What type of reaction is characterized by swelling, difficulty breathing, and sudden onset?

Anaphylactic shock is characterized by a rapid and severe systemic allergic reaction that can occur within minutes of exposure to an allergen. During this reaction, the body releases a large amount of histamine and other chemicals, which leads to symptoms such as swelling, difficulty breathing, hives, and potentially life-threatening drops in blood pressure. This sudden onset is a key indicator that distinguishes anaphylaxis from other types of allergic or respiratory responses.

In contrast, while asthma attacks can also involve difficulty breathing and swelling of the airways, they typically build up over a slightly longer period and are often triggered by specific allergens or irritants rather than occurring suddenly without warning. Panic attacks involve overwhelming feelings of fear and physiological symptoms but do not generally cause the type of physical swelling associated with anaphylaxis. Allergic rhinitis primarily affects the nasal passages and does not create the acute, systemic symptoms observed in anaphylaxis. Thus, the presence of all these symptoms alongside the rapid onset firmly identifies anaphylactic shock as the most appropriate answer.