Dyes and preservatives in oral antihistamines

Abstract
SUMMARY: Antihistamines are commonly used in the treatment of urticaria. Some antihistamines contain dyes and preservatives which have themselves been shown to produce or exacerbate urticaria; the presence of these substances is not indicated in the usual formularies and a list of commonly prescribed antihistamines is presented, detailing the azo dyes, other dyes and preservatives contained therein.