Systemic Lupus Erythematosus Vasculitis Causing Perforation Peritonitis in Miliary Tuberculosis: A Disease in Disguise.

Systemic lupus erythematosus is a complex disease to manage and is complicated further by coexisting comorbidities. We present the case of a 25-year-old female patient who arrived at the emergency department with complaints of abdominal pain for three days, accompanied by a history of fever and non-bilious vomiting for two days. She had no history of trauma or chronic use of painkillers. She was diagnosed with pulmonary and abdominal tuberculosis (TB) four months previously and has been on anti-tubercular therapy since then. Radiological studies showed a collection with echogenic foci in the right iliac fossa with features of abdominal tuberculosis and pneumoperitoneum likely due to perforation. An emergency laparotomy with end ileostomy and distal mucus fistula was performed, followed by limited ileocecal resection, and the specimen was sent for histopathological examination. Surprisingly, the histopathology study revealed SLE vasculitis, contrary to the initial suspicion of ileocecal TB as the cause of perforation peritonitis. The patient was discharged and was followed up within a week with normal stomal function.