Autoimmune/Inflammatory Syndrome Induced by Hyaluronic Acid and Hyaluronidase.

Skin aging is a biological and chronological process characterized by progressive alterations in the extracellular matrix, including reduced hyaluronic acid (HA) content. HA dermal fillers are widely used for cosmetic purposes and are generally considered safe; however, immune-mediated complications, including autoimmune/inflammatory syndrome induced by adjuvants (ASIA), have been increasingly reported. We report the case of a 35-year-old White woman who underwent cosmetic lip augmentation with HA and subsequently developed multisystem manifestations consistent with ASIA. Due to persistent local and systemic symptoms, hyaluronidase was administered; however, her condition deteriorated, with progression to systemic involvement. Clinical features included sicca symptoms, Raynaud's phenomenon, and cognitive impairment with reduced concentration and memory, severe fatigue, and progressive cutaneous changes characterized by skin laxity and hyperextensibility, compatible with acquired cutis laxa. Despite treatment with high-dose corticosteroids, methotrexate, analgesics, and antidepressants, no significant clinical improvement was observed. This case highlights the potential for severe immune-mediated and connective tissue complications following exposure to HA and hyaluronidase. Awareness of ASIA and its atypical manifestations, including acquired cutis laxa, is essential for early recognition and appropriate management of patients undergoing cosmetic procedures.