Leprosy

Question 1

Definition

Answer 1

a contagious disease that affects the skin, mucous membranes, and nerves, causing discoloration and lumps on the skin and, in severe cases, disfigurement and deformities. Caused by mycobacterium leprae

Question 2

Pathogenesis

Answer 2

• incubation for leprosy is long: 2-6 years (slow growing)
• the peripheral nerves and skin of the extremeties are most commonly involved (cooler conditions)

Question 3

Clinical features

Answer 3

• the skin lesions are hypopigemented, scaly, hairless, non-sweating and anesthetic.
• The affected nerves are thickened and may be tender.
• the face including the eyes, the gluteal region and the extremetis are the most frequently involvet sides

Typical pattern is:

• Tuberculoid leprosy-
  
  • ​patient has a single lesion with clearly demarcated edges, central healing and atropy.
  • The affected nerves are in the same area and may be present as a nerve palsy
• Lepromatous leprosy -
  
  • the skin is usually involved first with numerous lesions. There can be macules, papules, nodules or plaques.
  • The nasal tissue is often involved, initially giving rhinitis but fruther damage results in collapse of the nasal bridge
  • skin of the face becomes indurate - leonine appearance
  • nerve involvement later that tuberculoid
  • symmetrical glove and stokcing sensory neuropathy

Question 4

Investigations

Answer 4

• diagnsosi made clinically
• Acid-fast-bacillo can be seen in skin or nasal mucosal smears
• M leprae does not grow on artificial culture
• culture only possible on armadillio tail or mouse footpad tissue
• skin and nerve biopsys can histologically confirm a diangosis
• PCR can detect M leprae

Question 5

Treatment

Answer 5

• all cases treat with MDT cosisting of
  
  • dapsone, clofaximine - daily
  • rifampicin - monthly
• treatment course is 2 years or until AFBS are no longer detected
• drug therapy administer from specialitst centre