Cetirizine induced urticaria

To the Editor

Cetirizine in the carboxylic acid metabolite of hydroxyzine used commonly in the treatment of acute and recurrent episodes of urticaria.[1] Use of this drug causes a decrease in immediate release of histamine, in the detection of platelet activation factor, in the influx of eosinophils and prostaglandin D2 generation.[2] Side effects include headache, dizziness, drowsiness, agitation, dry mouth and gastrointestinal discomfort. Recently a 25-year-old Hindu female presented to us with contact dermatitis involving the hands. She was prescribed cetirizine 10 mg HS along with topical corticosteroid ointment. She took this medication for 2 days and came back on third day with generalised urticarial reaction. The lesions appeaed within half an hour of the intake of third dose of cetirizine.

A complete physical examination and laboratory investigations were done to exclude other cases of urticaria. Cetirizine was stopped and the patient was treated with dexchlorpheniramine maleate 2 mg twice daily with subsidence of lesions within 3 days.

Rechallenge with ¼ tablet of cetirizine produced pruritus and urticarial wheels. To our knowledge, urticaria occurring after cetirizine use has not been described in literature although it has been mentioned as a rare complication after use of terfenadine,[2] which also is an antihistaminic drug. This case report is interesting because here an antihistaminic drug is causing urticaria for which it is used as a therapeutic modality.