Which of the following symptoms indicates anaphylaxis?

The symptoms of difficulty breathing, swelling, and hives are classic indicators of anaphylaxis, which is a severe allergic reaction that can be life-threatening. In this context, difficulty breathing could arise from airway constriction or swelling in the throat, making it hard for air to enter the lungs. The swelling, also known as angioedema, often occurs in the face, throat, and tongue. Hives, characterized by red, itchy welts on the skin, are another common manifestation of this acute reaction.

Anaphylaxis typically demands immediate medical attention due to the rapid onset of symptoms, which can escalate quickly, potentially leading to shock or death if not treated promptly with interventions like epinephrine. The combination of these three symptoms points to a systemic response to an allergen, underlining the seriousness of anaphylactic reactions.

In contrast, other symptoms listed do not characterize anaphylaxis. For instance, a combination of fever and chills can indicate an infection rather than an allergic response. Coughing and sneezing are more aligned with respiratory allergies or infections, and chest pain and nausea can result from a variety of conditions, including anxiety or gastrointestinal issues, rather than a direct indication of anaphylaxis.