In simple words: Tuberculoid leprosy is a mild form of leprosy that affects the skin and nerves. It causes light-colored patches of skin with numbness and can sometimes cause enlarged nerves.It may go away on its own or develop into a more serious type of leprosy. Leprosy, in general, can cause skin changes, lumps, and nerve problems that can lead to numbness, weakness, and even loss of fingers or toes if left untreated.

Tuberculoid leprosy is a chronic granulomatous disease caused by Mycobacterium leprae. It primarily affects the skin and peripheral nerves, presenting with pale, flat, hypopigmented macules with loss of sensation.Enlarged peripheral nerves are also common. This form of leprosy may self-resolve or progress to other forms.Leprosy can also manifest as discolored skin patches, dry or thickened skin, disfiguring nodules (especially on the face and earlobes), painless foot ulcers, and loss of eyebrows or eyelashes.Severe or untreated cases can lead to numbness, loss of temperature and pain sensation, muscle weakness, paralysis, and even loss of digits or blindness.

Example 1: A patient presents with a single, well-defined hypopigmented macule on their arm with diminished sensation.Nerve thickening is noted in the area.Biopsy confirms Mycobacterium leprae, leading to a diagnosis of tuberculoid leprosy., A patient presents with multiple hypopigmented macules on their back and legs, some of which are anesthetic.They also report tingling and numbness in their hands and feet.Nerve conduction studies and biopsy confirm tuberculoid leprosy., A child presents with a pale, flat lesion on their face, which has been present for several months.The lesion is numb to touch.Slit-skin smear and biopsy confirm tuberculoid leprosy.

Documentation for A30.1 should include: detailed description of the skin lesions (size, number, location, sensory changes), evidence of nerve involvement (enlargement, sensory/motor deficits), results of diagnostic tests (biopsy, slit-skin smear), and response to treatment.

** Tuberculoid leprosy is classified according to the Ridley-Jopling classification.This system categorizes leprosy based on clinical, bacteriological, immunological, and histological features.Tuberculoid leprosy represents one end of the spectrum (TT), with lepromatous leprosy (LL) at the other end and borderline forms in between.