Unveiling the Hidden Dangers: Massive Allergic Dermatitis After Hyaluronic Acid Injection

The increasing use of hyaluronic acid (HA) implants has made adverse effects more apparent. Here, we present a rare case of massive allergic dermatitis due to HA injections. We performed dermoscopy and color ultrasound, which clarified that this was an allergic dermatitis caused by fillers, and analyzed the possible causes of the allergy. Common treatments were compared, and the advantages of 5-FU-based treatment regimens and their associated mechanisms were noted. A low dose of 5-fluorouracil and triamcinolone acetonide was administered to the patient's entire face and neck, and significant efficacy was achieved. We aimed to gather evidence on extensive dermatitis caused by HA injection, provide new perspectives and solutions for subsequent HA injections, and promote further research on the potential mechanisms of extensive skin inflammation and allergies caused by local HA injections.