Diagnostic dilemma in a patient with chronic non–healing ulcer on leg

Rationale: Though cutaneous tuberculosis accounts for a small proportion of all tuberculosis cases, it becomes an important health issue considering its high prevalence in tropical countries. Due to its myriad clinical manifestations, it becomes difficult to diagnose and may pose a great diagnostic dilemma. Patient concerns: A 17-year-old male complaint of ulcerproliferative lesion on the left lower leg for 5 years. There was no history suggestive of tuberculosis. On cutaneous examination, single well-defined erosiocrustive plaque of size 14 cm × 13 cm with yellowish adherent crust presented over the left lower leg. The underlying surface shows ulceration after removing the crust. Diagnosis: Ulcerative Lupus vulgaris. Interventions: Anti-tubercular drug therapy (isoniazid, rifampicin, pyrazinamide and ethambutol). Outcomes: Lesion showed dramatic improvement after one month of anti-tubercular therapy. Lessons: Dermatologists should be aware of variable clinical presentations of cutaneous tuberculosis so as to diagnose it timely and correctly.