What is the treatment and management of Hansen's disease (leprosy)?

Treatment and Management of Hansen's Disease (Leprosy)

Hansen's disease requires multidrug therapy based on disease classification, with treatment durations of 12-24 months depending on the clinical form, and management of immunologic reactions is essential to prevent disability.

Disease Classification and Diagnosis

Hansen's disease (leprosy) is a chronic bacterial infection caused by Mycobacterium leprae that primarily affects the skin, peripheral nerves, and mucosa of the upper airway. Diagnosis is confirmed by:

• Demonstration of acid-fast bacilli in skin or dermal nerve from full-thickness skin biopsy 1
• Clinical presentation with characteristic skin lesions and thickened nerves
• Nerve biopsy for "pure neural leprosy" cases 2

Disease classification is essential for determining treatment:

1. Paucibacillary (Tuberculoid):

   • Few well-demarcated, hypopigmented, anesthetic skin lesions
   • Peripheral nerve swelling may occur
   • Limited bacterial load

2. Multibacillary (Lepromatous):

   • Multiple erythematous papules/nodules or infiltration of face, hands, feet
   • Bilateral and symmetrical distribution
   • High bacterial load

3. Borderline (Dimorphous):

   • Features of both tuberculoid and lepromatous forms

4. Indeterminate:

   • Early hypopigmented macules without developed features 1

Standard Treatment Regimens

Paucibacillary Leprosy:

• Duration: 6 months
• Regimen:
  • Dapsone 100 mg daily
  • Rifampin 600 mg monthly (supervised) 1

Multibacillary Leprosy:

• Duration: 12-24 months
• Regimen:
  • Dapsone 100 mg daily
  • Rifampin 600 mg monthly (supervised)
  • Clofazimine 50-100 mg daily 1

Dosing Considerations:

• Dapsone:

  • Adults: Start with 50-100 mg daily
  • Children: Correspondingly smaller doses
  • Titrate to minimum maintenance level 3

• Clofazimine:

  • Adults: 50-100 mg daily (maximum 100 mg daily)
  • Children: 2-3 mg/kg/day 1

Alternative Regimens

For patients with drug intolerance or resistance:

• RMM Regimen: Monthly rifampin, moxifloxacin, and minocycline

  • Well-tolerated with high completion rates
  • Avoids skin hyperpigmentation associated with clofazimine 4

• Other alternatives:

  • Linezolid (600 mg daily or twice daily)
  • Clarithromycin
  • Ofloxacin 5

Management of Immunologic Reactions

Immunologic reactions are common complications that can occur before, during, or after treatment and require prompt management to prevent nerve damage and disability 5.

Type 1 Reaction (Reversal Reaction):

• Presentation: Swelling of existing skin and nerve lesions
• Management:
  • Continue anti-leprosy treatment
  • Corticosteroids (prednisone/prednisolone) for severe reactions or neuritis
  • Analgesics
  • Surgical decompression of swollen nerve trunks if needed 3

Type 2 Reaction (Erythema Nodosum Leprosum):

• Presentation: Fever, tender erythematous skin nodules, malaise, neuritis
• Management:
  • Continue anti-leprosy treatment
  • Corticosteroids for severe cases
  • Thalidomide (with appropriate precautions)
  • Pentoxifylline or TNF inhibitors for refractory cases 3, 5

Silent Neuropathy:

• Functional nerve impairment without obvious symptoms
• Requires early recognition and prompt treatment with corticosteroids 2

Monitoring and Follow-up

• Regular clinical assessment for treatment response

• Monitoring for drug toxicity:

  • Dapsone: Complete blood count for hemolytic anemia, methemoglobinemia
  • Rifampin: Liver function tests
  • Clofazimine: Monthly ECGs when possible, especially when combined with other QTc-prolonging agents 1

• Skin smears and biopsies to assess bacterial clearance

• Neurological assessment to monitor nerve function

Prevention of Disability

• Early diagnosis is critical (median delay to diagnosis is 12 months in the US) 6
• Prompt treatment of reactions and neuropathy
• Patient education on self-care of insensitive hands, feet, and eyes
• Rehabilitation services for those with established disabilities

Common Pitfalls to Avoid

1. Delayed diagnosis: Consider Hansen's disease in patients with unexplained skin lesions and peripheral neuropathy, especially with history of residence in endemic areas 6

2. Inadequate treatment of reactions: Reactions can occur even after completion of antimicrobial therapy and require prompt management

3. Premature discontinuation of therapy: Complete the full course of treatment to prevent relapse

4. Insufficient monitoring: Regular follow-up is essential to detect reactions, drug side effects, and treatment response

5. Missing concurrent infections: Screen for co-infections before starting immunosuppressive therapy

Hansen's disease is curable with appropriate antimicrobial therapy, but early diagnosis and proper management of reactions are essential to prevent the long-term disability that has historically characterized this disease.