Leprosy (Hansen's disease): Everything You Need to Know

Leprosy is a persistent bacterial infection that damages the skin, nerves, eyes, and respiratory tract, leading to serious health impairments. Untreated, it causes muscle weakness, permanent nerve damage, and loss of sensation. The disease affects infants to the elderly and is prevalent in tropical and subtropical regions worldwide. Two forms exist—one milder and one, the lepromatic form, that is notably severe and highly contagious.

Leprosy arises from a slow-growing, rod-shaped bacterium called myobacterium leprie. Its presence triggers the formation of large lumps and bumps on the body, clearly marking the infection. The bacterium’s action results in distinct physical symptoms that define the disease.

The mode of transmission remains uncertain but is thought to involve airborne droplets from coughs and sneezes of untreated individuals. Contracting the disease requires long-term, close exposure rather than brief, casual contact. There is no risk from sexual contact, casual physical interaction, or maternal-fetal transmission. Additionally, weakened immune systems and possible genetic predispositions elevate susceptibility.

Leprosy develops over an incubation period that can range from six months to twenty years, with genetic susceptibility significantly influencing its onset. Early manifestations include pale or pink skin patches, ulcers on the soles of the feet, and swelling or lumps around the face and earlobes, accompanied by nasal congestion and nosebleeds. Progressive nerve damage results in numbness, muscle weakness, and visibly enlarged nerves near the elbows and knees, which impair pain detection. The loss of sensation often leads to unnoticed burns and injuries, culminating in deformities such as lost extremities, blindness, and disfigurement if left untreated.

Leprosy can trigger the reabsorption of cartilage by the body. Diagnosis is primarily based on the clear visual recognition of symptoms. Laboratory tests are rarely required, ensuring that treatment is promptly guided by observable clinical signs.

Timely diagnosis of leprosy prevents debilitating effects and facilitates successful treatment. A combination of antibiotics including dapsone, rifampicin, and clefazamine is administered over 6 to 12 months. This multi-drug approach efficiently neutralizes the bacterium, emphasizing the importance of prompt intervention.