Fixed Eruption to Sulphasalazine

A.J. Kanwar, M. Singh, M. Yunus, M.S. Belhaj, Department of Dermatology, Faculty of Medicine, Al-Arab Medical University, Benghazi (Lybia) References Avella, J.; Binder, H.J.; Madsen, J.E.; Askenase, P.W.: Effect of histamin H2-receptor antagonists on delayed hypersensitivity. Lancet i: 624-626 (1978). Festen, H.P.M.; De Pauw, B.D.; Smeulders, J.; Wagener D.J.T.: Cimetidine does not influence im-munological parameters in man. Clin. Immunol. Immunopathol. 21: 33-38 (1981). Thornes, R.D.: Cimetidine and brucellosis. Lancet ii: 217 (1982). Kaaman, T.: Cell-mediated reactivity in der-matophytosis: difference in skin response to purified trichophytin in tinea pedis and tinea cruris. Acta derm.-vener., Stockh. 61:119:123 (1981). Sir, Though there are several reports in the literature of fixed-drug eruption (FDE) due to various sulphon-amides like sulphadiazine, sulphaphenazole, sulphadi-amidine etc. [2,3], we did not come across any instance of FDE in which sulphasalazine (salicyl-azosulpha-pyridine) was responsible. In the present communication we describe a case of FDE which was proven to be due to sulphasalazine and there was a cross-reactivity with sulphapyridine. To our knowledge, this is the first reported occurrence of such a reaction due to this drug. Case: A 38-year-old male who had ulcerative colitis and was being treated with sulphasalazine (Salazopyrine®), 500 mg 4 times a day, with occasional systemic steroids (prednisolone, 10-15 mg a day) for the past 2 years, developed FDE on glans penis. He had 5 such previous episodes in the past and, interestingly enough, the lesions occurred only when he had been taking sulphasalazine alone without steroids. Combination therapy did not result in any skin eruption. Provocation tests were carried out at weekly interval with sulphasalazine (500 mg), sulphapyridine (500 mg), sulphadiazine (500 mg), sulphaphenazole (500 mg), sulphamethoxazole (500 mg) and sulphadiami-dine (500 mg). All these drugs were given orally. The patient showed flaring of FDE lesions with sulphasalazine and sulphapyridine within hours and with the latter drug there were 3 more new lesions on the trunk. However, other sulphonamides failed to provoke any reaction. Our patient developed FDE to sulphasalazine as well as to sulphapyridine, which is a breakdown product of sulphasalazine. A review of the recent literature on fixed eruptions [1] failed to disclose an instance of FDE caused by this drug. Thus sulphasalazine can now be added to the ever increasing list of drugs capable of producing an FDE. References