Scrofuloderma
Scrofuloderma represents the direct extension of a tuberculosis (TB) infection from an underlying structure—most commonly a lymph node—to the overlying skin.
Clinical Presentation
- Initial Finding: A firm, painless, subcutaneous nodule or mass.
- Progression: The overlying skin becomes thin, violaceous (purple), and eventually breaks down to form draining sinuses and ulcers.
- Location: Most frequently found in the cervical region (neck), reflecting underlying tuberculous cervical lymphadenitis (“scrofula”).
Diagnostic & Management Pearls
| Aspect | Details |
|---|---|
| Diagnosis | Aspiration or biopsy of the node/sinus for AFB culture and PCR. PPD is almost universally strongly positive. |
| Treatment | Systemic multi-drug anti-tuberculous therapy is curative. |
High-Yield Exam Pearl:
- Mechanism: Unlike Lupus Vulgaris, which is hematogenous or inoculation-based, Scrofuloderma is a contiguous spread from underlying bone, joint, or lymph node TB.
- Scarring: Once healed, the lesions leave behind characteristic, irregular, puckered, or cord-like scars.