Dr Dulcy Rakumakoe
5 minute read
13 Jun 2022
8:01 am

Leprosy: Biblical disease still around, and its symptoms can take up to 20 years to appear

Dr Dulcy Rakumakoe

What to look out for and when to see your doctor.

Picture: iStock

Leprosy is an infectious disease that causes severe skin sores and nerve damage in the arms, legs and skin areas around your body. Leprosy has been around for thousands of years and has affected many people across the world.

It is not a very contagious disease. You can catch it only if you come into close and repeated contact with nose and mouth droplets from someone with untreated leprosy.

Children are more likely to get leprosy than adults.

Today, more than 200 000 people worldwide are infected with leprosy, according to the World Health Organization – most of them in Africa and Asia.

Leprosy, a communicable disease caused by Mycobacterium leprae, is a notifiable medical condition in South Africa. Most of the cases occur in the eastern coastal areas and the south-eastern Highveld.

Although the prevalence of leprosy is low, about 4 000 people in South Africa need medical and social care. Hospitalisation is no longer recommended for leprosy patients as the emphasis is now on treatment in the community. New cases of leprosy are at risk of becoming disabled, especially if not diagnosed early or treated appropriately.

Causes

Leprosy is caused by a slow growing type of bacteria called Mycobacterium leprae (M. leprae). It isn’t clear exactly how leprosy is transmitted. When a person with leprosy coughs or sneezes, they may spread droplets containing the M. leprae bacteria that another person breathes in. Close physical contact with an infected person is necessary to transmit the disease. It isn’t spread by casual contact with an infected person, like shaking hands, hugging or sitting next to them on a bus or at a table during a meal.

Pregnant mothers with leprosy can’t pass it to their unborn babies. It’s not transmitted by sexual contact either.

Symptoms

Leprosy primarily affects your skin and nerves outside your brain and spinal cord. It may also strike your eyes and the thin tissue lining the inside of your nose. The main symptom of leprosy is disfiguring skin sores, lumps or bumps that don’t go away after several weeks or months.

The skin sores are pale-coloured. Nerve damage can lead to loss of feeling in the arms and legs. It usually takes about three to five years for symptoms to appear after coming into contact with the bacteria that causes leprosy.

Some people do not develop symptoms until 20 years later. The time between contact with the bacteria and the appearance of symptoms is called the incubation period.

Leprosy’s long incubation period makes it very difficult for doctors to determine when and where a person with leprosy got infected.

Forms of leprosy

Leprosy is defined by the number and type of skin sores you have. Specific symptoms and treatment depend on the type of leprosy.

The types are:

  • Tuberculoid. A mild, less severe form of leprosy. People with this type have only one or a few patches of flat, pale-coloured skin. The affected area of skin may feel numb because of nerve damage underneath. Tuberculoid leprosy is less contagious than other forms.
  • Lepromatous. A more severe form of the disease. It brings about widespread skin bumps and rashes (multibacillary leprosy), numbness and muscle weakness. The nose, kidneys and reproductive organs may also be affected. It is more contagious than tuberculoid leprosy.
  • Borderline. People with this type of leprosy have symptoms of both the tuberculoid and lepromatous forms.

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Diagnosis

If you have a skin sore that might be leprosy, the doctor will remove a small sample of it and send it to a lab to be examined. This is called a skin biopsy. Your doctor may also do a skin smear test. If you have paucibacillary leprosy there won’t be any bacteria in the test results.

If you have multibacillary leprosy, there will be. You may need a lepromin skin test to see which type of leprosy you have. For this test, the doctor will inject a small amount of inactive leprosy-causing bacteria just underneath the skin of your forearm. They will check the spot where you got the shot three days later and then again 28 days later, to see if you have a reaction.

If you do have a reaction, you may have tuberculoid or borderline tuberculoid leprosy. People who don’t have leprosy or who have lepromatous leprosy won’t have a reaction to this test.

Treatment

Leprosy can be cured. In the past two decades, 16 million people with leprosy have been cured. Treatment depends on the type of leprosy that you have. Antibiotics are used to treat the infection. Doctors recommend long-term treatment, usually for six months to a year. If you have severe leprosy, you may need to take antibiotics longer. Antibiotics can’t treat the nerve damage that comes with leprosy. Multidrug therapy (MDT) is a common treatment for leprosy that combines antibiotics.

That means you’ll take two or more antibiotics:

  • Paucibacillary leprosy: You’ll take two antibiotics, such as dapsone each day and rifampicin once a month.
  • Multibacillary leprosy: You’ll take a daily dose of the antibiotic clofazimine in addition to the daily dapsone and monthly rifampicin doses. You’ll take multidrug therapy for one to two years and then you’ll be cured.

Leprosy complications

Without treatment, leprosy can permanently damage your skin, nerves, arms, legs, feet and eyes.

Complications of leprosy can include:

  • Blindness or glaucoma
  • Iritis
  • Hair loss
  • Infertility
  • Disfiguration of the face (including permanent swelling, bumps, and lumps)
  • Erectile dysfunction and infertility
  • Kidney failure
  • Muscle weakness that leads to claw-like hands or not being able to flex your feet
  • Permanent damage to the inside of your nose, which can lead to nosebleeds and a chronic stuffy nose
  • Permanent damage to the nerves outside your brain and spinal cord, including those in the arms, legs and feet
  • Nerve damage can lead to a dangerous loss of feeling. If you have leprosy-related nerve damage, you may not feel pain when you get cuts, burns or other injuries on your hands, legs or feet.