Iatrogenic cold urticaria induced by tetrafluoroethane cryosurgery for gingival depigmentation: A rare case report.

Introduction: Gingival depigmentation procedure has gained widespread popularity in the recent years due to increased esthetic demands among patients. Among the various depigmentation procedures, cryosurgery is inexpensive and straightforward method. This case report discusses a rare complication associated with tetrafluoroethane (TFE) cryosurgical depigmentation method. Case Presentation: A 27‐year‐old systemically healthy male patient reported with the complaint of esthetic concerns associated with gingival melanin pigmentation. Cryosurgery with TFE was planned for the maxillary first quadrant. The patient developed angioedema immediately after exposure to the TFE cryogen during the procedure. Cold urticaria was considered, and the patient was prescribed nonsedating antihistamines for a week. One month follow‐up showed completely healed and depigmented gingiva without any recession or attachment loss. Conclusions: TFE cryosurgery depigmentation was found to be an effective depigmentation procedure. However, various complications including cold urticaria have been associated with its application. Therefore, the procedure's success depends on the proper case selection, complete isolation of the operating area, and preoperative test for gingival tissue response. Key points: Why is this case new information? Cold urticaria formation after applying cryosurgery has never been reported in the literature to the best of the authors' knowledge. What are the keys to the successful management of this case? Preoperative testing for tissue response to cryosurgery will prevent complications like cold urticaria. What are the primary limitations to success in this case? Improper medical history and not taking tissue response test for cryosurgery. [ABSTRACT FROM AUTHOR]