Successful Treatment of Refractory Pemphigus Vulgaris with Ultra-Low-Dose Rituximab in a High-Risk Patient: A Case Report.

Pemphigus vulgaris is a rare autoimmune blistering disease that causes painful erosions on the skin and mucous membranes. Standard treatments include corticosteroids, immunosuppressants, and rituximab. However, managing pemphigus vulgaris in elderly patients with comorbidities remains challenging. We report a 73‑year‑old male patient who had pemphigus vulgaris poorly controlled by glucocorticoids and a history of malignancy after surgical resection. He was then treated with add-on ultra‑low‑dose rituximab (100 mg) combined with methylprednisolone. The patient achieved complete clinical remission without significant adverse events. The response has been sustained during 6 months of follow‑up. Our case suggests that ultra‑low‑dose rituximab may be a safe and effective option for selected patients with refractory pemphigus vulgaris, particularly those with advanced age or cancer. Longer follow-up and further studies are needed to evaluate its long-term efficacy and safety.