Multiple lupus vulgaris

A 65-year-old female presented with a 10-year history of skin lesions over her face (Figure 1a). The lesions started as several 1 mm-sized asymptomatic, red-brown papules on the left side of the face, then similar lesions appeared over the forehead, right jaw, and back (Figure 1a–c) and expanded in the course of the disease. The patient experienced itching during the illness and scratched the lesions. At the local hospital, the patient was given topical and systemic antibiotic treatment intermittently, however, no significant improvement was noted. Dermatological examination revealed large, erythematous plaques on the left side of her face and forehead (Figure 1a,b). The surface of these plaques was mildly scaly with areas of atrophy and depigmentation in the center. Smaller erythematous plaques were noted on the right jaw and back (Figure 1c). Histopathological examination demonstrated epidermal hyperplasia, liquefaction, and degeneration of basal cells. Diffuse tuberculosis-like granulomas with multinucleated giant cell and lymphocyte infiltration were observed in the dermis (Figure 1d). Laboratory tests indicated low positivity for tubercular antibodies, but all other test results, including acid-fast staining, periodic acid schiff (PAS), immunological function tests, and lymphocyte subgroup examination, revealed no abnormalities. The patient was diagnosed with multiple lupus vulgaris. Lupus vulgaris is caused by the invasion of Mycobacterium tuberculosis on the skin.1 It is typically confined to one site; however, multiple skin lesions may be associated with scratch vaccination. Clinically, lupus vulgaris is often misdiagnosed as psoriasis, lichen simplex chronicus, erythema anulare centrifugum, or chronic discoid lupus erythematos.2 Despite the presence of Mycobacterium tuberculosis in the lesion, acid-fast staining often yields negative results, and not all biopsies reveal tuberculosis granuloma. For cases where diagnosis through histopathology remains uncertain, polymerase chain reaction analysis and a 6-week therapeutic trial are recommended, especially in endemic regions.3-5 None declared.