Anaphylaxis

Anaphylaxis is the most severe form of allergic reaction. It occurs within minutes to an hour after exposure to the allergen (food, sting, medicine) and can affect several systems at once: skin (hives, swelling), breathing (swollen throat, difficulty breathing), circulation (drop in blood pressure, shock), digestion.

A fresh angle (the absolute emergency and adrenaline): anaphylaxis is a life-threatening emergency. Without rapid treatment, it can be fatal through asphyxiation or shock. The first-line treatment is adrenaline (auto-injector pen), to be given immediately into the thigh, even before the emergency services arrive (call them at the same time: 999 or 112 in the UK, 15 or 112 in France).

A crucial and little-known point: never hesitate or delay giving adrenaline if in doubt. The risk of not injecting far outweighs the risk of injecting unnecessarily. Antihistamines and corticosteroids are not enough in anaphylaxis (too slow); adrenaline is vital.

The food allergens most often involved: peanut, tree nuts (walnut, hazelnut, etc.), shellfish, fish, milk, egg, sesame, certain fruits. In Europe, 14 major allergens must be declared on labels and in catering.

The biphasic reaction: a little-known danger, after an improvement, a second wave of symptoms can occur several hours later (biphasic reaction). This is why every case of anaphylaxis requires hospital monitoring even after improvement.

Aggravating cofactors: some factors lower the threshold for a reaction: physical exertion (exercise-induced anaphylaxis, sometimes combined with a food), alcohol, infections, certain medicines. A food you normally tolerate can trigger a reaction if eaten before intense exercise.

Prevention: strict avoidance of the allergen, careful label reading, informing family and restaurants, always carrying the auto-injector (often two), an emergency action plan. Patient education is essential.