Application of 35 kDa Hyaluronic Acid Fragment in Managing Persistent Localized Pain in Rheumatoid Arthritis : A Case Report.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic joint inflammation, leading to joint damage and pain. This case report presents a 58-year-old Chinese female who developed widespread joint pain after contracting mild COVID-19 and was subsequently diagnosed with RA. Her symptoms included joint swelling, pain, and abnormal serological markers. Initial treatment with methylprednisolone and tofacitinib was discontinued due to side effects, and she switched to a combined approach of herbal and Western medicine. After a year of treatment, her widespread pain and joint swelling largely resolved, leaving persistent localized pain in specific joints. To address this persistent localized pain, she received 35 kDa hyaluronan fragment (HA35) injections, resulting in significant improvement, including complete relief of elbow and knee pain and restored joint mobility. Continuous HA35 injections, followed by oral HA35 powder, also completely relieved her foot pain. This case highlights the effectiveness of HA35 in managing persistent RA pain, particularly for residual pain after conventional treatments, and suggests its potential as a therapeutic option.