Urticaria and the role of antihistamines in pruritus

الملخص EN

About 20 % of the population experience episodes of urticaria at least once in their lifetime.

Type I hypersensitivity reactions may be involved in acute conventional and contact urticaria, but uncommonly in chronic urticaria.

The diagnosis of urticaria can often be made only from the history.

Patients may not present with skin lesions, so you should ask for history of drug intake and search for an infective focus.

Nearly 50 % of chronic idiopathic urticaria is associated with histamine-releasing autoantibodies.

Episodes of urticaria lasting for more than 24 hours need to be evaluated for vasculitis and systemic disease.

Antihistamines are the mainstay of treatment.

Caution is to be taken while combining antihistamines with drugs like erythromycin and ketoconazole, for risk of cardiac arrhythmia (torsade de pointes).