Atopic dermatitis and aeroallergen contact sensitivity.

Atopic dermatitis (AD) may be worsened by ingested foods or contact with irritants. We have identified 10 patients (six male and four female subjects, aged 1 to 54 years) with AD and contact sensitivity to a variety of aeroallergens. Marked improvement in skin symptomatology was noted when these patients were removed from their usual environment. The patients had markedly positive immediate wheal-and-flare reactions to a variety of aeroallergen extracts in response to prick tests and were subsequently patch tested on uninvolved skin with aeroallergen extracts (1:20 wt/vol, 50% glycerine) that elicited positive prick tests. Patch tests were applied for 48 hours, removed, and then were interpreted 24 hours later. Fifty percent glycerine was used as a negative control. Significant delayed cutaneous responses to a variety of aeroallergens were noted: house dust mite, tree, grass and weed pollens, animal danders, and various molds. Positive delayed cutaneous responses correlated strongly with aeroallergens identified in the patient's environment and/or suspected by the patients as provocateurs of their AD. Delayed cutaneous reactions were negative to aeroallergens not historically relevant to their AD. We conclude that aeroallergen contact may play an important role in selected patients with AD. The demonstration of immediate and delayed cutaneous responses in AD suggests both IgE and cell-mediated hypersensitivity as contributory mechanisms.