Evaluation of a patient with cold and cholinergic urticaria.

A-20-year-old male Army paratrooper presented with a history of inducible urticaria associated with exercise as well as cold exposure. Upon evaluation, he not only had a positive ice cube test, but also had a positive mecholyl skin test with numberous satellite lesions and generalized punctate urticaria following exercise challenge. Thus, he appeared to have combined cold and cholinergic urticaria. When mediator release was examined during cold and exercise challenge, histamine release was observed in each instance; a rapid rise and fall of plasma histamine was seen after cold challenge, while a lag phase followed by sustained elevation of plasma histamine was associated with exercise challenge. This represents the fourth reported case of combined cold and cholinergic urticaria and is the first in whom mediator release was assessed. The time-course of histamine release was characteristic of each disorder.