Case of cholinergic urticaria accompanied by anaphylaxis

Cholinergic urticaria occasionally occurs in combination with anaphylactic symptoms. However, this has not been widely reported. Herein, we report the case of a 14-year-old Japanese male who was diagnosed with cholinergic urticaria accompanied by anaphylaxis. The patient, who was suffering from atopic dermatitis and bronchial asthma, had developed wheals after exercising or bathing, which would have increased his core body temperature, since summer 2014. He experienced two episodes of severe systemic symptoms and wheal development when he took a bath after eating in December 2014 and the following January. His symptoms included wheezing, numbness of the lips, respiratory distress, blindness and fainting. Laboratory tests revealed the following results: serum IgE level, 7060 IU/mL; titers of specific immunoglobulin E antibodies against Malassezia and MGL_1304, 31.70 UA/mL and 112.5 ng/mL, respectively. A histamine release test against human sweat revealed a class 4 response. Skin prick and intradermal tests against autologous sweat produced immediate-type positive reactions. According to these findings, we diagnosed him with the sweat-hypersensitivity type of cholinergic urticaria accompanied by anaphylaxis. He was successfully treated with lafutidine, a histamine H₂ receptor antagonist, in combination with fexofenadine. It is important for dermatologists to be aware that cholinergic urticaria can progress to anaphylaxis.