Leprosy

Key facts

• Leprosy, also called Hansen's disease, is a chronic infection caused by Mycobacterium leprae, a slow-growing bacterium that mainly targets skin, peripheral nerves, and mucous membranes.
• It's curable, and transmission requires prolonged, close contact; casual contact doesn't spread it.
• Treatment is months to years of multi-drug antibiotic therapy; clofazimine is a core component of the regimen for the more severe multibacillary form.
• Early diagnosis matters most: numb or discoloured skin patches, thickened nerves, or weakness in the hands or feet should prompt medical review.

How treatment works

Because M. leprae grows so slowly, leprosy needs months to years of combination antibiotic therapy to prevent resistance and achieve a full cure. The standard regimen combines several antibiotics from different classes to clear the bacteria and limit the nerve damage that causes lasting disability. Clofazimine is a core part of the WHO-recommended regimen for the multibacillary, more severe, form; it has both antibacterial and anti-inflammatory effects that help control the painful immune reactions that can flare up during treatment.

Completing the full course matters. Stopping early risks relapse and further nerve damage, which is the main cause of permanent disability in cases that go untreated or undertreated.

Nerve damage and when to act

Early diagnosis is the single biggest factor in preventing disability. Warning signs include skin patches that are lighter or redder than the surrounding skin and have reduced sensation, thickened or tender peripheral nerves, and numbness or weakness in the hands or feet. Diagnosis is usually confirmed with a skin smear or biopsy looking for the bacterium under a microscope. Anyone who notices these features should seek medical review promptly; leprosy remains far more treatable, and far less likely to cause lasting nerve damage, the earlier it's caught.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.