BEYOND POSITIVE ANA: UNMASKING OCCULT TUBERCULOSIS IN A YOUNG ADULT WITH SYSTEMIC LUPUS ERYTHEMATOSUS PRESENTING AS PYREXIA OF UNKNOWN ORIGIN—A DIAGNOSTIC ODYSSEY

Abstract

Background: Pyrexia of unknown origin (PUO) is one of the more difficult clinical presentations due to the overlapping features of infectious, autoimmune and malignant conditions. The diagnosis is often complicated by the presence of systemic lupus erythematosus (SLE) and tuberculosis (TB) in affected areas where TB is endemic. The distinction between disease flare and occult infection is important as immunosuppressive therapy may worsen undiagnosed tuberculosis. Case Presentation: A 21-year-old male with persistent high-grade fever, constitutional symptoms, progressive cytopenias and recurrent hospitalizations. Initial tests included leukopenia, thrombocytopenia, positive antinuclear antibody (ANA), anti-double stranded DNA positivity, and hypocomplementemia, diagnosing systemic lupus erythematosus. Although the patient received corticosteroid treatment, fever continued and the patient later developed generalized seizures, acute pancreatitis, severe thrombocytopenia, hemophagocytic lymphohistiocytosis (HLH), fungal pneumonia, and respiratory failure which necessitated intensive care. Later extensive microbiological studies confirmed tuberculosis that required multidrug antitubercular therapy and fungal infection that required prolonged antifungal therapy. Treatment included pulse methylprednisolone, IVIG, broad-spectrum antimicrobials, antifungal therapy, antitubercular therapy, anticonvulsants and multi-disciplinary supportive care. During follow-up, the patient's laboratory parameters slowly returned to normal and the clinical situation was stable. Conclusion: This case illustrates the as the diagnosis of SLE is made, tuberculosis should not be overlooked because of persistent fever even when the diagnosis of SLE is confirmed. A favorable outcome was the result of early multidisciplinary evaluation, frequent microbiologic evaluations, and ongoing re-evaluation of the working diagnosis.