Allergic reactions range from mild skin symptoms to severe, life-threatening anaphylaxis. Anaphylaxis is a rapid, systemic hypersensitivity reaction that can cause airway swelling, breathing difficulty, circulatory collapse, and shock within minutes. Because progression can be sudden and unpredictable, allergic emergencies require immediate recognition and intervention.

Allergic reactions occur when the immune system overreacts to substances such as foods, medications, insect stings, latex, or environmental allergens. Mild reactions may involve hives, itching, localized swelling, nasal congestion, or mild wheezing. Anaphylaxis, however, involves multiple organ systems and may present with throat tightness, hoarseness, difficulty breathing, widespread hives, facial or tongue swelling, vomiting, dizziness, or loss of consciousness.

Emergency evaluation begins immediately with airway, breathing, and circulation assessment. Airway compromise due to swelling of the throat or tongue is the most dangerous feature and requires urgent attention. Oxygen is administered promptly, and continuous monitoring of vital signs is initiated. Low blood pressure or rapid heart rate may indicate circulatory involvement.

Early administration of intramuscular emergency medication is critical in suspected anaphylaxis. Delayed treatment increases risk of respiratory failure or cardiac arrest. Intravenous access is established for fluid support and additional medications as needed. Patients are positioned appropriately to maintain circulation and prevent collapse.

Observation is essential because biphasic reactions—recurrence of symptoms after initial improvement—can occur. Patients with severe reactions are monitored for several hours to ensure stability. In refractory cases, advanced airway support or intensive care may be required.

Risk assessment includes identifying the likely trigger and reviewing history of prior allergic reactions. Patients with known severe allergies may carry emergency auto-injectors, but emergency department management remains essential even after pre-hospital treatment.

Education at discharge includes allergen avoidance, prescription of emergency medications, and referral for specialist evaluation when necessary. Structured emergency protocols emphasize rapid recognition, immediate intervention, and vigilant monitoring to prevent fatal outcomes.