[Anaphylactic shock]

Abstract

Anaphylactic shock is a severe, potentially life-threatening systemic allergic reaction. It can involve multiple organ systems and is triggered by medication, food, or insect stings. Epidemiological data vary due to differing definitions, but studies estimate that 0,26% of hospital admissions are due to anaphylaxis, with 1-3 deaths per million annually. The incidence of allergic reactions has increased, though anaphylaxis-related mortality remains stable. Triggers vary by age, with food allergies being common in children, and insect stings and medication predominant in adults.An initial allergen exposure sensitizes the immune system, resulting in IgE production and binding to mast cells and basophils. Upon re-exposure, allergen-IgE binding triggers the release of mediators like histamine, prostaglandins, and cytokines, causing vasodilation, bronchospasm, and capillary leakage. Risk factors include asthma, cardiac or thyroid conditions, and elevated IgE levels. Symptoms usually affect 4 organ systems: skin, gastrointestinal tract, respiratory tract, and cardiovascular system. Grading is based on the severeness of symptoms, ranging from mild skin reactions (grade 1) to respiratory or circulatory arrest (grade 4). A reliable diagnostic marker is elevated serum tryptase.The cornerstone of treatment is adrenaline, administered intramuscularly for rapid action. Fluid resuscitation with balanced electrolyte solutions and high-flow oxygen are also fundamental. Antihistamines and corticosteroids are used a bit later to prevent recurrence but have delayed onset. Adrenaline can also be nebulized or given intravenously in severe cases.Post-crisis management includes patient education, allergy identification, and an emergency kit with an adrenaline auto-injector.