Leprosy

Leprosy (Hansen's disease) is a chronic bacterial infection that mainly affects the skin, nerves, and sometimes the eyes and respiratory tract. It is curable — and if caught early, completely preventable from causing disability. Despite being much less common than it once was, India still reports the largest number of new leprosy cases in the world each year, accounting for roughly 60% of new cases globally.

How it spreads

Through prolonged close contact with an untreated case, mainly via respiratory droplets. Leprosy is much less contagious than most people assume — most people exposed to the bacterium never develop disease, because healthy immune systems clear it. Casual contact (handshakes, eating together) does not spread leprosy.

Symptoms

Leprosy develops slowly — signs can appear months to years after exposure:

• Light- or dark-coloured patches on the skin that are numb or have reduced sensation (can't feel touch, temperature, or pain)
• Thickened nerves, usually felt just below the skin at the elbow, wrist, knee, or neck
• Weakness or loss of sensation in hands, feet, or face
• Drooping eyelid, difficulty closing the eye
• Painless sores or burns on hands or feet that the person didn't notice happening (because sensation was already reduced)

The earliest sign is usually a skin patch that is numb to touch. Any skin patch that has lost sensation should be evaluated for leprosy.

Diagnosis

Clinical examination — a trained clinician can usually diagnose leprosy from the skin patches and nerve signs. A simple sensation test is enough for many cases. A skin-slit smear or skin biopsy may be done to confirm.

Treatment

Leprosy is fully curable with a 6-12 month course of multi-drug therapy (MDT) — a combination of antibiotics, provided free of charge at government health facilities. Treatment becomes non-infectious to others within days of starting. Starting MDT early prevents the nerve damage that leads to disability.

The social stigma around leprosy still causes people to hide symptoms and delay treatment — resulting in avoidable disability. If you or someone you know has a skin patch that is numb, see a doctor. There is no shame in the diagnosis, and treatment works.