Anaphylaxis and prolonged allergic reactions caused by intra-articular injection of diclofenac etalhyaluronate in knee osteoarthritis: A case report.

Osteoarthritis (OA) is a common condition. The treatment of knee OA aims to improve the quality of life and clinical symptoms, mainly knee pain. To develop a new treatment option, diclofenac etalhyaluronate (DF-HA;ONO-5704/SI-613; trade name: JOYCLU) was developed. Its anti-inflammatory and pain-relieving effects have been demonstrated. Conversely, adverse events have also been reported. Here, we report the case of a 71-year-old female who presented with anaphylaxis and prolonged allergic reactions after an intra-articular injection of JOYCLU. A basophil activation test (BAT) was performed to determine the cause of the anaphylaxis. BAT showed no positive findings. As the incidence of knee OA increases, the number of cases of JOYCLU use is expected to grow; therefore, careful administration is required. In this case, the cause was unknown by BAT. Thus, further development of appropriate testing methods is necessary. Intra-articular allergic reactions in knee OA may be modified and worsened besides normal allergic reactions; therefore, caution is required.