Leprosy

1) Disease Description (Causes and Symptoms)

• Cause: Leprosy is caused by Mycobacterium leprae (the leprosy bacillus) or related species invading the skin, peripheral nerves, and upper respiratory tract mucosa. Infectivity is low, and transmission is presumed to occur mainly through prolonged close contact (such as nasal secretions).
• Pathophysiology: The leprosy bacillus invades Schwann cells of peripheral nerves, causing nerve fiber damage and demyelination. Depending on the degree of the host’s cell-mediated immune response, the lesions vary in form (localized lesions in forms with strong cell-mediated immunity and extensive multiple lesions in forms with weak cell-mediated immunity).
• Main symptoms:
  • Skin: Hypopigmented or erythematous painless (sensory loss) lesions, nodules, and extensive rashes
  • Nerves: Peripheral nerve enlargement (wrist and ankle areas), decreased sensation (loss of pain, temperature, and touch sensation), muscle weakness and paralysis, and muscle atrophy
  • Upper respiratory tract/nose: Nosebleeds, nasal congestion, crust formation, and nasal cartilage deformity (saddle nose)
  • Eyes: Redness due to conjunctival and corneal involvement, corneal ulcers, cataracts, glaucoma, and decreased vision
  • Systemic: Fever and systemic symptoms are uncommon
• Incubation period: Very long, ranging from several months to years (even decades).

2) Treatment Methods (Standard Treatment · Procedures/Surgery · Lifestyle Management · Precautions)

• Standard drug treatment (WHO-recommended multidrug therapy, MDT):
  • Paucibacillary (POOR/PAUCI-BACTERIAL, PB): Multidrug therapy (primarily rifampicin + dapsone) for 6 months
  • Multibacillary (MULTI-BACTERIAL, MB): Multidrug therapy including rifampicin + dapsone + clofazimine for 12 months (or longer based on the clinician’s judgment)
  • The exact dosage and treatment duration are determined according to the patient classification (number of lesions, slit-skin smear results, etc.), so consultation with the treating physician is necessary
• Reaction treatment:
  • If a reversal reaction (type 1) or ENL (erythema nodosum leprosum, type 2) occurs, corticosteroids (used for neuritis and swelling) may be used; for ENL, steroids, clofazimine, thalidomide (restricted use in men or nonpregnant women), and other treatments may be used
• Surgery and rehabilitation:
  • Surgery to relieve nerve compression, corrective surgery for deformities, and plastic-surgical treatment for skin and soft-tissue damage
  • Physical and occupational therapy to preserve muscle strength and function, along with education to prevent pressure sores and trauma
• Monitoring and tests:
  • Liver function tests and blood tests before, during, and after treatment; in particular, consideration of the risk of hemolysis caused by dapsone (anemia and G6PD testing), and review of drug interactions
• Lifestyle management and precautions:
  • Infectivity decreases relatively quickly after treatment begins. However, there remains a risk of transmission through prolonged close contact with untreated patients.
  • Dapsone: Risk of hemolytic anemia (especially in people with G6PD deficiency); clofazimine: skin pigmentation (brown); rifampicin: hepatotoxicity and drug interactions (including with contraceptives).
  • Prevent injuries to areas with loss of skin sensation (using protective equipment and appropriate footwear) and treat wounds immediately. Early ophthalmologic evaluation is essential in the event of eye damage.
  • Support is needed for mental health problems caused by social stigma.

3) Checkpoints Before an Outpatient Visit (Including Preparation Materials and Example Questions)

• Preparation materials/data:
  • A list of all medications and supplements currently being taken (including dosage and frequency)
  • Previous diagnosis and treatment history (whether leprosy was diagnosed and the duration of previous antibiotic treatment)
  • Recent blood test and liver function test results (if available)
  • G6PD test results (if possible)
  • The onset and progression of skin lesions and nerve symptoms (decreased sensation, numbness, and muscle weakness), along with photographs (photos of visible lesions)
  • A list of household members and recent close contacts (if there are cohabitants)
• Symptom checklist:
  • When the symptoms began and whether they started in one area or multiple areas
  • The location and extent of numbness (loss of sensation), and whether tingling or pain is present
  • Eye dryness, pain, or changes in vision, and whether nosebleeds are present
• Tests that may be requested during the visit:
  • Skin biopsy (tissue examination), slit-skin smear (to check for bacilli), nerve conduction study (if necessary), blood tests (liver enzymes and CBC), and G6PD testing (before dapsone)
• Example questions to organize before the visit:
  • When the symptoms began, factors that worsen or improve them, and current priority concerns

4) Examples of General Questions to Ask the Doctor

• What is the expected treatment duration for this medication (or combination of medications)?
• What are the medication’s main side effects, and how should they be managed if they occur?
• How quickly does infectivity disappear after treatment begins? Do family members or cohabitants need testing?
• Which tests (such as liver function tests and blood tests) need to be monitored during treatment, and how often?
• What additional treatments or rehabilitation are available to prevent nerve damage (decreased sensation and paralysis)?

5) Examples of Condition-Specific Questions

• What measures should be taken quickly to prevent my nerve damage (e.g., numbness in the fingers and decreased muscle strength) from progressing?
• Do my family members (cohabitants) need screening (clinical examination and skin examination)? If so, which tests are needed and how often should they be performed? -(Optional) Is it safe to receive treatment during pregnancy? What is the safety of the medications during breastfeeding?

Note: This information is for reference only. An individual’s exact diagnosis and treatment plan are determined based on evaluation by the treating physician and test results.