Cholinergic urticaria is a type of urticaria associated with sweating, such as from exercise, a hot bath or shower, or overheating. Patients develop wheals (pink, flat-topped papules and plaques) that are transient after the inciting trigger. Studies have also shown that patients may develop angioedema and experience extracutaneous symptoms such as dizziness, abdominal pain, and wheezing. In severe cases, anaphylaxis may occur.

Cholinergic urticaria may be associated with atopic dermatitis and other allergies. The presence of other atopic conditions is associated with more severe disease and longer disease duration.

If features of anaphylaxis are present (hypotension, stridor, or respiratory distress, etc), immediate intervention is needed to secure the patient's airway and prevent circulatory collapse. Administer intramuscular or subcutaneous epinephrine, repeated at 15- to 20-minute intervals as needed. Observe the patient for rebound phenomena. Observation for 2-4 hours is usually sufficient unless the reaction is severe. Oral and parenteral H1-antihistamines take at least 1 hour to relieve skin symptoms. They are not effective against airway obstruction or shock from anaphylaxis.