Beneficial Effect of Minocycline as Additional Treatment to Prednisone for Pustular Erythema Nodosum Leprosum.

Introduction: Pustular erythema nodosum leprosum (ENL) is an atypical manifestation associated with chronic ENL. The use of corticosteroid alone might not be sufficient for this condition, and addition of another anti-inflammatory drug is often necessary. Minocycline is a tetracycline antibiotic with anti-neutrophilic properties, which may accelerate the treatment of pustular ENL. This case report aimed to elaborate on the beneficial effect of minocycline for pustular ENL.

Case: We report a case of pustular ENL in a 23-year-old male who had been released from treatment (RFT) of lepromatous leprosy (LL). The patient had been on prednisone for six months as treatment for ENL. The condition recurred when prednisone was tapered to 10 mg daily. Eventually, pustules developed on the erythematous nodules, and the lesions did not improve despite seven weeks of treatment with 40-60 mg prednisone. Later, 100 mg minocycline once daily was given in addition to 60 mg prednisone once daily and improvement was rapidly observed on the ninth day after minocycline administration. This condition was sustained for four weeks with prednisone tapering, and no side effects were reported during the treatment.

Discussion: Minocycline is an antibiotic with anti-inflammatory properties. Only a few studies have been conducted regarding the use of minocycline in chronic ENL, but there was no reported case of minocycline use for pustular ENL in RFT patient. The addition of minocycline to prednisone may accelerate the improvement of pustular ENL. We observed an improvement after the ninth day of minocycline administration compared to seven weeks of prednisone monotherapy. No new ENL lesions occurred during four weeks of minocycline administration therapy.

Conclusion: Pustular ENL is an atypical manifestation of chronic ENL, and the addition of minocycline to prednisone may accelerate its therapeutic effect on the patient.