The role of mite allergen in chronic urticaria.

Fifty-two patients with chronic urticaria were tested intradermally with mite allergen (Dermatophagoides farinae). None had any past history of any other atopic diseases. Thirty of the 52 patients gave positive skin tests to mite allergen. A good correlation between skin sensitivity to mite allergen and in vitro mite antigen-induced histamine release from leucocytes was observed. These facts suggest that a mite may be an important role in chronic urticaria.