What type of reaction does anaphylaxis typically cause?

Anaphylaxis is a severe and potentially life-threatening allergic reaction that typically results in respiratory distress due to upper airway swelling. During anaphylaxis, the immune system releases a large amount of histamine and other chemicals in response to an allergen, leading to rapid inflammation and swelling of the airways. This swelling can severely obstruct airflow, which manifests as difficulty in breathing, wheezing, and stridor.

The other options describe symptoms that are commonly associated with less severe allergic reactions or other illnesses. For example, while coughing and sneezing (a common response to allergens) may occur, they are not the defining features of anaphylaxis. Localized redness and swelling are indicative of localized allergic reactions, but anaphylaxis involves systemic reactions affecting multiple body systems, particularly the respiratory system. Fever and malaise typically point to an infectious process rather than an allergic reaction, which is why they are also less relevant in the context of anaphylaxis.

Understanding the severe impact of upper airway swelling during anaphylaxis is crucial for recognizing the need for immediate medical intervention, which often includes the administration of epinephrine to quickly reverse symptoms and prevent respiratory failure.