Which of the following is a sign of anaphylaxis?

Anaphylaxis is a severe, potentially life-threatening allergic reaction that typically occurs rapidly after exposure to an allergen. Difficulty breathing and swelling of the throat or lips are hallmark signs of anaphylaxis. These symptoms arise due to the release of histamines and other chemicals in response to the allergen, leading to bronchoconstriction, swelling of the airway, and difficulty inhaling or exhaling properly. This presents an immediate danger to the individual and often requires urgent medical intervention, such as the administration of epinephrine.

The presence of swelling in the fingers, fever and headache, or nausea and sore throat can occur in various medical conditions but are not specific indicators of anaphylaxis. These symptoms may relate to other less critical allergic reactions, infections, or benign ailments rather than the acute severity associated with anaphylaxis.