Cholinergic urticaria (CU) is a type of hives brought on by raised body temperature. It typically develops when you exercise or sweat. More often than not, CU appears and disappears on its own within a few hours. In severe cases, CU can sometimes be related to exercise-induced anaphylaxis.

Why did I suddenly develop cholinergic urticaria?

Share on Pinterest Cholinergic urticaria is a skin rash that can develop if a person gets too hot. Cholinergic urticaria tends to occur very quickly after a person begins to sweat or gets overheated. The rash can occur anywhere on a person's body but may be more likely to appear on a person's trunk or arms.

What is the main cause of urticaria?

Urticaria occurs when a trigger causes high levels of histamine and other chemical messengers to be released in the skin. These substances cause the blood vessels in the affected area of skin to open up (often resulting in redness or pinkness) and become leaky.