Leprosy
Leprosy is also known as Hansen’s disease. It is an infectious disease that is caused by the bacteria Mycobacterium leprae. It commonly affects the mucous membranes, nerves, eyes, and skin. Leprosy lesions have disfigured sores that contain contagious fluid. This disease causes severe nerve damage.
Leprosy has been common in people since ancient times and exists to date. For years, the affected individuals were isolated from others due to a poor understanding of the disease. However, better treatment options are available today, and the need for quarantine is non-obligatory.
Leprosy affects people of all ages. However, it is more commonly seen in 5-15 years of age and those over 30. Even though leprosy is contagious, people contract it only after prolonged contact or contact with infected mouth droplets of untreated individuals. However, the exact mechanism of spread needs to be better understood. In addition, this disease affects children more commonly than adults.
The bacterium likely transmits through airborne droplets when an infected individual sneezes or coughs. Leprosy does not spread through direct skin-to-skin contact, such as hugging, shaking hands, sexual contact, or others. In addition, most people have a natural immunity to Mycobacterium leprae.
Types of Leprosy
Leprosy can be defined based on the number and type of skin sores present and based on its type, the symptoms and treatment differ. Following are the different types of leprosy:
Tuberculoid: It is also known as paucibacillary leprosy. It is a mild, less severe form of leprosy. Its symptoms include one or few patches of flat and pale-coloured skin. This condition damages the nerve, making the skin feel numb. This type is less contagious than the lepromatous form.
Lepromatous: This type is also known as multibacillary leprosy. It is a more severe type of disease. Widespread numbness, skin bumps, rashes, and weakness in the muscle characterise it. Other organs, such as the kidneys, nose, and male reproductive organs, may also be involved. It is more contagious than the tuberculoid type.
Borderline: People diagnosed with this type show symptoms of both tuberculoid and lepromatous types.
Symptoms of Hansen's disease
The primary symptoms of Hansen's disease or leprosy include:
Muscle weakness
Numbness in the hands, feet, arms and legs
Skin lesions.
Due to skin lesions, the nerves underneath are damaged, resulting in loss of sensation such as touch, temperature, or pain. These lesions remain unhealed for weeks and appear lighter than the skin tone. However, some lesions may appear red due to inflammation
Leprosy may also affect the brain, spinal cord, eyes and inner tissue lining of the nose.
Other symptoms include:
Disfiguring skin sores
Lumps or bumps that remain unhealed for several weeks or months
Painless wounds or burns that appear on the hands and feet
Thick or stiff skin
Nasal congestion
Nosebleeds
Enlarged peripheral nerves
Loss of eyelashes or eyebrows
Advanced stage of Leprosy shows the following symptoms:
Paralysis
Vision loss
Chronic ulcers at the bottom of the feet that don't heal.
Disfigurement of the nose
Permanent damage to the hands and feet
Shortening of the fingers and toes
The incubation period of Mycobacterium leprae bacteria is about three to five years. Moreover, in some cases, it may take up to two decades. It thus becomes difficult for healthcare providers to predict the onset of the disease.
Causes of Leprosy
Leprosy, or Hansen's disease, is caused by the Mycobacterium leprae. This condition is contagious and is known to spread through infected mucosal secretions coughed or sneezed by an infected individual.
However, the condition is not highly contagious. It does not spread through direct skin-to-skin contact, such as hugging, shaking hands, sexual contact, or others. In addition, most people have a natural immunity to Mycobacterium leprae.
This bacterium multiplies very slowly and has an incubation period of three to five years. In some patients, it may manifest after decades.
Risk factors for Leprosy
The most important risk factors for contracting leprosy are close contact with untreated and active multibacillary disease patients. Among those cases, the chances of spread are highest in people diagnosed with the subtype of lepromatous leprosy. This condition is an endemic disease. Some endemic regions for leprosy include Angola, Brazil, India, Kiribati, Madagascar, Mozambique, Nepal, the Central African Republic, the Democratic Republic of Congo, the Republic of Marshall Islands, the Federated States of Micronesia, and the United Republic of Tanzania.
Other risk factors include:
Age group between 5 and 15 as well as over 30
Genetic variants of the NOD2-mediated signalling pathway
Armadillo contact
Tattoos
Immunosuppression
Vertical transmission from the mother
Diagnosis of Leprosy
Healthcare providers first record medical history and any symptoms that the patient has been experiencing. Then, if they suspect Hansen's disease, they might advise a skin biopsy. This procedure requires a small sample of the suspected tissue and part of the healthy tissue for microscopic examination.
In addition, doctors may prescribe a skin smear test. The results for different forms of leprosy are as follows:
Paucibacillary leprosy: No bacteria in the sample.
Multibacillary leprosy: Bacteria are present.
A lepromin skin test may be performed to diagnose the type of leprosy. In this test, a small amount of inactive M. leprae is injected underneath the skin. At the end of three days and 28 days, the injected spot is looked for a reaction. People who show a positive reaction may have tuberculoid or borderline leprosy, while those with lepromatous leprosy or no leprosy will not react to the test.
Treatment
WHO developed a multidrug therapy to treat Hansen's disease. It is a combination of multiple antibiotics that kill the bacteria causing leprosy. These antibiotics include:
Dapsone (Aczone)
Rifampin (Rifadin)
Clofazimine (Lamprene)
Minocycline (Minocin)
Ofloxacin (Ocuflox)
Along with the above medications, anti-inflammatory drugs such as aspirin, prednisone or thalidomide are prescribed. The entire treatment lasts for more than one or two years.
Complications
Leprosy, if left untreated, can cause several complications. These include:
Permanent damage to the arms, legs, skin, nerves, feet, and eyes
Blindness or glaucoma
Iritis
Disfiguration of the face, such as swelling, bumps, and lumps
Erectile dysfunction
Infertility in men
Kidney failure
Hair loss
Infertility
Muscle weakness causing claw-like hands or difficulty in flexing feet
Permanent damage to the inner lining of the nose, causing nosebleeds and stuffy nose
Permanent nerve damage causes loss of sensation such as touch, pain or temperature
Prevention
To prevent contracting leprosy, one must avoid long-term and close contact with untreated leprosy patients.
What’s the long-term outlook?
The prognosis is better if your Leprosy doctor detects Hansen's disease initially before it worsens. Early intervention prevents the disease's progression, stops more tissue damage, and averts potentially dangerous health issues.
The diagnosis is often worse when the diagnosis is made later when the person has suffered considerable damage or handicap. To stop the disease from spreading to other people and to stop the body from suffering additional harm, appropriate treatment is still required.
Despite a successful course of antibiotics, there may still be long-term medical issues, but your doctor can work with you to give the right therapy to help you deal with and manage any lingering issues.
Review
Reviewed by Dr Vandana Boobna, Associate Director, Internal Medicine.
Know More