Conversation: The conversation between human and AI assistant.
[|Human|] Circular rash appears on torso after hot shower usually gone by end of day. Is not raised and not itchy. My sister has the same splotches , she lives in a different state. Hers appeared 3 years ago same symptoms only now she has multiple red splotches and they dont disappear. Any idea what this may be?
[|AI|]  Hello. Thanks for writing to us at Chat Doctor This is suggestive of cholinergic urticaria. It clinically presents as either red rashes or raised welts. Itching is subjective. The trigger in this type of urticaria is often a change in core body temperature. Certain well known triggers are e.g. exercise, hot shower, spicy food, strong emotions etc. Once the cause of the rash is identified, it may be possible to avoid situations that trigger it e.g. hot shower in your case. However, in many cases it may be difficult to stop certain triggers like sweating, particularly in warm climates and if exercising is part of a daily routine. It is chronic and is best treated with a single does of an oral antihistamine e, g cetirizine 10 mg once daily, can be helpful in preventing the condition from arising. Treatment is long termRegards