Dear Editor,
I read with interest the study by Modrzyński and Zawisza on possible induction of oral allergy syndrome during specific immunotherapy in patients sensitive to tree pollen [1].
The identification of allegrens for allergy is frequently accomplished by a history taking, a careful environmental assessment, and various testing methods. Among allergy testing techniques, allergen skin-prick test has several advantages over other testing methods. First, allergen skin-prick test is known to be the most convenient and least expensive screen method to detect allergens. Second, allergen skin-prick test is a relatively safe way to recognize the presence of allergen specific IgE. Finally, allergen skin-prick test is fairly quick to provide an in vivo assessment of biologically relevant IgE antibodies [2]. Another commonly used testing method is radioallergosorbent test (RAST) that may give comparable information from a serum sample, compared to that obtained from skin tests. However, RAST has some limitation in the evaluation and diagnosis of allergy due to lower sensitivity and higher cost than allergen skin-prick test. Indeed, it has been demonstrated that about 25% of patients with a positive skin test have a negative RAST [3]. In this research, authors conducted allergen skin-prick test only before the immunotherapy, not after immunotherapy, even though sIgE levels in sera were determined before the immunotherapy and at 6, 12, and 18 months of therapy. Thus, if authors had performed allergen skin-prick tests for the entire immunotherapy period, along with serum test, the results from this study would become more solid and clear. Allergic rhinitis is commonly associated with demonstrable nonspecific bronchial hyper-reactivity on bronchial challenge with methacholine, histamine, or cold air [4]. The possible mechanisms of association between allergic rhinitis and asthma are nasal inflammation which contributes to development of bronchospasm by the nasobronchial reflex, inflammatory nasal cytokines secreted from the nose which could be aspirated into the lower airway inducing bronchial inflammation [5], and persistent inhalation of cold dry air via mouth breathing [6]. However, authors didn’t show the pulmonary function testing and any comment for concurrent asthma in the present study. Thus, it is not clear if one case of bronchial asthma found in control group was newly diagnosed or previously retained asthma.
Immunotherapy involves the subcutaneous injection of increasing doses of allergens until reaching a maintenance dose [7]. However, because each individual has a different degree of sensitivity to an allergen, a dose for each patient should be carefully determined to maximize safety while still achieving the desired clinical improvement. The most common limiting factor of dose increasing is large local dermal reactions at the site of injection. Thus each patient should be injected at different doses of allergen and may show different responses, including oral allergy syndrome. However, authors didn’t present grading criteria and grading of allergen skin-prick test, dermal reactions, in the present research. Addition of such information would provide evident demonstration of the association at various doses of allergen and induction of oral allergy syndrome during immunotherapy.

Sincerely,
Yang-Deok Lee
Department of Internal Medicine,
Eulji University Hospital,
Eulji University School of Medicine,
1306, DoonSan-Dong, Seo-Gu, Daejeon 302-799,
South Korea

References:
1.Modrzyński M, Zawisza E: Possible induction of oral allergy syndrome during specific immunotherapy in patients sensitive to tree pollen. Med Sci Monit, 2005; 11(7): CR351–55
2.Bernstein IL, Storms WW: Practice parameters for allergy diagnostic testing. Joint Task Force on Practice Parameters for the Diagnosis and Treatment of Asthma.The American Academy of Allergy, Asthma and Immunology and the American College of Allergy, Asthma and Immunology. Ann Allergy Asthma Immunol, 1995; 75: 543–625
3.Hamilton RG, Kagey-Sobotka A: In Vitro Diagnostic Tests of Ig-E Mediated Diseases. In: Kemp SF, Lockey RF (edits). Diagnostic Testing of Allergic Disease. New York, Marcel Dekker, 2000; 89
4.Watson WT, Becker AB, Simons FE: Treatment of allergic rhinitis with intranasal corticosteroids in patients with mild asthma: Effect on lower airway responsiveness. J Allergy Clin Immunol, 1993; 91: 97–101
5.Lack G: Pediatric allergic rhinitis and comorbid disorders. J Allergy Clin Immunol, 2001; 108: S9–15
6.Dykewicz MS, Fineman S, Skoner DP et al: Diagnosis and management of rhinitis: Complete guidelines of the Joint Task Force on Practice Paramaters in Allergy, Asthma and Immunology. Ann Allergy Asthma Immunol, 1998; 81: 478–73
7.Weber RW: Immunotherapy with allergens. JAMA, 1997; 278: 1881–87

Keywords: Desensitization, Immunologic - adverse effects, Hypersensitivity - etiology, Immunoglobulin E - blood, Pollen - immunology, Skin Tests, Trees - immunology