Which of the following is NOT a common symptom of anaphylaxis?

In the context of anaphylaxis, the common symptoms typically involve severe and immediate reactions affecting the respiratory and cardiovascular systems, as well as the skin. Symptoms like swelling of the throat, rash or hives, and difficulty breathing are all hallmark signs related to this life-threatening allergic reaction.

Swelling of the throat occurs due to angioedema, which can obstruct the airway and lead to respiratory distress. The presence of rash or hives indicates an intense allergic response affecting the skin, and difficulty breathing arises from bronchoconstriction and edema in the airways.

A severe headache, while it can be experienced in various conditions, is not a typical symptom of anaphylaxis. Instead, the key indicators revolve around allergic reactions and physiological changes that threaten breathing and circulation. Thus, identifying severe headache as not being a common symptom of anaphylaxis is accurate.