Volume 22 Number 2 February 2016 Letter Dapsone for treatment of erythema nodosum

Johanna Song, Kareem Halim, Ruth Vleugels, Joseph Merola, Joseph Merola
Letter Erythema Nodosum (EN) is the most common form of septal panniculitis, with over 100 reported infectious, malignant, inflammatory, idiopathic, and autoimmune causes [1,2]. The histopathology reveals a mixed inflammatory infiltrate with lymphocytes, histiocytes, neutrophils, and eosinophils in subcutaneous fat septae accompanied by immune complex deposition [3]. Treatment is divided into symptomatic therapy with non-steroidal anti-inflammatory drugs (NSAIDs), systemic corticosteroids, or
more » ... rticosteroids, or therapy targeting the underlying cause of EN when identifiable. We hypothesized that dapsone, an antibacterial agent with anti-inflammatory properties that are particularly effective in conditions characterized by abnormal or dysfunctional neutrophil function, might be an effective treatment for EN [4]. Despite being utilized as an anti-inflammatory agent in many cutaneous conditions, to our knowledge, no existing reports highlight the use of dapsone for EN. IRB approval was obtained to search the Partners Healthcare Research Patient Data Registry, a centralized registry of more than 1.8 million patients, for individuals with a diagnosis of EN and a prescription for dapsone between January 1993 and June 2014. Of 25 patients identified, three were confirmed as having received dapsone specifically for the treatment of EN (Table 1).