The Incidence of Delayed-Type Hypersensitivity Reactions to Apples Among Patients Allergic to Birch Pollen

The major apple allergen Mal d 1 cross-reacts with the homologous birch pollen allergen Bet v 1 and causes immunoglobulin E (IgE)-mediated immediate-type allergic reactions. In some patients, delayed-type hypersensitivity to apples may develop within 72 hours without evidence of specific IgE or a positive skin prick test (SPT). The aim of the study was to evaluate the concomitance of delayed-type hypersensitivity reactions and immediate IgE-mediated reactions against high- and low-allergenic apple cultivars in patients with birch pollen allergy. Data were obtained from 45 adults with clinical symptoms of birch pollen allergy. Patients were exposed to apple pulp via atopy patch tests (APTs) and SPTs. Levels of IgE specific to Bet v 1 and Mal d 1 were measured with a radioallergosorbent test. Patients allergic to birch pollen showed the highest rate of positive SPT responses to Golden Delicious apples and the lowest rate to low-allergenic cultivar Grey French Reinette. Among these patients, 9% developed delayed hypersensitivity reactions to either Golden Delicious or Grey French Reinette apples; these reactions manifested clinically as erythema with papules (class ++). Fifty percent of APT-positive patients were concomitantly SPT-negative. Here, we show for the first time the clinical relevance of T cell-driven allergic reactions to apples. APTs may reveal type IV sensitization in patients who are negative for the corresponding type I sensitization tests. Thus, utilization of the APT procedure with fresh apple appears to be a valuable tool for the diagnosis of apple allergy and may improve the accuracy of food allergy diagnoses.

Diagnóstico em doenças alérgicas mediadas por IgE / Diagnosis in IgE-mediated allergic diseases

Doenças alérgicas são frequentes na população em geral e estão associadas à sensibilização a alérgenos do ambiente, como alimentos, pólens, ácaros, fungos, insetos e medicamentos. A presença de anticorpos IgE específicos para alérgenos caracteriza a sensibilização alérgica. Esta revisão aborda a orientação atual para correta avaliação das doenças alérgicas. São discutidos os principais métodos para o diagnóstico - determinação sérica de IgE específica e testes cutâneos com alérgenos - assim como, o teste de contato atópico e novas técnicas em desenvolvimento.

Alergic diseases are frequent conditions in general population. These diseases are linked to allergic sensitization to common environmental allergens, like pollens, mites, molds, foods, insects and drugs. Identification of allergen specific IgE antibody characterizes an allergic sensitization. In this review is analyzed the current approach to diagnosis allergic conditions. The authors discuss major diagnostic methods, as serum specific IgE antibody and allergen skin test, atopy patch test and new techniques that are in development.

Atopy Patch Tests for Atopic Dermatitis Patients according to the Concentration and Vehicle for the Cockroach Antigen / 대한피부과학회지

BACKGROUND:Recent studies have attempted to document the correlation of an atopy patch test (APT) and a skin prick test. The results have suggested a possible role of delayed allergic reaction in the development of eczematous skin lesions in patients with atopic dermatitis (AD) OBJECTIVE: The aim of this study was to evaluate the relationship of APT with skin prick test and specific IgE for cockroach antigen. And we attempted to find the optimal vehicle and concentration of APT for cockroach allergy in AD patient. METHODS: We performed APTs in 50 patients with AD with using German cockroach allergens (the extract with different concentrations and vehicles). The reactions were evaluated after 48 hours, and these were compared with the results of the skin prick test and the total and specific IgE levels. RESULTS: The AD patients who had cockroach allergy, according to a skin prick test or the specific IgE level, showed higher positive APT reactionsthan the non-allergic patients to cockroach. The APT reactions showed a significant relationship with the skin prick test and the specific IgE level (85.7%). With regard to the form of cockroach antigen, a positive APT was more frequent with using the powder form that with using the extract. Regarding the vehicle, petrolatum induced higher positive APT reactions than did distilled water. There was a close relationship between the antigen concentration in petrolatum base and a positive APT reaction. Ten and fifty percent cockroach antigen elicited positive APT reactions than did 1% cockroach antigen with using a petrolatum base. CONCLUSION: Petrolatum is an optimal vehicle for an APT for cockroach because an APT with a petrolatum base revealed the highest correlation with cockroach allergy. The dose-response relationship between antigen concentration and the frequencies of positive APT reactions demonstrated that 10% and 50% cockroach antigen is superior to 1% cockroach antigen.

An Evaluation of Cockroach Allergies in Atopic Dermatitis

BACKGROUND: Atopic dermatitis (AD) is primarily influenced by environmental factors including exposure to pollutants and indoor allergens (particularly, house dust mites). Al-though house dust mite antigens are the most prevalent components of indoor allergens in Korea, cockroaches also can be considered to act as an important allergen. OBJECT: This study was done to evaluate the differences in three different atopic patch test (APT) techniques, and the relationship between APT and skin prick test, total IgE, and specific serum IgE level using cockroach allergen. Methods: We performed patch test in 57 patients with AD and 30 normal controls on clinically lesional and normal appearing skin with German cockroach (GC) allergens (extract, as is) in three different techniques (standard, scratch, DMSO). Reactions were evaluated after 48hours, and compared with the results of skin prick test, total and specific IgE levels. Detailed atopy history and severity scoring were taken. RESULTS: In the GC (whole body) prick test positive group, there was 1263.02 IU/ml of total IgE, and this amount was significantly higher than GC (whole body) prick test negative group who had 549.46 IU/ml (P0.05). There was no significant relationship between the positive reactions to patch test and prick test to Ext and As is antigen. The APT results showed no significant concordances with skin prick test and RAST for cockroach antigens. CONCLUSIONS: APT seems to be a different dimension of atopic skin inflammation and may pro-vide further diagnostic information in addition to a patient's history, skin prick test, and RAST results.

A Comparative Study of Atopy Patch Test Using House Dust Mite Antigens with Skin Prick Test and Specific Serum IgE Level in Atopic Dermatitis / 대한피부과학회지

BACKGROUND: In some patients with atopic dermatitis (AD), eczematous skin lesions can be induced by atopy patch test (APT) with house dust mite antigen. The results of APT in patients with AD varies in different studies, probably because of different test techniques. OBJECT: This study was done to evaluate the differences in three different APT techniques, and the relationship between APT and skin prick test, total IgE, and specific serum IgE level. METHODS: We performed patch test in 93 patients with AD and 30 normal controls on clinically lesional and normal appearing skin with commercial house dust mite allergens in three different techniques (standard, scratch, DMSO). Reactions were evaluated after 48hours, and compared with the results of skin prick test, total and specific IgE levels. Detailed atopy history and severity scoring were taken. RESULTS: There were no significant differences in positive APT results with three different techniques and different areas (lesional and normal appearing skin). The APT results showed significant concordances with skin prick test and RAST for house dust mite antigens. But there were no statistical significances between APT results and severity score and total IgE level. CONCLUSION: The correlation of APT and RAST-skin prick test in this study suggests a possible role of delayed allergic reaction in the development of eczematous skin lesions after house dust mite antigen contact. The APT seems to be a valuable tool in diagnostic work-up in patients with atopic dermatitis.