Skin testing in chronic urticaria

In 164 patients with chronic recurrent urticaria, the value of skin tests was investigated, Patch tests carried out with the standard series of the International Contact Dermatitis Research Group and with a series of penicillins revealed positive reactions in 22 (35/162) and 6.9% (11/158), respectively. IN 21.5% (33/152) positive intracutaneous tests to cilligen and/or penicillin G were observed. 35% (51!147) of the patients had one or more positive intracutaneous tests with inhalants. Scratch tests with food allergens showed positive reactions in 12.5% (12/95). There was no difference in results between patients with idiopathic urticaria or angio-oedema and those with physical urticaria. The value of these findings is discussed. Most of the patients with penicillin allergy, were recommended to be on a diet free from milk and milk products. In 50% this was successful.