Certified Emergency Nurse (CEN) Practice Test

Flushing is a common initial symptom of an anaphylactic reaction. During anaphylaxis, the release of histamines and other chemicals from mast cells leads to vasodilation, which can cause redness and a sensation of warmth in the skin, particularly on the face and neck. This flushing may occur alongside other early symptoms such as itching or hives.

The other listed symptoms can indeed be associated with anaphylaxis but tend to manifest after the initial reaction has progressed or in response to severe drops in blood pressure and other systemic effects. Bradycardia is less typical in anaphylaxis, as tachycardia often occurs instead due to compensatory mechanisms. Hypotension is a later sign resulting from significant vasodilation and fluid shifts, while vomiting can occur as a gastrointestinal symptom during a reaction but is not usually among the earliest signs. Understanding this progression of symptoms is crucial for recognizing and treating anaphylaxis promptly.