Leprosy

Key points

• Leprosy is a granulomatous disease primarily affecting the peripheral nerves and skin. It is caused by Mycobacterium leprae. Features
• patches of hypopigmented skin typically affecting the buttocks, face, and extensor surfaces of limbs
• sensory loss The degree of cell mediated immunity determines the type of leprosy a patient will develop. Low degree of cell mediated immunity → lepromatous leprosy ('multibacillary')
• extensive skin involvement
• symmetrical nerve involvement High degree of cell mediated immunity → tuberculoid leprosy ('paucibacillary')