Lupus erythematosus due to anti-tuberculosis drugs: A report of two cases and review of the literature

Abstract

An estimated incidence of drug-induced lupus erythematosus caused by all drugs is 15 000-20 000 cases a year, and represents approximately 5-10% of the total number of patients with systemic lupus erythematosus. Objective: Drug-induced lupus is well known. Through this work; we recall the principle clinical, biological and immunological characteristics. The existing literature on the subject is reviewed. Observations: We report two cases of drug-induced lupus erythematosus caused by anti-tuberculosis drugs. The patients were under isoniazid and rifampicin to treat pulmonary tuberculosis. Both were onset cases (3 and 4 months) that occurred in women (37 and 58 years old). The common features were fever, arthralgia, myalgia, a malar rash, and the presence of anti-histone autoantibodies. The treatment consisted of the interruption of the anti-tuberculosis drugs and a bolus of methyl-prednisolone during 3 days relayed by an oral corticosteroid. The evolution was favourable after few months of corticosteroids. Discussion: The suspicion of drug induced SLE (D-SLE) can be made if the drug was given prior to the occurrence of syndrome; the syndrome regresses on it's withdraw and if recurrence occurs on rechallenging with the suspected drug. Such rechallenge is always dangerous and also non-ethical. These drugs could act in two ways: (i) Due to their peculiar pharmacological properties which are dose related e.g. hydralazine, procainamide, anticonvulsants and isoniazid etc. and (ii) as a hypersensitivity reaction which is rare and not dose related e.g. sulfonamide, methyldopa and oral contraceptives etc. The mechanism of D-SLE is hypothesized in multiple reports. The overall prognosis remains favourable although occasional lifethreatening cases have been reported in the literature. Constant pharmacovigilance is crucial for prompt diagnosis and cessation of offending therapy offers the best outcome.