Delayed hypersensitivity reaction to hyaluronic acid dermal filler following influenza-like illness.

Delayed reactions after facial hyaluronic acid injection are relatively rare complications. Their cause may be infectious or immune-mediated in origin, and their outbreak can be triggered, for example, by an influenza-like illness. To describe potential adverse event of influenza like illness following dermal filler injection. We report fourteen unusual cases of delayed hypersensitivity reaction to several brands of hyaluronic acid dermal filler following influenza like illness. Increasing evidence implicates influenza infection in the pathogenesis of late onset filler reaction. Although there is a low risk of late onset adverse reaction with hyaluronic acid fillers, injecting physicians must be aware of the possible filler reaction following the influenza infection.