Generalized bullous fixed drug eruption associated with cetirizine and hydroxyzine demonstrated by patch test

Abstract

Fixed drug eruption (FDE) is characterized by solitary erythematous macules, edematous plaques and bullous lesions that occur at the same place with recurrent exposure to a drug. Though more than 100 drugs have been implicated in leading to FDE, this side effect is more commonly caused by tetracyclines, sulfonamides, sulfone, penicillins, pyrazolones, barbiturates, phenolphthalein, pirazones, aspirin, oral contraceptives and nonsteroidal anti-inflammatory drugs. FDE occurrence has been reported in association with cetrizine, hydroxyzine, loratadine and levocetirizine, which are widely used in the treatment of allergic diseases, such as allergic rhinitis, eczema, asthma, urticaria. Patch, intradermal skin, prick tests or oral challenge test can be performed to identify the agent responsible for FDE. A 43-year-old male patient attended our outpatient clinic with itchy and erythematous rashes with sporadic blisters, starting from dorsum of his feet and spreading to other parts of his body, following oral intake of cetirizine for allergic rhinitis. He described that his eruptions exacerbated with hydoxyzin. Patient's history revealed that he had slightly suffered from the same cutaneous reactions one year ago, after oral administration of cetirizine. On physical examination, multiple, round, erythematoviolaceous, well-defined macules and plaques, with central blisters localized on the trunk, arms and legs were observed. Four months after the lesions regressed, patch test was performed to eight different antihistamines. The test was positive for cetirizine, levocetirizine and hydroxyzine.