A Rare Manifestation of Systemic Lupus Erythematosus: A Case of Lupus Cystitis in Puerto Rico.

Lupus cystitis is an uncommon, yet serious complication of systemic lupus erythematosus (SLE) marked by inflammation of the bladder and associated with significant urinary tract manifestations. The diagnosis of lupus cystitis can be very challenging as it often appears before the diagnosis of lupus has been established. This report presents the case of a 36-year-old male patient with a history of SLE admitted with gastrointestinal (GI) and urinary symptoms who was subsequently diagnosed with lupus cystitis and highlights the clinical presentation, diagnostic challenges, and management strategies in these patients. The diagnosis was confirmed through a combination of clinical examination and laboratory findings. Treatment with corticosteroids and immunosuppressive agents can lead to substantial improvement for which early diagnosis and recognition by primary care team providers in a hospital setting is pivotal as delayed diagnosis can result in significant morbidity. This report highlights the critical importance of considering lupus cystitis as a differential diagnosis in patients with systemic SLE patients presenting with urinary symptoms.