The role of contact allergy to aeroallergens in atopic dermatitis.

In some patients with atopic dermatitis (AD), delayed-type allergy to aeroallergens, such as house dust mite, can be demonstrated by patch testing. Positive patch tests can be expected only in patients with AD and, in them, only to aeroallergens to which type 1 reactions have also been demonstrated. In an as yet unknown number of such cases, aeroallergens appear to play a role in AD. Studies to date have varied too widely in experimental method and design to allow more definite conclusions to be drawn. It is essential that future studies are standardised with regard to patch test system and designed to include adequate controls and assessment of relevance.