Causes of anaphylaxis

Causes of Anaphylaxis: What Triggers a Severe Allergic Reaction

Anaphylaxis happens when the immune system misreads a harmless substance as a mortal threat and floods the body with inflammatory chemicals all at once. Knowing your personal triggers is the single most protective thing you can do, per NHS guidance on anaphylaxis.

The Common Triggers

• Foods: peanuts and tree nuts, milk, eggs, fish, shellfish, wheat, soy, sesame - the most frequent triggers, especially in children
• Medicines: antibiotics (especially penicillins), painkillers like ibuprofen, anaesthetics, and contrast dyes used in scans
• Insect stings: bee and wasp stings in particular
• Latex: gloves, catheters, balloons - less common now but still significant
• Other triggers: exercise (sometimes combined with a food), cold exposure, and in some people no trigger is ever found (idiopathic anaphylaxis)

Why the Reaction Is So Violent

In a person who has become sensitised, the immune system keeps ready-made IgE antibodies against the trigger. On the next exposure, these antibodies order mast cells throughout the body to dump histamine and other chemicals simultaneously. Blood vessels leak and widen (blood pressure crashes), airways tighten (breathing fails), and skin and gut react. It is the speed and the whole-body spread that make anaphylaxis dangerous - not any single symptom.

Who Is at Higher Risk

• People with known allergies, asthma, eczema or hay fever
• Anyone who has had anaphylaxis before - the strongest predictor
• People whose previous reactions escalated quickly

The Classical Frame

Ayurvedic texts do not describe anaphylaxis itself - they predate the concept of allergy by two thousand years. What they do describe is Asatmya: an idiosyncratic intolerance where a substance harmless to most people harms a particular individual, and Satmya: the state of being suited to a substance. Dushivisha (cumulative low-grade toxicity) chapters describe recurring skin and systemic reactions in susceptible people. These are interpretive parallels, useful for thinking about individual susceptibility - they change nothing about the emergency.

Frequently Asked Questions

Can anaphylaxis happen on first exposure to a trigger? Rarely, but yes - sensitisation can occur through unknown prior contact. Most reactions, though, happen after at least one prior exposure.

Do triggers stay the same for life? Often, but not always. Children can outgrow milk and egg allergies; nut and shellfish allergies usually persist. New triggers can also appear in adulthood.

If I had a mild reaction once, can the next be severe? Yes. The same trigger can produce a worse reaction on a later exposure - a mild past reaction is not a safety certificate.

What is idiopathic anaphylaxis? Anaphylaxis where no trigger can be identified despite testing. It is managed the same way: epinephrine first, specialist care, and a written action plan.