Anaphylaxis Management

Anaphylaxis management is an emergency treatment that stops a severe, life-threatening allergic reaction and restores normal body function as quickly as possible.

During anaphylaxis (a sudden, extreme allergic reaction), the immune system releases a flood of chemicals that can cause blood pressure to drop and the airways to narrow or swell shut. The body can go into anaphylactic shock (a state where vital organs are not getting enough blood) within minutes. Treatment works by reversing these changes: opening the airways, raising blood pressure back to a safe level, and calming the immune system's overreaction.

This treatment is used whenever a patient shows signs of anaphylaxis — a severe allergic reaction that affects the whole body. It is always urgent and does not wait for test results. The trigger can sometimes be identified, but treatment begins immediately regardless.

• Severe reaction to an insect sting (such as a bee or wasp)
• Severe reaction to a food allergen (such as peanuts, shellfish, tree nuts, or milk)
• Severe reaction to a medication (such as antibiotics or pain relievers)
• Severe reaction to a contrast dye (the liquid used during CT or MRI scans)
• Exercise-induced anaphylaxis (a rare reaction triggered by physical activity, sometimes combined with a specific food)
• Anaphylaxis with no identifiable trigger, called idiopathic anaphylaxis

Anaphylaxis management is the right response any time a patient has two or more body systems affected at the same time — for example, hives (raised, itchy skin welts) together with breathing difficulty or a sudden drop in blood pressure. There is no situation in which a confirmed anaphylactic reaction is left untreated.

Certain approaches used within this management may need to be adjusted — not avoided entirely — in specific patients, for example:

• Patients taking beta-blockers (a type of heart medication) may respond less strongly to the first-line medicine, requiring additional treatments
• Pregnant patients require positioning adjustments to protect blood flow to the baby
• Patients with certain heart conditions may need closer monitoring during treatment

The risks of the treatment itself are generally small compared to the danger of leaving anaphylaxis untreated, but they are worth understanding.

• A biphasic reaction (a second wave of anaphylaxis symptoms returning hours after the first wave has been treated) — this is why observation in hospital is standard
• Rapid heart rate or a feeling of strong heartbeat from the medicine used to reverse the reaction
• Anxiety, trembling, or headache as common short-term side effects of the same medicine
• High blood pressure, temporarily, especially if the medicine is given in a large amount
• Fluid overload (too much intravenous fluid given too quickly), which can stress the heart and lungs
• Complications from a breathing tube if one was needed to keep the airway open
• Tissue damage at the injection site if certain medicines leak outside the vein

Anaphylaxis management is an emergency, so there is no planned preparation the patient can do beforehand in the usual sense. However, patients with a known history of severe allergic reactions are usually given guidance by their allergy doctor in advance, which can make emergency treatment faster and safer.

Before an emergency occurs, patients with a history of anaphylaxis are typically advised by their doctor to:

• Carry a self-injection device (an auto-injector) containing the medicine used to stop the reaction, and keep it within reach at all times
• Wear or carry a medical alert card or bracelet that states their known allergens
• Inform all healthcare providers — including dentists and pharmacists — about their allergy history
• Avoid known triggers as much as possible, and have a written emergency action plan from their doctor

When a patient arrives at an emergency setting, the medical team does not wait for extensive tests before starting treatment. However, they will usually carry out quick checks at the same time as treatment begins:

• Checking blood pressure and pulse continuously
• Measuring blood oxygen levels using a small clip on the finger (a pulse oximeter)
• Asking about recent exposures to food, medicine, insects, or other possible triggers
• Taking a brief history of any known allergies and current medications

Once the patient is stabilised, blood tests may be taken to measure tryptase (a substance released by immune cells during anaphylaxis), which can help confirm the diagnosis. This is done after treatment, not before.

The treatment itself generally follows these steps, though the exact order may vary depending on the patient's condition:

• 1. The patient is placed in a position that supports breathing and blood flow — usually lying flat with legs raised, unless breathing is easier sitting up
• 2. The first medicine is injected, usually into the outer thigh muscle, to quickly reverse the dangerous effects on the airways and blood pressure
• 3. Oxygen is given through a mask if blood oxygen levels are low
• 4. An intravenous (IV) line is inserted into a vein so fluids and additional medicines can be given directly into the bloodstream
• 5. If blood pressure remains low, IV fluids are given rapidly to support circulation
• 6. Additional medicines — such as antihistamines (medicines that calm allergic reactions) or corticosteroids (medicines that reduce swelling and dampen the immune response) — may be given to prevent symptoms from returning
• 7. If the airway is severely swollen and the patient cannot breathe adequately, the medical team may insert a breathing tube or perform another procedure to secure the airway
• 8. The patient is monitored continuously until stable

Even after the immediate reaction is controlled, patients are kept under close observation because anaphylaxis can return. The length of monitoring depends on how severe the initial reaction was, how quickly the patient responded to treatment, and whether the patient has other health conditions — your medical team will decide the right duration.

• Hospital observation is standard after anaphylaxis, usually for several hours at minimum, and sometimes overnight or longer if the reaction was severe or the response to treatment was slow
• Vital signs (heart rate, blood pressure, breathing rate, and oxygen levels) are checked regularly throughout the observation period
• Patients are usually advised not to drive or operate machinery for at least the remainder of the day after treatment
• A prescription for a self-injection auto-injector is typically arranged before the patient leaves, if they do not already have one
• Follow-up with an allergy and immunology specialist is strongly recommended to identify the specific trigger, carry out allergy testing, and discuss long-term strategies such as allergen immunotherapy (a treatment that gradually makes the immune system less sensitive to a trigger)
• Patients are advised to continue avoiding the suspected trigger and to keep their auto-injector with them at all times going forward
• Family members or close contacts are often shown how to use the auto-injector in case of a future emergency
• Any new symptoms — especially difficulty breathing, swelling, or hives — after returning home should prompt an immediate return to hospital