A rare case of multiple lupus vulgaris in a multifocal tuberculosis pediatric patient.

TLDR: The uncommonness of the skin involvement in TB infection should warn the clinicians to commit every possible examination to detect the TB involvement in other organs, especially in immunocompromised children with suspected skin lesions.

Abstract: Multifocal tuberculosis (TB) is rare. The risk of occurrence of multifocal TB is increasing in immunocompromised patients. Cutaneous entanglement in multifocal TB occurs more infrequently, and its association with multifocal TB is scarcely reported. The aim of this case report was to show a rare case of lupus vulgaris accompanied by multifocal skeletal TB (vertebrae and knee joint) in a 15-year-old girl. There were kyphosis and deformities seen on physical examination. Dermatological status showed an erythematous plaque on the cheek and an erythematous nodule on the index finger of the left hand. The additional examinations such as bacteriological, histopathological, and polymerase chain reaction (PCR) examinations supported the diagnosis of cutaneous TB. Radiographic and PCR examinations confirmed the diagnosis of multiple skeletal TB. Mycobacterium tuberculosis was obtained from GeneXpert® examination of the skin lesion on the right cheek and synovial fluid of the knee. Therefore, multifocal TB could be confirmed in this patient. The uncommonness of the skin involvement in TB infection should warn the clinicians to commit every possible examination to detect the TB involvement in other organs, especially in immunocompromised children with suspected skin lesions.