Medical Awareness >>   Leprosy


Leprosy disease or Hansen’s disease is a chronic infectious disease caused due to Mycobacterium leprae, largely affecting the epidermis, mucosal coverings of the upper respiratory tract, peripheral nerves, and eyes. Leprosy can occur at any age, and it is curable, and treatment in the early stages can prevent disability. Leprosy is likely to be transmitted via air droplets, and can spread through the mouth and nose during close and constant contact with untreated cases. These are leprosy causes.  The risk factors associated with transmission are living in areas of poverty, close contact with leprosy people, genetic mutations etc. infection with HIV does not appear to increase the risk of developing leprosy. BCG vaccine offers a variable amount of prevention against leprosy and a novel vaccine called Lepvax, entered clinical trials in 2017, it also had encouraging results in 24 participants in trials. If it turns out to be successful in all people in India and abroad then it will be the first leprosy specific vaccine available.


Leprosy presents as three types-

  • Paucibacillary leprosy
  • Multibacillary leprosy
  • Borderline leprosy 

Paucibacillary leprosy

    Multibacillary leprosy

    Borderline leprosy 

Restricted pathogenic growth

Extensively spreads all over the body

A mix of tuberculoid and lepromatous leprosy

Relatively high cell mediated immunity

Poor cell mediated immunity


Less severe case of leprosy

Most severe stage


Does not involve high bacterial load

Involves high bacterial load


Incubation period 2-5 years

8-12 years



Some other uncommon presentations of leprosy are nerve enlargement, corneal ulcer, staphyloma, nose skin changes, saddle nose deformity, ear lesions, hands digit erosion, resorption of digits on hand. Reactive episodes of leprosy include type 1 reversal reactions, type 2 reactions called erythema nodosum leprosum and lucio’s phenomenon. 


Leprosy was once feared as a highly contagious disease but now it is known that its treatment is effective and people live an active life during and after treatment. But if leprosy is left untreated, it can cause severe nerve damage leading to crippling of hands, feet, paralysis and blindness. Symptoms affect skin, nerves and mucus membranes. This disease can cause skin symptoms such as discolored patches of skin, growth on skin, dry skin, and painless ulcers on soles of feet, lumps on face or earlobes, loss of eyebrows, numbness of nerves, muscle weakness, enlarged nerves, eye problems, nose bleeds, and blindness. Symptoms may occur within a year but can take as long as two decades or more. Clinical implications are clear to observe. Skin lesions normally have different pigmentation than normal skin and may have various aspects like flat, raised, or nodules. These can be singular or multiple and may exhibit a loss of sensation in the skin. Thus these are all signs and symptoms of leprosy


Leprosy Treatment-

Leprosy can be treated with multidrug therapy, as the cure of leprosy with only one anti-leprosy drug (monotherapy) will develop drug resistance to that drug. The blend of drugs used in multidrug therapy depends on the spread of the disease. A combination of drugs is given at the same time to treat. Multidrug therapy includes dapsone with rifampicin, and clofazimine. These are leprosy treatment drugs. Treatment usually lasts for one to two years. Although the treatment can cure the disease and prevent it from getting worse, it cannot reverse the nerve damage or physical disfiguration that may have occurred before the diagnosis. 

Differential Diagnosis-

DD of leprosy types are mostly skin lesions such as-

  • Granuloma annulare
  • Keloid
  • Systemic lupus erythematosus 
  • Fungal infection
  • Cutaneous leishmaniasis etc.,


Fact Sheet-

  • The prevalence rate of leprosy in India is 0.57/10,000 population as of March 2020.
  • Incubation period of lepra bacilli is 5 years.
  • In year 1981, WHO recommended the MDT or multidrug therapy
  • More than 16 million patients have been treated with MDT over the past 20 years.
  • WHO released a program called Towards Zero Leprosy- Global Leprosy Strategy 2021-2030
  • Pregnant mothers with leprosy can’t pass it to their unborn babies.
  • Leprosy is not transmitted by sexual contact. 
  • Paucibacillary leprosy is also called tuberculoid leprosy.
  • Multibacillary leprosy is also called lepromatous leprosy.
  • A complication of leprosy is erectile dysfunction and infertility in men.
  • Lepromin skin test is used to determine the form of leprosy in an individual along with physical examination and biopsy.
  • Leprosy can be prevented by avoiding long term close contact with a person who has an untreated infection.

PGC Resolution-

Control of existing cases, advancing the treatment and the elimination of leprosy in India.