaging, to reduce the attractiveness of these substances to children. The following family-level measures may be implemented: (1) Proper storage. It is advised to avoid putting medications and cleaning products in places accessible to children. Family members should keep medications and cleaning products in a locked box or a high place to avoid exposure to children’s activity areas [19,32]. (2) Avoiding risks. For example, family members should avoid analogies of medications to candy, and not sub-package household cleaning products in confusing containers (such as beverage bottles) [19]. (3) As children get older, safety education should be provided. This can enable children to identify the usage and potential harm of medications and cleaning products. It is important to develop children’s habit of reading and following labels or instructions of medications and cleaning products. Through the dual intervention of social policies and family education, children’s ability to identify medications and chemical products can be comprehensively improved.

Potential challenges in the implementation of the preventive measures were also identified. These recommendations have been repeatedly mentioned in previous reports. Parents may have been aware of the proper storage methods for medications, harmful substances, and toxic substances, but not all parents implement it properly. A survey of 5088 people about storage of pesticides showed that 249 (4.9%) kept pesticides in locked storage, 1588 (31.2%) stored them in a high location not easily accessible to children, and 3251 (63.9%) stored them in a location easily accessible by all household members [9]. This suggests that cognitive development does not always trigger behavioral change. It may be difficult for low-income households to afford the cost of safe storage facilities due to financial constraints. In addition, traditional first aid measures (such as inducing vomiting or taking folk remedies orally to remove poisons) in some cultures may remain entrenched. This can hinder the popularization of first aid knowledge and skills. The United States and some European countries have forced the implementation of child-resistant packaging, but there are no relevant laws or policies in China [33]. Health education in China is usually a one-time information transmission, and fails to establish an effective long-term behavioral intervention mechanism. Continuous community health education can more effectively promote the improvement of medication management by family caregivers. The impact of a single lecture or publicity activity may be temporary and limited. Continuous educational activities can be organized to improve the transmission efficiency and acceptability of information concerning poisoning prevention, and flexible policies and legal frameworks can be developed to promote child safety. For example, multi-level promotion strategies should be formulated according to the economic level and cultures of different regions to promote the legislation on safe packaging for children. Due to limited economic conditions or low levels of health awareness in rural areas, it is often easier to carelessly store medications/toxic substances [34]. Knowledge of safe storage of medications/toxic substances should be popularized in rural areas. In cities, the use of products with safe packaging for children should be promoted widely and targeted education should be strengthened.

In our study, the rate of early treatment after poisoning was low and the treatment methods were inappropriate. Mintegi et al [11] found that the proportion of patients with clinical symptoms who were treated within 1 hour was significantly lower than patients who were treated later. Early and correct treatment for poisoning can slow the absorption of poisons. In our study, only 35 patients (11%) received first aid treatment from their family members to remove poisons before visiting our ED, similar to the results of Mintegi et al [11], who conducted a study in Spain, but lower than the 18.7% reported by Bacha et al [14] in Ethiopia. Medical resources in low-income countries such as Ethiopia may be scarce. Our study was conducted based on patient data from a tertiary Grade A women’s and children’s hospital in China, reflecting a population with relatively sufficient medical resources. However, a low rate of pre-hospital emergency care was found in our study. This shows that the popularization of first aid knowledge and skills is insufficient, rather than simply due to the limited medical resources. The differences in first aid implementation rates between China and Ethiopia may be due to cultural, educational, and systemic factors. In our study, some patients diluted the poisons or cleaned the oral cavity before visiting our ED. These pre-hospital first aid measures may be helpful in specific situations, but have limited scope of application. Dilution with fluid (drinking water or milk) can reduce mucosal irritation after ingestion of non-corrosive, water-soluble poisons. However, it is not suitable for other poisons, such as corrosive substances and surfactants, because it can aggravate the conditions. The treatment measures should be used with caution. Cleaning the oral cavity (gargling or wiping) is suitable for cases where there are poison residues in the mouth after oral administration of corrosive or irritating substances and can reduce local tissue damage. However, it is limited to poison residues in the oral cavity and has no obvious effect on swallowed poisons. The effectiveness of these pre-hospital treatments depends on the type of poison. Improper pre-hospital treatments can pose risks. In our study, improper pre-hospital treatment measures were found in some cases. For example, the family members of a pediatric patient who mistakenly took respiratory medications asked the child to drink soapy water after vomiting, which was wrong. Other treatments, such as taking vinegar or rinsed rice water orally, and inappropriately induced vomiting, are also incorrect. Vomiting can cause asphyxia and aspiration pneumonia. Inappropriate use of some substances (such as taking soapy water and rinsed rice water orally) can aggravate damage to the digestive system. These incorrect treatments can make the patient’s condition worse and lead to more serious health problems. It is particularly important to raise public awareness of proper first aid measures. The reasons for insufficient/incorrect treatment of children by family members may be as follows: (1) China’s poison network building is relatively undeveloped. The United States established its poison control center in 1957, and the poison network covered all 50 states in the United States in 2003. China started to build its poison network in 1999, and the poison network only covers national-and provincial-level healthcare institutions. Chinese people generally are uneducated about first aid for poisoning and the early treatment of poisoning. (2) The use of poison counseling hotlines is low. A survey conducted in a city in China showed that 49.6% of Chinese people were completely unaware of the poisoning counseling hotline [35], only 53.6% of poisoning treatment professionals knew the poisoning counseling hotline, and only 2.5% of people contacted the poisoning counseling hotline for help immediately when they had a need for a poisoning treatment counseling service [36]. China needs to strengthen poison first aid education and promote the poisoning counseling hotline. There may be some challenges in promoting these measures. For example, the public may have low levels of awareness of the function and importance of the hotline, especially in the study population, and education may be impossible in remote rural areas. These challenges can be overcome through education by primary healthcare institutions (such as community healthcare service centers and rural clinics). This can improve public awareness of the hotline and the ability to respond to poisoning emergencies. The medical emergency telephone number system can be connected to the poisoning counseling hotline, allowing callers contacting local medical emergency services for poisoning to be directly guided to call the poisoning counseling hotline.

Of the 318 poisoned children in our study, 35 (11%) received pre-hospital treatment. Among the children who received pre-hospital treatment, 14 (40%) needed hospitalization. This suggests that the implementation of first aid measures before the hospital visit can help reduce the hospital admission rate. Early treatment is associated with the disposition of patient. The following 2 factors can also affect patient disposition: (1) the types of poisons and amount ingested can affect treatment results; (2) the quality and appropriateness of first aid provided by family members. First aid mistakes can aggravate the patient’s condition. Therefore, we need to be cautious in interpreting the study results. Further research is needed on the types and quality of first aid measures provided by family members before hospital visits and on the impact on clinical outcomes.

In our study, most of the poisoned children were advised to go home after receiving treatment in our ED. However, there were no follow-up investigations on the pediatric patients who went home and no poison prevention education. This could affect the long-term health management of the poisoned children. In our study, 46.9% of the poisoned children needed hospitalization, and 53.1% of the poisoned children were advised to go home after receiving treatment in our ED. Most children in our study were young children who were unintentionally poisoned and were exposed to small amounts of poisons or poisons with mild toxicity, and most had no symptoms [11,23]. Therefore, most of them went home after treatment (such as gastric lavage) in our ED, and did not need hospitalization. In our study, we found that follow-up investigations were not conducted with the pediatric patients who went home, so it was impossible to know whether they developed symptoms or visited any other hospitals after returning home. Although previous studies have shown that gastric lavage is an effective treatment for poisoning in children, a follow-up investigation should be conducted with pediatric patients who received such treatment [14]. There was also a lack of records concerning poisoning prevention education in the medical record system. The studies of foreign scholars have found that there is a lack of appropriate education for emergency department patients to prevent future poisoning, while effective poisoning prevention education can reduce the incidence of secondary poisoning in children [37]. Poisoning management education for parents has not yet become a part of routine pediatric health education, possibly because there is limited policy and financial support of the medical system in this area. In addition, medical staff for pediatric health care engage in a large amount of diagnosis, treatment and nursing work, and their awareness, time and energy for poisoning management education may be relatively insufficient. A national study on poisoning management education to assess the role of medical staff in that field and parents’ knowledge demands will be a meaningful direction of research. Previous studies have shown that establishing poison control centers to provide poison prevention education and providing medication safety education for family caregivers are conducive to reducing the occurrence of poisoning in children [38,39].

Healthcare institutions in China should improve the prevention education and follow-up investigations for poisoning in children in emergency departments according to aforesaid success cases. Emergency department physicians can briefly explain the first aid steps for common poisoning to family members before the pediatric patient is discharged (such as poison removal and initial treatment), and provide the poisoning first aid manual or quick response code for family members to learn. A follow-up visit can be implemented in cooperation with primary healthcare institutions (such as community healthcare service centers) to follow up discharged patients, so as to evaluate the treatment effect and provide rehabilitation guidance. In addition, putting up first aid posters in hospitals and providing poisoning counseling hotlines can help the public understand the knowledge of first aid and emergency channels for help, to respond more effectively to poisoning in children.

In this study, there were more females than males poisoned, and teens and toddlers had higher incidence rates of poisoning than other age groups. This is possibly due to the change of social customs and gender and age differences. The poisoned pediatric patients accounted for 0.16% of all pediatric patients that visited our ED during the entire year of 2023, which was similar to the results of 0.2–0.3% reported by other scholars [30,40,41]. In our study, female children had a higher incidence of poisoning than male children, which was similar to the results found in Ethiopia and the Czech Republic [14,22]. However, males had higher incidence rates of poisoning than females in Taiwan and southwest China [8,30,42], possibly because Chinese families paid more attention to the health of boys and are more willing to give priority to the treatment of boys [8] due to the traditional Chinese custom of son preference. With the development of society and economy, the traditional Chinese custom of son preference has changed [43]. Nowadays, health of female children has attracted increasing attention from society and family members, making female children’s health data easier to find and record. The incidence rates of poisoning among males and females in China in the past usually reflected the number of poisoning cases that were recorded, not the actual number of poisoning cases. Therefore, past data showing that males had a higher incidence of poisoning than females in China may not reflect the current situation. Previous studies have shown that girls are more susceptible to social, family, and cultural influences, which can lead to greater exposure to poisons or their choice of poisons. Similar circumstances were also reported by scholars from other countries [44]. Girls are more likely to attempt suicide when they feel helpless and lonely and have conflicts with parents or peers, possibly because girls are more emotionally sensitive and have deeper perception of interpersonal conflicts [45,46]. Future research could investigate gender differences, particularly the impact of mental health support and social environment on teenage girls.

By analyzing the age of the poisoned children, it is found that the incidences of poisoning in teens and toddlers were different from that in other age groups. The incidence of poisoning in teens was the highest as the incidence of intentional poisoning in teens increased, followed by toddlers aged 1 to <3 years as the incidence of unintentional poisoning in toddlers increased. Similar findings were reported by Gummin et al and Wiener et al regarding poison centers in the United States [21,24,47]. Poisoning in toddlers is usually unintentional [21], possibly because toddlers have an expanded scope of exploration of the surrounding environment, and a strong desire to explore the world. They often perceive the outside world through their hands and mouths, while their perception of danger is weak [41]. Moreover, toddlers have limited cognition and are usually attracted by brightly colored objects, so it is easy for them to confuse medications with candy [48]. Furthermore, insufficient family supervision of toddlers may also be a factor associated with a higher incidence rate of poisoning in toddlers [49]. A high incidence of intentional poisoning in teens was identified in our study. Teenagers are not yet emotionally stable and mature, they can easily succumb to pressure or frustration in interpersonal relationships, and they may not balance family expectations in learning [8,50]. When conflicts or stimuli occur, they are prone to attempting suicide by self-poisoning [51], resulting in a high incidence rate of poisoning in this age group.

In our study, the incidence rate of poisoning was the highest during summer. Both spring and summer were the high seasons for children to be poisoned. Therefore, equal attention should be paid to prevention and control measures adopted in spring and summer. Studies on the correlations between poisoning incidences and poisoning seasonality are rare [21,52]. Our study found that most children were poisoned in the spring and summer. This is similar to the findings of Hamid et al [53], but is inconsistent with the findings of Lee et al [30], who reported that more children are poisoned in winter, possibly because carbon monoxide poisoning cases were excluded from our study. The incidences of carbon monoxide poisoning during winter were high due to heating, leading to differences in findings between our study and the study by Lee et al [30]. The incidences of poisoning in children during spring and summer were higher, possibly because the number and range of children’s activities increase and expand in spring and summer due to the warmer weather, and they are more likely to be exposed to various poisons, leading to unintentionally poisoning [54]. Children have a long break in summer and may spend more time unsupervised, which may increase the risk of unintentional poisoning. Students generally progress to a new grade during spring and summer. Teens may face greater stress brought on by examinations and academic progress during spring and summer. This may lead to high incidences of intentional poisoning during spring and summer [55]. In addition, due to the increase of farming operations and mosquitoes during spring and summer, the toxic substances, such as pesticides, rat poison, and insecticides, appear more frequently. These toxic substances can be easily obtained, which may stimulate some people to suicide. Therefore, high incidences in intentional poisoning were found during spring and summer [9,56]. The results of Lin et al [21] confirmed that the incidences of both intentional poisoning and unintentional poisoning were high in March (spring). The incidence rates of poisoning during spring and summer are high, suggesting the seasonality of poisoning. Our study was a single-center study and no in-depth analysis of other potential influencing factors (such as vacation schedules, environmental changes, and social behaviors) was performed in our study, so the current data are insufficient to support the conclusion on seasonality. Future studies should be conducted based on multi-center data to investigate the impact of seasonality on poisoning in children and possible interventions through more rigorous analysis of longitudinal data and a large sample size.

The proportions of medication poisoning cases, harmful substance poisoning cases, and toxic substance poisoning cases in teens in this study were different from that in non-teens. Medication poisoning cases and toxic substance poisoning cases in teens accounted for higher proportions than in non-teens. Most unintentional poisoning occurred in non-teens, while most intentional poisoning occurred in teens [57]. Intentional poisoning was usually caused by medications or toxic substances [14,22].

In this study, 20 (6.3%) patients were poisoned by multiple poisons. This is lower than the 19% reported by Lee et al [30] for Taiwan. There are regional differences in the control policies between prescription drugs and over-the-counter drugs. This may affect the accessibility and circulation of medications, thereby affecting the incidence of poisoning. In addition, methodological differences, such as differences in case selection criteria and data sources, may also have an impact on the results of statistical analysis. Such a difference may be associated with the culture, social environment, whether prescription drugs are easily obtained in the study area, and research methodology. Both our study and the study in Taiwan have shown that poisoning in children is usually caused by a single substance [30], the children were usually poisoned unintentionally [14,41], and some unintentional poisoning cases were caused by medications from guardians of the children [58]. The bitter taste of some medications for adults may discourages the children to taste it again. This can reduce sustained intake in children to some extent. The taste of the medications, dosage forms (such as syrups and sugar-coated tablets), and children’s exploratory behavior can affect the amount of poison ingested. Medication poisonings in children are mostly caused by a single drug. This is possibly due to the taste, accessibility, and storage method of the drug and behavioral characteristics of children, which needs to be further studied.

Teens had a higher incidence of poisoning caused by multiple substances than a single substance compared with non-teens, possibly because the incidence of intentional poisoning in teens was higher than unintentional poisoning, and the incidence of intentional poisoning caused by multiple substances in teens was higher than that caused by a single substance [22,30]. Poisoning caused by multiple substances was usually associated with a higher rate of hospitalization [30]. Generally speaking, the greater the number of poisons, the more severe the poisonous reaction, the more complicated the treatment, and the more time needed for treatment. One pediatric patient in our study orally took 5 types of medications, and hospitalization for kidney dialysis was required in addition to the basic treatment. This suggests that a timely risk assessment and healthcare resource allocation are necessary for children who are poisoned by multiple substances to ensure they can receive appropriate health care. Poisoning prevention should focus more on identifying exposures to multiple substances. Emergency department physicians should pay attention to the possibility of poisoning caused by multiple substances when receiving the poisoned patients, and should be more cautious in the treatment process and consider the more serious consequences that may be brought by a variety of poisons. Hospitals can institute standardized assessment procedures in the emergency department, including detailed medical histories and rapid toxicology screening, to improve the diagnosis and treatment of poisoning caused by multiple substances. Toxicology screening has important clinical value for high-risk patients (such as being intentionally poisoned, having a disorder of consciousness, and being poisoned by multiple substances). It can be used to quickly identify poisons and help to guide treatment. However, many emergency departments in China perform evaluations relying on medical history and clinical manifestations, and standardized screening has not been widely used, especially in resource-limited environments. Toxicology screening faces resource challenges, and some tests are time-consuming. Timeliness is important in rapid decision-making for emergency care, and comprehensive screening may increase healthcare costs and workload. A more cost-effective strategy is to selectively screen high-risk patients. Future studies could investigate the cost-effectiveness of screening strategies to optimize the emergency management of poisoning in children.

This study found that unintentional poisoning was common in the poisoned pediatric patients and the incidence rate of intentional poisoning in teens was significantly higher. Unintentional poisoning was common in the poisoned pediatric patients, which was similar to the results found in Ethiopia (73.5%) and Singapore (89.4%). The studies by Bacha et al [14] and Koh et al [41] found that most poisoning incidents in children are unintentional. Among all age groups, teens had more intentional poisonings than non-teens. This is similar to the results reported by America’s poison centers [24,25]. The incidence of serious consequences caused by intentional poisoning is approximately 3 times higher than that caused by unintentional poisoning [23], so determining whether a child has been poisoned intentionally or unintentionally is critical to help doctors be more vigilant and give more appropriate treatment at an early stage. This is also helpful to identify whether a child has psychosocial problems and to provide them with psychological treatment or family support in the follow-up treatment process, because children with psychosocial problems are more likely to be intentionally poisoned [51,59].

Our study found that teens had a higher incidence rate of intentional poisoning than non-teens, which is similar to the results of Matalová [22]. Higher incidences of intentional poisoning in teens may be associated with their emotional instability, and an increase of stress from school and society [8,50]. The teen years are a period of life in which individuals undergo rapid physical and psychological changes with rapid mood swings. This can cause teens to be more prone to extreme behavioral responses. Although several studies have shown a higher incidence of poisoning in teens, independent studies on this specific age group are insufficient. On the one hand, the existing literature mostly focuses on data description and lacks in-depth discussion on the specific mechanism of poisoning in teens. On the other hand, poisoning in teens often involves complex factors, such as mental illness, drug abuse, and environmental exposure. This poses a challenge to comprehensively analyze its causes and develop effective interventions. Our study verified that teens are at high risk of poisoning. However, future research should focus on the following aspects: (1) systematic study of high-risk behaviors and psychological factors associated with poisoning in teens, such as impulsive decision-making and emotional fluctuations; (2) an in-depth assessment of the impact of social and environmental factors (such as family environment and inappropriate exposure to medications) on the risk of poisoning; (3) develop behavioral intervention strategies and drug safety education programs for teens to effectively reduce the risk of poisoning.

The single-factor analysis results have shown that female teens had a higher incidence rate of intentional poisoning than male teens, which is similar to the results of other studies conducted in China and other countries [23,51,60]. In the multivariate analysis, the correlation between gender and intentional poisoning after adjustment of potential confounders was no longer significant, possibly because factors teen years and history of mental illness played a more important role in intentional poisoning, weakening the independent influence of gender. Previous studies have shown that female teens are more likely than male teens to attempt suicide due to feelings of helplessness, loneliness, and conflicts with parents and peers, possibly because female teens are more emotionally sensitive than male teens, and have a clearer perception of conflicts [45,46]. With the popularity of the internet, teens have more opportunities to access online information, and may also be exposed to suicidal behavior, ideation, and intent on the internet. Women are more easily affected by online suicidal behavior, and such online suicide imitation aggravates the existing gender differences [61,62]. Men and women use different suicide methods. Compared with men, women are more inclined to suicide by poisoning [59,63]. Due to these factors, the effect of gender on intentional poisoning still needs attention. Future studies can focus on the interactions between gender and other factors (such as teen years and history of mental illness) to reveal the potential effect of gender on intentional poisoning. In clinical practice, the possibility of intentional poisoning in female teens needs to be considered, particularly when altered states of consciousness are detected in the female teens or they refuse to provide their medical histories [21].

Our study also found that children with a history of mental illness are more likely to be intentionally poisoned, which is similar to the results of most other studies [40,51,64]. The incidence of intentional poisoning in teens with a history of mental illness accounted for the highest proportion compared with other age groups. The simplest measure to reduce the incidence of intentional poisoning in children with a history of mental illness is to prevent them from using various means [65]. Family members of the children with a history of mental illness should properly store medications, especially psychotropic medications, and poisons. The incidence of suicide in children can also be reduced through schools and society, such as helplines in schools and public education, to increase students’ knowledge and reduce the sense of shame in children with a history of mental illness [65]. In our study, we sought to determine whether poisoned children had a history of mental illness based on their medical records and information provided by their family members. Some patients with mental health problems that had not received a formal diagnosis for mental illness might be underidentified. This might lead to an underestimation of the incidence of poisoned children with a history of mental illness. Healthcare institutions should use more standardized screening tools for mental health, perform timely assessments and interventions with children with a history of mental illness, and give them more emotional and psychological support to reduce the risk and incidence of intentional poisoning and mental illness. In addition, we should also be vigilant about the possibility of unintentional poisoning in children with a history of mental illness. In our study, 2 children with a history of mental illness were unintentionally poisoned by orally taking large doses of painkillers. These 2 cases suggest that more attention should be paid to the improper use and storage of medications in a household, including children with a history of mental illness. Future studies need to collect more data to identify the specific distribution and characteristics of different substances involved in intentional poisoning.

The pairwise comparisons of poisons found that children who were intentionally poisoned did not tend to choose toxic substances compared with medications. This was different from the findings of Li et al [8], who reported that people who were intentionally poisoned in China preferred toxic substances for suicide. It is possibly because China’s supervision of toxic substances is stronger than before, and toxic substances are no longer as easy to obtain. Our hospital is located in the capital city of Sichuan Province, China, and few of our emergency department patients come from rural areas. Most poisoned children who live in the rural areas are intentionally poisoned with toxic substances [8]. Therefore, the location of our hospital may have an impact on the results of our study. In recent years, mental illness has received more attention from children’s family members. Children with mental illness have more treatment opportunities [66]. Some mental illness can be treated with medications. If the medications can be easily reached by children, children with mental illness may choose medications instead of toxic substances for intentional poisoning. To prevent intentional poisoning in children, family members should carefully manage medications and toxic substances, especially medications for mental illness [9].

This was a retrospective study. The data in this study may be incomplete due to missing data caused by variables. This study was a single-center study. The data in this study were collected from a tertiary Grade A hospital in a capital city of a province, so the data do not represent the situations of the poisoned children in the whole city or even the country. The data were collected from the hospital information system. Family members might conceal information concerning intentional poisoning and poisoning caused by alcohol or illegal drugs to protect the family’s reputation, so the data might be inaccurate. Patients or their family members might inaccurately describe poison entry, so reporting bias might exist. Supervision from family members, environmental exposure, and social activities associated with seasonality were not analyzed in depth in this study. The impact of seasonality on poisoning was observed, but it is not sufficient to draw a firm conclusion. Multi-center data and long-term monitoring are required to validate the impact of seasonality on poisoning in children and identify opportunities for intervention. In addition, the study only included emergency cases. Some poisoning cases (such as out-of-hospital poisoning deaths, and mild poisoning cases that did not visit the hospital) might be omitted, thus underestimating the actual incidence of poisoning. This could limit the generalizability of the results and the representation of patients from urban and rural areas. A multi-center study is required to collect diverse data from different regions. More appropriate data collection (such as collecting more social background data) and analysis methods (such as introducing big data technology and machine learning algorithms) should be adopted to reduce the impact of these limitations on research and validate research findings across different settings, thereby providing stronger data support for policy formulation and prevention measures.

Conclusions

This study provides a comprehensive analysis of pediatric poisoning cases at a tertiary emergency department in Chengdu. Medications remain the leading cause of poisoning, with higher incidence observed among females and teenagers. The findings also indicate seasonal trends, with increased cases in spring and summer. Intentional poisoning, particularly among adolescents, is a growing concern and highlights the need for integrated mental health screening and support services for high-risk groups. The study also underscores critical gaps in pre-hospital management, as a notable proportion of patients received inappropriate or ineffective interventions at home. These findings emphasize the importance of community-based education programs aimed at improving caregiver awareness of first aid measures and safe medication storage practices. From a public health perspective, the implementation of standardized poison prevention strategies is urgently needed. These may include regulatory measures for child-resistant packaging, improved prescription drug control, public awareness campaigns, and the establishment of a national poison information hotline to provide timely guidance during poisoning incidents. To enhance future prevention efforts, we recommend strengthening mental health support services in schools, introducing early screening programs for at-risk adolescents, and conducting multi-center studies to validate these findings across diverse populations. Addressing these issues collectively may contribute to a reduction in pediatric poisoning rates and improved clinical outcomes.