A nurse is providing care to a client who is experiencing wheezing after receiving an antibiotic 20 min ago. Which of the following findings is the priority for the nurse to monitor for?

A. Lightheadedness: This can occur during anaphylaxis due to decreased cerebral perfusion, but it is less critical to monitor than the systemic blood pressure that causes it. B. Stomach pain: GI upset can occur during allergic reactions, but it is not life-threatening. C. Decreased blood pressure: After airway compromise (wheezing), the next stage of anaphylaxis is vascular collapse (distributive shock). Hypotension is a late and critical sign of anaphylactic shock. D. Urticaria: Hives are a common sign of an allergic reaction but are a skin manifestation and do not pose a threat to the patient's life.