What is Hansen’s disease?

  • -It is an infection caused by a bacteria called Mycobacterium Leprae.



How is it transmitted?

  • -This is still incompletely understood but it would be airborne.
  • -It is not transmitted during birth and even prolonged contact does not guarantee transmission.



How is it diagnosed?

  • -Examination of a skin biopsy is the most reliable and based on clinical suspicion.
  • -Lepromin tests are helpful to classify the type of leprosy but not to confirm the diagnosis.



What does it look like on the skin?

The disease is classified according to the immunity of the infected person:

  1. a. Tuberculoid (Paucibacillary)(maintained host immunity): lesions tend to be depigmented, few in number with an impaired sensation.

Tuberculoid Leprosy (Hansen)



  1. b. Lepromatous (Multibacillary)(depressed host immunity): lesions tend to be more voluminous, many in number and the face can be infiltrated (leonine facies).

Lepromatous Leprosy (Hansen)



  1. c. Borderline: lesions less specific in between the Tuberculoid and Borderline types.

Borderline Leprosy (Hansen)



Immunological reactions: sometimes the lesions do not contain the bacilli and are due to the immunity developed by the infected person: erythema nodosum leprosum,  reversion reactions (increased inflammation because of effective treatment, stress, pregnancy…)



Are other organs affected?

The nervous system and eyes are the most commonly affected:

  1. -Facial palsy
  2. -Blindness
  3. -Claw-hands
  4. -Foot-drop

Lower limbs are sometimes amputated due to prolonged bone resorption (osteomyelitis) and skin cancers developing on prolonged ulcers.




How is it treated?

  • -Treatment regimens vary from country to country.
  • -Antituberculous drugs, Dapsone and other antibiotics are used. Treatment must be continued for several months or years depending on the type of leprosy.
  • -Steroids and other anti-inflammatory drugs are used in immunological reactions.