Recognizing and managing the immunologic reactions in leprosy

J Am Acad Dermatol. 2014 Oct;71(4):795-803. doi: 10.1016/j.jaad.2014.03.034. Epub 2014 Apr 24.


Immunologic reactions are an important aspect of leprosy that significantly impacts the course of the disease and the associated disability. Reversal reaction (type 1), erythema nodosum leprosum (type 2), and Lucio phenomenon are the 3 leprosy reactions, and they are most commonly seen in patients with the lepromatous and borderline categories of the disease. Because these forms of leprosy are the most common types seen in the United States, it is particularly important for physicians to be able to recognize and treat them. The reactions may occur before, during, or after treatment with multidrug therapy. Reversal reactions are the most common cause of nerve damage in leprosy, and erythema nodosum leprosum may also lead to neuritis. Although there have not been enough studies to confirm the most effective management regimens, treatment of reversal reaction and Lucio phenomenon with prednisone and of erythema nodosum leprosum with thalidomide and/or prednisone may help improve symptoms and prevent further disability.

Keywords: Hansen disease; Lucio phenomenon; erythema nodosum leprosum; leprosy; reversal reaction; type 1 reaction; type 2 reaction.

Publication types

  • Review

MeSH terms

  • Biopsy, Needle
  • Disability Evaluation
  • Disease Progression
  • Drug Therapy, Combination
  • Erythema Nodosum / drug therapy
  • Erythema Nodosum / etiology
  • Erythema Nodosum / immunology*
  • Erythema Nodosum / pathology
  • Humans
  • Immunohistochemistry
  • Immunologic Factors
  • Leprostatic Agents / therapeutic use*
  • Leprosy / complications
  • Leprosy / drug therapy
  • Leprosy / immunology*
  • Leprosy / pathology
  • Leprosy, Lepromatous / drug therapy
  • Leprosy, Lepromatous / etiology
  • Leprosy, Lepromatous / immunology*
  • Male
  • Necrosis
  • Prednisone / therapeutic use
  • Prognosis
  • Risk Assessment
  • Severity of Illness Index
  • Vasculitis / drug therapy
  • Vasculitis / etiology
  • Vasculitis / immunology


  • Immunologic Factors
  • Leprostatic Agents
  • Prednisone