What are some signs of an allergic reaction?

The signs of an allergic reaction are characterized by the body's immune response to a substance it identifies as harmful, even when it may not be. The correct answer identifies common physical manifestations of this reaction. Rash, itching, swelling, and difficulty breathing are direct responses that occur when the body releases histamines and other chemicals in reaction to an allergen.

A rash or hives may develop on the skin, indicating inflammation, while itching is a common symptom as the body attempts to rid itself of the perceived threat. Swelling, particularly around the eyes, lips, or throat, can indicate a more severe reaction and may lead to anaphylaxis, which is a life-threatening condition that requires immediate medical attention. Difficulty breathing can occur if the airways narrow, highlighting the serious nature of such reactions.

The other symptoms listed in the other choices, while they may occur in various conditions, are not specific indicators of an allergic reaction. Loss of appetite and drowsiness can be associated with a variety of illnesses or conditions, anxiety and restlessness might indicate stress or panic rather than an allergic response, and headache and nausea can be symptoms of numerous other medical issues, but they do not directly point to an allergy. Thus, the symptoms listed in the correct choice distinctly