: A chronic, progressive form often appearing on the face as reddish-brown "apple-jelly" nodules that can lead to significant scarring.
: Occurs when bacteria enter the skin directly through a cut or abrasion. The most common form is Tuberculosis Verrucosa Cutis , often seen on the hands of laboratory workers or physicians ("prosector’s wart").
Diagnosing cutaneous TB is notoriously difficult because its lesions can mimic other skin conditions like sarcoidosis or leprosy. Tuberculosis Overview - StatPearls - NCBI Bookshelf
: Bacteria travel through the blood to the skin, often in immunocompromised individuals. This can manifest as Acute Miliary Tuberculosis of the skin .
Because the appearance of cutaneous tuberculosis varies based on the patient's immune response and the method of infection, it is categorized into several forms:
: These are skin eruptions (like Erythema Induratum ) caused by a hypersensitivity reaction to the bacteria rather than the presence of live bacteria in the skin itself. Diagnosis and Challenges
: The most common form, typically occurring when an infected lymph node or bone breaks through the skin surface, creating ulcers and sinus tracts.