-Dr.Nitin S Walia, DNB (Dermatology), MD – Dermatology, Venereology & Leprosy, MBBS Dermatologist, Delhi
Leprosy, also called Hansen’s disease, is a chronic bacterial infection primarily affecting the skin and peripheral nerves caused by Mycobacterium leprae. Leprosy can affect people of all races anywhere in the world. However, it is most common in warm, wet areas of the tropics and subtropics.
Although the global prevalence of leprosy has decreased significantly over the past 30 years-the worldwide prevalence is reported to be around 5.5 million, with 80% of these cases found in 5 countries: India, Indonesia, Myanmar, Brazil, and Nigeria.
Though Leprosy is contagious–prolonged, close contact with someone with untreated leprosy over many months is needed to catch the disease.
One cannot get leprosy from a casual leprosy contact like shaking hands or hugging, sitting next to each other or sitting together at a meal. Leprosy is also not passed on from a mother to her unborn baby during pregnancy and it is also not spread through sexual contact.
To confirm the diagnosis, the doctor may take a sample of skin or nerve (through a skin/nerve biopsy) to look for the bacteria under the microscope and may also do tests to rule out other skin diseases.
Leprosy is curable and treatment in the early stages can prevent disability. The form the disease takes depends on the person’s immune response to the infection and range over a spectrum from multibacillary lepromatous leprosy (LL) showing limited or low immunity to Mycobacterium lepromatosis, to paucibacillary tuberculoid leprosy (TT) with a strong immune response. In most patients, the first symptom noticed is numbness.
The initial skin lesions are usually a solitary or small number of hypopigmented patches before evolving. Usually, the affected skin changes colour and either become: lighter or darker, dry or flaky, with loss of feeling or reddish due to skin inflammation. Mycobacterium leprae bacteria attack the nerves, which can become swollen under the skin. . This can cause the affected areas to lose the ability to sense touch and pain, which can lead to injuries, like cuts and burns. If left untreated, the nerve damage can result in paralysis of hands and feet.
In very advanced cases, the person may have multiple injuries due to lack of sensation, and eventually, the body may reabsorb the affected digits over time, resulting in the apparent loss of toes and fingers. Corneal ulcers and blindness can also occur if facial nerves are affected.
Other signs of advanced Hansen’s disease may include loss of eyebrows and saddle-nose deformity resulting from damage to the nasal septum. Surgery may sometimes be used to drain abscesses to restore nerve function, reconstruct the collapsed nose, or to improve function or appearance of affected areas.
Antibiotics used during the treatment will kill the bacteria that cause leprosy. Treatment usually lasts between 1-2 years. Patient education is paramount. Once treatment is started, the person is no longer contagious.
Leprosy can be cured but it is essential to take the full course of medication. People with leprosy can continue to work and lead an active life during and after treatment. But while the treatment can cure the disease and prevent it from getting worse, it does not reverse nerve damage or physical disfiguration that may have occurred before the diagnosis.
Thus, it is very important that the disease be diagnosed as early as possible before any permanent nerve damage occurs. Patients should be instructed how to deal with existing nerve damage for example protecting numb feet from injury. Physical, social and psychological rehabilitation is necessary for those in whom the neglected disease has caused havoc.