A Case Report of Unilateral Pleural Effusion in a Middle-aged Woman: A Rare Coexistence.

A 39-year-old woman with a 1-year history of seronegative arthritis was admitted for shortness of breath, left-sided chest pain, and joint pains. Upon physical examination, the tips of her right leg's fifth toe showed dry gangrene. Laboratory results revealed proteinuria and positivity for antinuclear antibody, ribonucleoprotein/Smith (RNP/Sm) antibody, Smith, and anti-double-strand deoxyribonucleic acid (DNA) antibody. The chest radiograph showed cardiomegaly, and computed tomography (CT) of the chest revealed pleural effusion. Initial pleural investigations revealed exudative pleurisy, low adenosine deaminase (ADA), and pleural effusion with cytology positive for lupus erythematosus (LE) cells. Rigid thoracoscopy revealed necrotic parietal pleura. Acid-fast bacillus (AFB) yielded positive results with Ziehl-Neelsen stains. Based on the above clinical, cytohistological, and serological findings, a coexistence of lupus pleuritis with tuberculous serositis (TS) was diagnosed in the background of systemic lupus erythematosus (SLE) with renal crisis. After 2 months of antitubercular therapy (ATT) with maintenance dose of steroids, following symptomatic improvement, pulse steroids and cyclophosphamide were initiated for SLE with renal crisis, and ATT was continued for 6 months. Postcompletion of ATT, the patient had complete resolution and was in remission of SLE.