Cholinergic urticaria

This code represents a form of physical urticaria characterized by small, itchy wheals that appear in response to an increase in body temperature, often triggered by exercise, hot baths, emotional stress, or spicy food. The rash is typically accompanied by itching, burning, or stinging sensations. It is caused by the release of acetylcholine, which stimulates mast cells.

Use this code when documentation clearly indicates a diagnosis of cholinergic urticaria, often described as heat-induced hives or exercise-induced rash. Supporting documentation should specify the trigger (e.g., heat, exercise) and the characteristic appearance of small, pinpoint wheals. This code is appropriate for both acute and chronic presentations of the condition.

• Differentiate from other forms of urticaria; ensure the documentation specifies "cholinergic" or a clear heat/exercise trigger.
• Avoid using non-specific urticaria codes (e.g., L50.9) when cholinergic urticaria is clearly diagnosed.
• Review for any associated anaphylactic reactions, which would require additional coding.