Leprosy | Anatomy2Medicine
Leprosy Causes

Leprosy

 

  • Mycobacterium leprae
      • Leprosy, called Hansen’s disease
      • Mycobacterium leprae is usually spread from person to person in nasal droplets (MCQ)
      • infectivity of M. leprae is low  (MCQ)
      • incubation period protracted
      • clinical disease may develop years or even decades after initial contact with the organism.
      • Leprosy is a chronic granulomatous condition of peripheral nerves and mucocutaneous tissues, particularly the nasal mucosa.
  • Tuberculoid leprosy
        • lesions occur as large maculae (spots) in cooler body tissues, such as
          • skin – especially the nose, outer ears, and testicles (MCQ)
          • in superficial nerve endings. (MCQ)
        • Neuritis leads to patches of anesthesia in the skin.
  • The lesions are heavily infiltrated by lymphocytes and giant and epithelioid cells
        • but caseation does not occur. (MCQ)
        • The patient mounts a strong cell-mediated immune response
  • develops delayed hypersensitivity, which can be shown by a skin test with lepromin  (MCQ)
        • There are few bacteria in the lesions (paucibacillary). (MCQ)
      • Lepromatous leprosy
        • course of is slow but progressive  (MCQ)
        • Large numbers of organisms are present in the lesions and reticuloendothelial system (multi- bacillary) (MCQ)
        • It results from a severely depressed immune system  (MCQ)
        • Lepromin test – negative  (MCQ)
        • No well-formed granulomas emerge. (MCQ)
  • Laboratory identification
      • M. leprae is an acid-fast bacillus  (MCQ)
      • It has not been successfully maintained in artificial culture
      • It can be grown in the footpads of mice and in the armadillo, which is a natural host and reservoir of the pathogen.
      • Laboratory diagnosis of lepromatous leprosy
        • organisms are numerous
        • acid-fast stains of specimens from nasal mucosa or other infected areas. (MCQ)
      • Laboratory diagnosis of tuberculoid leprosy
        • organisms are extremely rare
  • diagnosis depends on clinical findings and the histology of biopsy material. (MCQ)