Regular sweating activities for the treatment of cholinergic urticaria with or without acquired idiopathic generalized anhidrosis.

Cholinergic urticaria (CholU) decreases affected individuals' quality of life because they must avoid stimuli including exercise and hot bathing. Although case reports have indicated that regular sweating activities are effective for CholU with hypohidrosis, little evidence is available. This retrospective medical record review examined CholU patients who received any form of treatment at our hospital. Twenty-seven cases (78% men; median age 22 years, range 12-70 years) were analyzed. Fourteen (52%) patients had acquired idiopathic generalized anhidrosis (AIGA). Among the 12 patients receiving sweating therapy (4 with, 8 without AIGA), improvement of symptoms was confirmed in 11 (92%; sweating therapy alone: n = 5, with H1 blocker: n = 5, with steroid pulse: n = 1) including 8 (67%) showing complete response (CR). In this sweating-therapy group, CR was achieved by six of the eight (75%) patients without AIGA and two of the four (50%) patients with AIGA. Among the 15 patients without sweating therapy, symptom improvement was observed in 9 (60%; steroid pulse: n = 7, H1 blocker: n = 2) including 1 (7%) achieving CR. Sweating therapy was safely undertaken except in one case in which the patient showed angioedema and anaphylaxis. Regular sweating activities could be a potential therapeutic option for CholU patients.