Late onset hypersensitivity reaction to hyaluronic acid dermal fillers manifesting as cutaneous and visceral angioedema

Abstract Introduction Hyaluronic acid fillers are gaining popularity all across the globe. Although this aesthetic treatment is considered relatively safe, or that most unwanted effects are related to technical faults of the injections or infections, hypersensitivity reactions are being reported in acute or delayed forms. We herein describe an unusual case of hypersensitivity reaction to hyaluronic acid dermal fillers of 12‐month latency, manifesting as cutaneous and visceral angioedema, and refractory to steroids, antihistamines and omalizumab. Aim We aim to raise awareness of delayed hypersensitivity reactions to hyaluronic acid fillers since patients often unaware due to the time lapse from the procedure. Patients/Method A 47‐year‐old female, presenting with cutaneous and visceral angioedema 12 months after uneventful injection of hyaluronic acid‐based dermal fillers. Results Angioedema was refractory to systemic steroids, antihistamines and omalizumab. Symptoms resolved miraculously after dissolving the fillers with hyaluronidase. Conclusion In almost all previously described cases of late‐onset response to hyaluronic acid dermal fillers, swelling was restricted to the treated area, was responsive to steroids or required no intervention at all. To our knowledge, this is an unusual case of hypersensitivity reaction to hyaluronic acid dermal fillers of 12‐month latency, manifesting as refractory cutaneous and visceral angioedema.