Acute Urticaria and Angioedema Associated with the Use of Levonorgestrel-Releasing Intrauterine System: A Case Report and Literature Review

L evonorgestrel-releasing intrauterine systems (LNG-IUS) not only provide effective and long-term contraception but are also used in the treatment of gynecological conditions such as abnormal uterine bleeding, adenomyosis, and prevention of endometrial hyperplasia [1,2] .While these devices are generally well-tolerated, their side effects include menstrual irregularities, ovarian cysts, and pelvic pain.Serious allergic reactions are rarely reported [3,4] .Progesterone hypersensitivity, or "autoimmune progesterone dermatitis, " is a rare hypersensitivity reaction developing against endogenous or exogenous progesterone, leading to cutaneous symptoms such as urticaria, angioedema, and dermatitis [5,6] .There are a limited number of cases in the literature reporting that levonorgestrel-containing intrauterine devices can cause allergic reactions due to progesterone hypersensitivity [7][8][9][10] .In this study, we aim to present a case of a patient who developed acute urticaria and angioedema two months after the insertion of LNG-IUS and did not respond to daily treatment with 15 mg of oral methylprednisolone and 5 mg of desloratadine, and to compare it with similar cases in the literature.Levonorgestrel-containing intrauterine systems (LNG-IUS) are widely used for contraception and the treatment of abnormal uterine bleeding.However, they can rarely lead to serious allergic reactions.This study aims to present a case of a 38-year-old woman who developed acute urticaria and angioedema two months after the insertion of an LNG-IUS and to synthesize similar cases reported in the literature.The patient's clinical findings, laboratory results, and treatment process were examined in detail.Allergic reactions associated with LNG-IUS and similar intrauterine devices were reviewed in the literature.Two months after LNG-IUS insertion for abnormal uterine bleeding, the patient developed widespread urticaria and facial angioedema.The urticarial lesions on the patient's back and torso are presented in Figures 1 and2.Despite daily treatment with 15 mg of oral methylprednisolone and 5 mg of desloratadine, her symptoms did not improve.The patient was evaluated by an allergist, and the removal of the LNG-IUS was recommended.Following the removal of the device, she responded to systemic therapy, and her symptoms completely disappeared within 15 days.Although acute urticaria and angioedema developing during LNG-IUS use are rare, clinicians should be aware of this potential adverse effect.In allergic reactions related to LNG-IUS, symptoms may resolve entirely with device removal and appropriate medical management.