Psoriasiform Lupus Vulgaris: A Diagnostic Challenge

Cutaneous tuberculosis is a rare and often overlooked manifestation of tuberculosis, frequently leading to delays from onset to diagnosis. This case report describes the presentation of a 65-year-old male with an asymptomatic solitary plaque with silvery scales persisting for over five years, mimicking solitary plaque psoriasis. Despite intermittent treatment with a potent steroid and a combination of calcipotriol, the patient had only modest alleviation. A skin biopsy was performed, and the histology revealed caseating tuberculoid granulomas. Following treatment with an antituberculosis regimen, the lesion showed significant improvement. The case report highlights the diagnostic challenges of this uncommon entity and the importance of thorough evaluation of recurrent and persistent lesions, particularly in populations with a higher prevalence of tuberculosis. Further, it aims to provide valuable insight to healthcare providers on the atypical clinical presentations of lupus vulgaris mimicking common dermatoses.