Combined cold urticaria and cholinergic urticaria--clinical characterization and laboratory findings.

Thirteen patients with both cold and cholinergic urticaria are reported. There was considerable variability, particularly in the cold urticaria which was of the common cold contact type in seven patients, of the generalized cold induced cholinergic type in two and in four patients the lesions induced by direct contact with ice were morphologically like cholinergic urticaria, but appeared despite prior application of an acetyl choline antagonist. The natural history, laboratory findings and the effects of therapy are discussed.