Cutaneous tuberculosis is a rare form of extrapulmonary tuberculosis seen in 1% of all cases. Lupus vulgaris is one of the most common types of cutaneous tuberculosis. Its cutaneous patterns may mimic other dermatologic conditions such as pyoderma gangrenosum. Clinical, diagnostics and histopathologic correlation is important in diagnosing lupus vulgaris.

This is a case of a 17-year-old Filipino male with multi-drug resistant Pulmonary Tuberculosis who presented with three-months history of erythematous papule that gradually progressed into plaque on the scalp, abdomen and left popliteal area with associated pruritus 5/10. The initial working diagnosis was cutaneous tuberculosis versus pyoderma gangrenosum. Incision biopsy revealed a granulomatous dermatitis surrounded by a dense mixed cell infiltrate of lymphohistiocytes from superficial to mid dermis suggestive of an infectious process. Chest radiograph confirmed pulmonary tuberculosis, interferon gamma detection by enzyme linked immunosorbent assay (Quantiferon TB Gold Plus) and nucleic acid amplification test (GeneXpert TB) further verified the presence of Mycobacterium tuberculosis (MTB). The patient was managed as lupus vulgaris, plaque type and started on second line anti-Koch’s medications. Excellent clinical response was seen after 3 months of treatment.

Lupus vulgaris is a challenging disease and may mimic a myriad of other cutaneous disorders, in this case pyoderma gangrenosum. This case highlights a high index of suspicion, trained clinical eye and multi-specialty care to diagnose and treat complicated cutaneous tuberculosis cases. In geographic locations where MTB is still endemic and drug resistance burdens pose complications in treatment, second line pharmacologic interventions for MTB treatment is a viable option.