A nurse is monitoring a 6-month-old infant 20 minutes after administering a hepatitis B immunization. Which of the following findings is the nurse's priority?

Choice C rationale Hives on the child's neck is the priority finding because it can indicate an allergic reaction, which may progress to anaphylaxis. Anaphylaxis is a severe, life-threatening allergic reaction that requires immediate intervention. Hives are often the first sign of an allergic reaction and can quickly escalate to airway obstruction, difficulty breathing, and cardiovascular collapse. Early identification and treatment of an allergic reaction can prevent these severe complications. The nurse should be prepared to administer emergency medications, such as epinephrine, and provide respiratory support if needed. Choice A rationale Redness at the injection site is a common and expected local reaction following immunization. It typically resolves on its own without intervention. While it may cause some discomfort, it does not pose an immediate threat to the child's health and is not a priority over signs of a potential allergic reaction. Choice B rationale A temperature of 37.7°C (99.9°F) is a mild fever and a common response to immunizations as the body mounts an immune response. It is not usually cause for concern and can be managed with antipyretics if necessary. This mild fever does not indicate an urgent condition compared to the signs of an allergic reaction. Choice D rationale Prolonged crying can be a sign of discomfort or pain following an immunization but is not necessarily indicative of a severe reaction. It is important to assess the child's overall condition and provide comfort measures. However, it does not take precedence over signs of an allergic reaction, which require immediate attention.