A 40-year-old woman presents with a warty plaque over the right knee for 3 years. The plaque has a central atrophic scar with active verrucous borders. Biopsy shows caseating granulomas with Langhans giant cells. Mantoux test is strongly positive. What is the diagnosis?

• A Lupus vulgaris
• B Scrofuloderma
• C Lichen scrofulosorum
• D Tuberculosis verrucosa cutis ✓

Explanation

Tuberculosis verrucosa cutis (TVC) is a paucibacillary form of cutaneous TB occurring in individuals with moderate to strong immunity who are reinfected exogenously. It presents as a warty plaque, often on exposed sites like the knee, with active verrucous borders and central scarring, a pattern described as the 'warty tuberculosis.' Lupus vulgaris shows apple-jelly nodules on diascopy, and scrofuloderma arises from direct extension over infected lymph nodes.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.