Which type of reaction could result in fatal consequences if not treated promptly?

Anaphylaxis is a severe and life-threatening allergic reaction that occurs very quickly after exposure to an allergen. This reaction can lead to rapid onset symptoms, such as difficulty breathing, swelling of the throat, a drop in blood pressure, and loss of consciousness. The urgency in treating anaphylaxis stems from the fact that it can escalate to respiratory failure or cardiac arrest within minutes if not addressed immediately with appropriate interventions, such as the administration of epinephrine.

In contrast, while allergic reactions can be serious, they typically do not reach the same critical level of severity that anaphylaxis does. Autoimmune responses involve the immune system attacking the body’s own cells, which can be serious but usually do not present with the same acute life-threatening risk. Conditions like a psoriasis flare-up, while potentially uncomfortable and distressing, do not pose immediate life-threatening consequences. Therefore, anaphylaxis is the reaction that requires immediate medical attention to prevent fatal outcomes.