Peritoneal vasculitis is a rare and severe clinical manifestation of systemic lupus erythematosus. We report a patient who presented with ascites due to peritoneal vasculitis and cutaneous, articular, hematological, and renal inflammatory activity. Treatment with glucocorticoids and immunosuppressive drugs was ineffective. In view of the resistance to different therapies, 4 weekly infusions of 375mg/m2 of rituximab (RTX) were started, in association with cyclophosphamide pulses during the first and the third weeks. With this treatment strategy, the patient reached a complete response which was achieved in later flares of inflammatory activity (the second and third flares were multisystemic and with ascites again, and the fourth flare with nephritis).

La vasculitis peritoneal es una manifestación clínica infrecuente y grave del lupus eritematoso sistémico. Se presenta el caso de una paciente con ascitis por vasculitis peritoneal y afección cutánea, articular, hemática y renal. El tratamiento con glucocorticoides e inmunosupresores resultó ineficaz para el control de la ascitis. Dada la resistencia al tratamiento convencional, se administró rituximab en cuatro infusiones semanales de 375mg/m2, potenciado con pulsos de ciclofosfamida las semanas 1 y 3. Con esta estrategia se consiguió una respuesta completa, que se repitió en brotes posteriores (el segundo y el tercero, multisistémicos y de nuevo con ascitis significativa, y el cuarto con nefritis).