Photodermatitis following knee intra-articular hylan G-F 20 injection for osteoarthritis: two cases.

Hyaluronic acid (HA) intra-articular injections are increasingly used for the treatment of knee osteoarthritis. Described adverse reactions of HA intra-articular injections include injection site pain or swelling. A 71-year-old man and a 65-year-old woman independently presented with photodistributed lesions shortly after receiving a repeat HA injection (hylan G-F 20) intra-articularly. A punch biopsy was performed which was consistent with a photodrug reaction or hypersensitivity reaction. Two cases are presented to describe a novel presentation of a photosensitivity reaction to HA.