Q. A 24-year-old female presents to your clinic with a complaint of sudden onset of swelling in her hands and face (see image). She reports that the swelling began approximately 2 hours prior to arrival and has been gradually increasing in severity. She also reports this was not the first time she had experienced such symptoms, and similar episodes had occurred several times in the past. The patient describes a history of similar episodes of swelling in various parts of her body, including her hands, feet, abdominal region, and face. She states that these episodes typically lasted for several days and were associated with severe itching, hives, and difficulty breathing. There is a strong family history of similar symptoms, with her mother and grandmother having a history of similar episodes of swelling. She believes that her mother was diagnosed with hereditary angioedema and is receiving treatment for the condition. Physical examination reveals swelling of her hands and face, with mild difficulty in swallowing and speaking. The patient's airway is patent, and she has no signs of respiratory distress. The remainder of her physical examination is unremarkable. You recognize the patient's history, family history, and physical examination are consistent with a possible diagnosis of hereditary angioedema. You order laboratory testing to confirm the diagnosis, which demonstrates elevated levels of C4. Based on her diagnosis, which of the following is the LEAST likely trigger of this patient's symptoms?