Behçet's disease and tuberculosis: unmasking infection behind a suspected flare.

Behçet's disease (BD) is a chronic and multisystem disorder characterized by recurrent oral and genital ulcers, along with ocular, cutaneous, vascular, gastrointestinal, and neurologic manifestations. The etiology is thought to involve an autoimmune response triggered by infectious or environmental factors in genetically predisposed individuals. Mycobacterium tuberculosis has been proposed as a potential trigger for BD, although this association remains rarely reported. We show a compelling case of a patient with BD diagnostic criteria who subsequently developed mediastinal tuberculous lymphadenitis, which was initially suspected as disease activity. This case underscores the importance of considering tuberculosis in BD patients with new or worsening symptoms despite appropriate therapy.