Leprosy

Background

• Also known as Hansen's Disease
• Infectious disease caused by Mycobacterium leprae
• Most new cases found in developing countries
• Level 3 Countries with higher numbers of cases include: India, Brazil, Indonesia, Bangladesh, Nigeria
• Means of transmission not fully understood; likely respiratory.
• Has variety of clinical and histopathologic manifestations due to broad range of cellular immune response

Classification

• Disease spectrum ranges from strong immune reaction and few organisms (tuberculoid) to weak immune reaction and numerous organisms (lepromatous)
• Categories
  • Tuberculoid (TT)
  • Borderline tuberculoid (BT)
  • Mid-borderline (BB)
  • Borderline lepromatous (BL)
  • Lepromatous (LL)
  • Indeterminate (I)

Risk Factors

• Close contact
• Type of leprosy in the contact (lepromatous may be more contagious than tuberculoid)
• Armadillo exposure
• Increased age
• Genetic influences

Presentation

• Consider leprosy in patients who have skin lesions that do not respond to conventional treatments or when there are associated sensory disturbances

Differential Diagnosis

• Systemic lupus erythematosus
• Sarcoidosis
• Syphilis
• Erythema nodosum
• Erythema multiforme
• Cutaneous tuberculosis
• Vitiligo
• Scleroderma
• Tinea versicolor
• Mycosis fungoides
• Diffuse cutaneous leishmaniasis
• Neuropathy of other etiology

Manifestations

• Hypopigmented or red patches of skin
• Diminished sensation or lost sensation within patches
• Paresthesias
• Painless wounds on hands or feet
• Lumps on earlobes or face
• Tender, enlarged peripheral nerves

Work Up

• Diagnosis made by skin biopsy

Management

• The National Hansen's Disease Program recommends:
  • Tuberculoid: TT and BT
    • Treat for twelve months with both:
      • Dapsone 100mg daily + Rifampin 600mg daily
  • Lepromatous: LL, BL, BB
    • Treat for twenty-four months with all three:
      • Dapsone 100mg daily + Rifampin 600mg daily + Clofazimine 50mg daily
• Refer patient:

National Hansen’s Disease Programs 1770 Physicians Park Drive Baton Rouge, Louisiana 70816 1-800-642-2477 Http://www.hrsa.gov/hansensdisease/

Complications

• Immunologic reaction that can occur before or during treatment. Presentation can include: fatigue, malaise, fever, neuritis, arthritis, iritis, nasopharyngeal symptoms

Sources

• UpToDate
• Diagnosaurus
• National Hansen's Disease Program Http://www.hrsa.gov/hansensdisease/
• Wright SW, Jack M. Chapter 21. Tropical Medicine. In: Knoop KJ, Stack LB, Storrow AB, Thurman R. eds. The Atlas of Emergency Medicine, 3e. New York, NY: McGraw-Hill; 2010.
• http://www.ncbi.nlm.nih.gov/pubmed/10805626