Tuberculosis verrucosa cutis is a form of –
**Core Concept**
Tuberculosis verrucosa cutis (TVC) is a rare form of cutaneous tuberculosis that presents as a chronic, localized, and usually painless skin lesion, typically resulting from inoculation of Mycobacterium tuberculosis through minor skin trauma, such as a cut or scratch.
**Why the Correct Answer is Right**
TVC is a form of tuberculid, which is a cutaneous manifestation of an underlying focus of tuberculosis. It is characterized by the formation of a verrucous plaque or nodule, often on the hands or feet, due to the body's immune response to the tubercle bacillus. The lesion may be accompanied by lymphadenopathy and may persist for months to years if left untreated.
**Why Each Wrong Option is Incorrect**
* **Option A:** Not applicable, as the correct answer is not listed.
* **Option B:** This option is incorrect because TVC is not a form of lupus vulgaris, which is a common form of cutaneous tuberculosis that presents as a chronic, progressive, and destructive skin lesion, often with a characteristic "butterfly" distribution on the face.
* **Option C:** This option is incorrect because TVC is not a form of erythema induratum, which is a type of tuberculid that presents as a painful, nodular lesion on the calves, often in association with systemic tuberculosis.
* **Option D:** This option is incorrect because TVC is not a form of scrofuloderma, which is a type of cutaneous tuberculosis that presents as a chronic, draining sinus or ulcer, often in association with underlying lymphadenopathy.
**Clinical Pearl / High-Yield Fact**
Tuberculosis verrucosa cutis is a rare but important form of cutaneous tuberculosis that should be considered in the differential diagnosis of chronic skin lesions, particularly in individuals with a history of minor skin trauma or exposure to tuberculosis.
**Correct Answer: C.**