Contact allergy to antihistamines is not common

Abstract

Topical antihistamines are available as creams, lotions, eyedrops, nasal preparations, aerosols, and suppositories. Antihistamines (or H 1 ‐receptor antagonists) have antipruritic properties, a mild local anesthetic effect and may also diminish capillary permeability. They can be classified into 6 groups by their chemical structure (1): alkylamines, ethanolamines, ethylenediamines, phenothiazines, piperazines, and other H1‐receptor antagonists. Application to the skin is generally considered to carry an unacceptably high risk of sensitization (1, 2). Recently, several cases have been reported of allergic contact dermatitis from topically‐applied doxepin hydrochloride, a tricyclic antidepressant that has very potent antihistaminic activity (3–5).