Apremilast in chronic recalcitrant erythema nodosum leprosum: a report of two cases.

Erythema nodosum leprosum (ENL) is a severe immune reaction commonly encountered as a complication in patients with multibacillary leprosy. Management of chronic ENL in leprosy is challenging and necessitates the use of systemic immunosuppressants, including corticosteroids and thalidomide. No single drug is universally effective and most current therapeutic agents carry a significant risk of systemic toxicity. Apremilast is an orally effective phosphodiesterase-4 inhibitor with a potent immunomodulatory action and is clinically effective in inflammatory conditions like chronic plaque psoriasis. We report two patients with poorly controlled chronic ENL, despite the use of multiple therapeutic agents. Both patients demonstrated significant clinical improvement with apremilast, without any adverse effects, thereby suggesting its potential as a novel therapeutic option in chronic ENL. What's already known about this topic? Erythema nodosum leprosum (ENL) is an immune-mediated reaction in patients with multibacillary leprosy, with chronicity and recurrences frequently reported. Management of chronic ENL requires systemic immunosuppressants like corticosteroids, which may not be universally effective and carry a risk of serious toxicity. Apremilast is an oral immunomodulator with good efficacy in inflammatory conditions like chronic plaque psoriasis. What does this study? Apremilast may be an effective therapeutic agent in patients with chronic ENL.