Abstract
Recombinant humanized type III collagen is widely used in facial rejuvenation due to its excellent biocompatibility and overall favorable safety profile; however, severe systemic hypersensitivity reactions are exceedingly rare. We report a case of a 47-year-old woman with no prior history of allergy who received topical lidocaine to the face, followed by injection of recombinant humanized type III collagen lyophilized fibers for skin texture improvement. Immediately after the injection, she developed suspectedly severe anaphylactic shock temporally associated with the recombinant collagen injectionpresenting with confusion, respiratory distress, followed by marked bradycardia (33 beats/min), and loss of palpable arterial pulse. Emergency protocols were activated immediately, including cardiopulmonary resuscitation, intravenous adrenaline, corticosteroids, and fluid resuscitation. The patient’s vital signs gradually recovered, and she was discharged after complete recovery two days later after complete recovery. This case suggests that recombinant humanized collagen, as a macromolecular protein, inherently carries the risk of triggering immediate-type anaphylactic shock despite its favorable safety profile. Clinicians should perform rigorous preoperative assessment, adhere to standardized procedures, and be proficient in the emergency management of anaphylactic shock to minimize the risk of severe adverse reactions and ensure medical safety.