The condition is caused by an overreaction of the immune system to the release of histamine and other chemicals in response to the increase in body temperature.

Cholinergic urticaria typically presents with a number of small papular hives all over the body, that involve cutaneous inflammation (wheals) and severe nerve pain, which usually develops in response to exercise, bathing, staying in a heated environment, spicy foods, or emotional stress.

Forced perspiration by excessive body warming (hot bath or exercise) used daily may reduce the symptoms through exhaustion of inflammatory mediators.

[15] [16] The wheals, hypohidrosis, and pain seems to result from the low expression levels of acetylcholinesterase (AchE) and cholinergic receptor, muscarinic 3 (CHRM3) in the eccrine gland epithelial cells.

Though overall research is limited, various studies indicate that CU is relatively common across populations with prevalence rates reportedly ranging from 5% to 20% (depending on locale, race, and age).

[19] The vast majority of cases are reported to be mild, and proportionally few individuals seek medical attention regarding the condition.