Combined cold- and heat-induced cholinergic urticaria.

A 36-year-old white woman with a 20-year history of cutaneous, respiratory, and cardiovascular symptoms triggered by physical activity and by exposure to either heat or cold was evaluated. A routine evaluation for the cause of her condition was positive only for certain physical factors. Cutaneous testing for dermatographism, ice-cube challenge, and exposure to ultraviolet A and ultraviolet B light were negative. A methacholine skin test was positive. Sitting in a cold room (4 degrees C) induced micropapular wheals on exposed areas similar to those classically associated with cholinergic urticaria. Placing both feet in warm water (44 degrees C) induced similar but more intense cutaneous lesions at sites not exposed to heat, light headedness, and severe asthma. Exercise for 10 minutes caused confluent and punctate urticarial lesions. Simultaneous measurement of plasma histamine during cold and heat challenges revealed increases paralleling the course of symptoms. Repeat challenge with cold, heat, and exercise after beginning treatment with both H1 and H2 histamine antagonists resulted in marked reduction in symptoms; however, significant rises in plasma histamines were still noted.