Skin prick test reactivity to a battery of common allergens was examined in 26 adults with atopic eczema, in 9 patients with allergic rhinitis and in 10 nonatopic controls. In both patient groups, reactivity was most frequent for grass pollen, followed by rye, house dust mite, tree and herb, with no reactions to food allergens. Repeated tests at weekly intervals were less reproducible in weak reactions and in severely affected eczema patients compared to those lightly affected. Skin prick tests are therefore reliable and reproducible in atopics and provide means to counsel patients on avoidance of eliciting agents of their disease.