Cutaneous Tuberculosis Manifestations Explained

Tuberculosis (TB) can present with various skin findings. Understanding these key manifestations is important for diagnosis.

Primary Cutaneous TB Signs

• Lupus vulgaris: This is a common and specific form of cutaneous TB, often appearing as reddish-brown plaques or nodules, typically on the face or neck. It represents direct inoculation or hematogenous spread of the TB bacteria to the skin.

Associated Skin Reactions in TB

• Erythema nodosum: Characterized by tender, red lumps, usually on the shins. While it can have many causes, erythema nodosum is a recognized reactive manifestation associated with underlying tuberculosis, particularly in certain populations.

Analysis of Other Options

• Erythema marginatum is typically associated with rheumatic fever.
• Phyctenular conjunctivitis is an eye condition linked to TB, not a skin manifestation. Erythema multiforme has diverse causes.
• Pyoderma gangrenosum is an ulcerative condition not primarily linked to TB. Dactylitis (inflammation of digits) can occur in TB bone disease but is less commonly cited as a direct cutaneous manifestation compared to lupus vulgaris.

Therefore, erythema nodosum and lupus vulgaris are significant cutaneous manifestations associated with tuberculosis.