Persistent Pyrexia of Unknown Origin and Deep Vein Thrombosis in a Patient with Sjögren’s Syndrome: A Case Report

Background: Sjögren’s Syndrome (SS) is a systemic autoimmune disorder primarily affecting the exocrine glands but often presenting with significant extraglandular manifestations, including systemic vasculitis, hematological abnormalities, and antiphospholipid syndrome (APS). Atypical presentations, such as pyrexia of unknown origin (PUO) or thrombotic events, can delay diagnosis. Case Presentation: We report a 57-year-old male with persistent fever, anemia, and leukocytosis. Initial blood cultures identified Pseudomonas aeruginosa, and antibiotic therapy resulted in temporary improvement. Persistent febrile episodes prompted further evaluation, revealing bilateral hilar lymphadenopathy on HRCT thorax and strong anti-SS-A (Ro-52) antibody positivity, confirming SS. Despite no classical sicca symptoms, systemic inflammation and autoimmune markers led to the diagnosis. One month later, the patient developed deep vein thrombosis (DVT), confirmed by Doppler ultrasound. Positive antiphospholipid antibodies and lupus anticoagulant established APS. The patient was managed with anticoagulation and hydroxychloroquine, achieving clinical stability. Conclusion: This case highlights the diagnostic challenges in atypical SS presentations, emphasizing the need for a high index of suspicion in PUO. Multidisciplinary management addressing systemic inflammation, thrombotic risks, and infections is essential to improving outcomes in SS patients with extraglandular manifestations.