Track
Case ReportsAbstract
Background: Bacillus Calmette-Guérin (BCG) vaccination is a widely used strategy for the prevention of tuberculosis (TB), particularly in regions where the disease is endemic. While generally considered safe and effective, rare adverse events have been reported, including the development of lupus vulgaris, a chronic form of cutaneous tuberculosis. While histopathological examination remains the cornerstone of diagnosis, molecular techniques such as polymerase chain reaction (PCR) have emerged as valuable adjuncts for confirming Mycobacterium tuberculosis infection in tissue samples.Case: 7 years old Immunocompetent boy was presented with annular erythematous plaque with central healing and overlying crusty scales for several years. It started few months after BCG vaccination at birth. Skin biopsy revealed suppurative Granuloma. special stains non-contributory. T-spot test and tissue culture were negative. Tissue PCR showed Mycobacterium tuberculosis traces was detected.Comment: Tissue PCR has demonstrated high sensitivity and specificity in the diagnosis of lupus vulgaris, particularly in cases where conventional methods such as acid-fast bacilli (AFB) staining and culture are negative. Several studies have reported the successful application of tissue PCR in confirming the diagnosis of lupus vulgaris, leading to timely initiation of antitubercular therapy and improved patient outcomes.