Case Report: Rapid Response to Low-Dose Thalidomide in a Case of Severe Steroid Recalcitrant Erythema Nodosum Leprosum.

Erythema nodosum leprosum (ENL), or type 2 lepra reaction, presents with crops of evanescent, tender erythematous nodules accompanied by fever, arthralgia, weight loss, malaise, and organ-specific manifestations, and is seen in borderline and lepromatous leprosy. The drugs approved for ENL include nonsteroidal anti-inflammatory drugs, systemic steroids, thalidomide, and clofazimine. The management of ENL is challenging because long-term steroid use leads to steroid dependence. Our patient had severe steroid recalcitrant ENL with vesicular and pustular lesions mimicking Sweet's syndrome, and was treated effectively with a low-dose thalidomide regimen (100 mg/d) as opposed to the high dose (400 mg/d) recommended in the literature. We discuss the patho-mechanics and clinical utility of a low-dose thalidomide regimen as an effective treatment option for ENL.