The relationship between positive aeroallergen patch test reactions and aeroallergen exacerbations of atopic dermatitis.

Previously we have demonstrated that patient contact with specific aeroallergens can cause flares of atopic dermatitis. In this study we report six additional cases that further document the relationship between positive aeroallergen patch test reactions and aeroallergen exacerbation of atopic dermatitis. In total, we have seen 18 patients (8 male, 10 female; ages 1-54 years) who have noted marked improvement in their skin symptomatology when antigen elimination (or moderation) was instituted as part of their general management. Delineation of inciting allergen was accomplished by a combination of prick tests and patch tests to aeroallergens. On prick testing all patients had markedly positive immediate wheal and flare reactions to a variety of aeroallergen extracts (tree, grass, and weed pollen, house dust mite, animal protein, and mold spores). The same patients were subsequently patch tested on uninvolved, nonabraded skin with allergen extracts at the same concentrations that had given positive prick tests. Patch tests were applied for 48 hr, removed, and interpreted at 48 and 72 hr. Patients reacted to specific aeroallergens with an eczematous eruption at 48 or 72 hr or at both time points. Positive delayed cutaneous reactions correlated strongly with aeroallergens identified in the patient's environment and/or suspected by the patients as inducers of dermatitis. Delayed cutaneous reactions were negative to allergens not historically relevant. Avoidance of aeroallergens that elicited an eczematous reaction at patch test sites resulted in marked improvement or resolution of dermatitis in all patients. Environmental rechallenge with incriminated allergens resulted in flares of dermatitis. We conclude that aeroallergen contact plays an important role in select patients with atopic dermatitis and that the responsible allergens can be elucidated by a combination of prick and patch tests.