Chronic interstitial cystitis as an initial major manifestation of systemic lupus erythematosus.

Chronic interstitial cystitis (CIC) has been thought to result from autoimmune phenomena and its occurrence in systemic lupus erythematosus (SLE) has occasionally been recorded. We report a patient with SLE whose initial urinary symptoms were caused by CIC. Two of 3 patients (including ours) whose cases have been reported also had diarrhea, a common symptom in idiopathic CIC. All 3 patients had cutaneous and/or bladder vasculitis. CIC occurring in SLE seems to be due to immune complex deposition.