Maladie Auto-immune ? En fait c'est la lèpre !

• Leprosy is an infectious disease which affects the skin and the nerves. It is coming back mainly through imported cases…despite having being forgotten for a long time. It is prevalent in India and these common manifestations is why dermatology is taught together with leprosy (as it is with syphilis in many countries). In other words, Hansen’s is so much a skin disease “pretender” as syphilis is !
• The authors from Hanoi, Vietnam report the following case:
  • 31 year old female
    • history of papules on the right ear and cheek for 9 years
    • a slit-skin smear at the time was negative for acid fast-bacillae (AFB, Mycobacterium Leprae)
    • Lesions at the time responded with methyprednisolone.
  • 6 months before presenting to the authors the patient experienced the appearance of painful erythematous plaques and nodules on the arms and legs.
    • methylprednisolone enabled recovery from the lesions
  • Then appearance of painful plaques red plaques and nodules neck armpits arm. This time the slit-skin smear was postive for AFB and a final diagnosis of borderline lepromatous leprosy.
  • The only problem is that in between, the patient was diagnosed as having Auto-immune disease:
    • the first time as systemic lupus erythematosus (no lab tests done)
    • the second time as sweet’s syndrome

• Liu and al. did a review of 80 cases of leprosy and showed that 53 of those had been diagnosed. The problem occurs most commonly for type 2 reversion reactions: erythema nodosum leprosum type 2 reaction. They are often considered as autoimmune skin diseases and treated with steroids.

Conclusion: before diagnosing erythema nodisum for example, consider the patient’s background if in a country where leprosy is not prevalent (imported case). In endemic areas, think of it on top of the differential diagnoses.

Contributors

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

Source of Information: Tranh MT – Borderline Lepromatous Leprosy mistaken for Auto Immune disease. 2014 (4) – 21st Regional Conference of Dermatology; Danang (Vietnam)