In simple words: This code indicates tuberculosis that affects the skin and the tissue beneath it. It covers different forms, like lupus vulgaris (skin sores, often on the face) and scrofuloderma (ulcers or draining sores, usually near infected lymph nodes). It's caused by a bacterial infection.

Tuberculosis of skin and subcutaneous tissue encompasses various forms of cutaneous tuberculosis, including lupus vulgaris, scrofuloderma, and erythema induratum.It arises from infection with Mycobacterium tuberculosis or, less commonly, Mycobacterium bovis.Transmission can occur through direct inoculation into the skin (e.g., injury), contiguous spread from underlying structures, or hematogenous dissemination. Lupus vulgaris presents as reddish-brown plaques, often on the face. Scrofuloderma manifests as ulcers or draining sinuses overlying infected lymph nodes. Erythema induratum involves painful, subcutaneous nodules, typically on the legs.

Example 1: A patient presents with a slow-healing ulcer on their neck with underlying lymphadenopathy.Biopsy and culture confirm Mycobacterium tuberculosis, consistent with scrofuloderma., A patient with a history of pulmonary tuberculosis develops reddish-brown plaques on their face.Skin biopsy reveals granulomas, and acid-fast bacilli are identified, indicating lupus vulgaris., A patient presents with painful, tender nodules on their lower legs.They have a positive tuberculin skin test and constitutional symptoms.Biopsy reveals caseating granulomas, suggestive of erythema induratum.

Documentation should include details of the lesion's appearance (size, location, characteristics), results of skin biopsies and cultures, and any relevant diagnostic tests, like tuberculin skin test or IGRAs.Clinical findings suggestive of systemic tuberculosis should also be documented, such as fever, weight loss, or cough.