It’s Not Always An Infection: Pyoderma Gangrenosum of the Urogenital Tract in Two Patients with Multiple Sclerosis Treated with Rituximab (1795)

Objective: To characterize extracutaneous PG, a rare complication among rituximab treated MS patients Background: Rituximab, a B-cell depleting therapy used in the treatment of Multiple Sclerosis (MS), has been associated with pyoderma gangrenosum (PG). PG is an inflammatory, ulcerative, skin disease of unclear etiology. Rare cases of extracutaneous PG causing vulvovaginal ulcerations have been described in rituximab treated patients with lymphoma. Design/Methods: Chart review of 184 rituximab treated patients between 2013 to 2019 Results: Case 1: 27-year-old with a 6 year history of MS, on rituximab (1000 mg × 2, 14 days apart every 6 months) for 3 years due to disease progression despite other disease modifying agents (DMTs). Patient presented with vaginal ulceration, discharge, and fever. Biopsy of the vaginal lesion revealed marked acute and chronic inflammation consistent with PG. MRI of the pelvis revealed a complex perianal fistula. She underwent bilateral salpingectomy, appendectomy, peritoneal abscess drainage; no infectious process was identified. Case 2: 25-year-old diagnosed with MS at age 16 on rituximab (1,000 mg every 6 months), for 7 years following disease progression on multiple other DMTs. He presented with urinary retention, diarrhea, and fever. An abscess of the gluteal fold with a fistula tract to pelvis was present. MRI revealed multiple abscesses in the pelvis, prostate, urethra, kidney & perinephric regions. Microbiology cultures were negative. Prostate biopsy revealed ulceration with marked acute inflammation and granulation formation. Discussion: The PG diagnosis for both cases was supported by the persistent fever, sterile neutrophilia and leukocytosis in the absence of an infectious agent and despite antibiotic and antifungal coverage. The diagnosis was further confirmed on biopsy and by the dramatic improvement following prednisone and five days of IVIG once this therapy was initiated. Conclusions: Extracutaneous PG can occur in MS patients on rituximab, involve multiple urogenital organs and responds to steroids and IVIG. Disclosure: Dr. Parrotta has nothing to disclose. Dr. Zhovtis Ryerson has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Dr. Zhovtis Ryerson has received personal compensation for serving on speaker bureau for Biogen, Teva, Genentech and advisory board for Biogen and Celgene. Dr. Zhovtis Ryerson has received research support from Biogen. Dr. Krupp has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Biogen, Everyday Health, Gerson Lehman, Novartis, RedHill Biopharma, Roche, Shire, and Sanofi-Aventis. Dr. Krupp has received royalty, license fees, or contractual rights payments from Biogen, Reata Pharma, AbbVie Pharmaceuticals, Amicus Therapeutics, SA Inventions, Finkhar Health, Janssen Pharmaceuticals, Eisai, IPSOS, Octapharma, Atara Biotherapeutics, Merck, Research Tech, and ERT Inc. Dr. Krupp has received research support from Biogen and Novartis.