Rituximab-induced serum sickness in immunobullous disorders: A case series.

Key Clinical Message: Rituximab-induced serum sickness (RISS) is a rare complication of Rituximab (RTX) in immunobullous disorders. Clinicians should be aware of the occurrence of serum sickness symptoms during RTX administration, and prompt initiation of corticosteroid therapy is crucial in these patients. Additionally, RISS may occur with subsequent RTX doses and patients should be counseled accordingly. Abstract: Rituximab (RTX) is a chimeric monoclonal anti-CD20 antibody which has gained approval for the treatment of various autoimmune and lymphoproliferative disorders. While RTX-induced minor reactions, including immediate infusion-related reactions, are common, serum sickness is rare. Limited data exist regarding rituximab-induced serum sickness (RISS) in pemphigus vulgaris (PV) and mucous membrane pemphigoid (MMP). We report two cases of RISS following RTX administration in PV and MMP patients. Both patients presented with typical symptoms of serum sickness after RTX infusion, necessitating drug cessation and corticosteroid therapy for resolution. RISS represents a rare complication of RTX therapy. Clinicians should maintain awareness of serum sickness presentations during and post-RTX administration.

Facial pyoderma gangrenosum associated with fallopian tube carcinosarcoma.

Pyoderma gangrenosum (PG) is a neutrophilic dermatosis associated with underlying disorders. The association between PG and solid organ tumors (SM), including gynecologic cancers, has been previously reported. Here, we report a case of a 61-year-old woman with pyoderma gangrenosum on the posterior auricular region associated with an underlying fallopian tube carcinosarcoma: a rare and aggressive gynecologic malignancy. The patient's ulcer responded favorably to treatment, and surgical resection of the tumor was performed. The patient was then referred for further cancer management. No new lesions or recurrences were found over the 18 months of routine follow-up.

Dermatomyositis-lupus overlap syndrome complicated with cardiomyopathy after SARS-CoV-2 infection: A new potential trigger for musculoskeletal autoimmune disease development.

COVID-19 should be considered as a new triggering factor for autoimmune disorders like DM-lupus overlap syndrome. We recommend that patients presenting with dermatomyositis during this pandemic be screened for COVID-19.