Anaphylaxis is a severe and potentially life-threatening allergic reaction that requires immediate medical attention. Also referred to as anaphylactic shock, it can develop rapidly and affects people of all ages.
Signs and Symptoms of Anaphylaxis
Anaphylaxis can manifest within minutes of exposure to an allergen. Common symptoms include:
- Skin Reactions: Itchy skin or a raised, red rash (hives)
- Swelling: Particularly around the eyes, lips, hands, feet, mouth, throat, or tongue, which may cause breathing and swallowing difficulties
- Breathing Issues: Wheezing and shortness of breath
- Digestive Symptoms: Abdominal pain, nausea, and vomiting
- Circulatory Symptoms: Feeling lightheaded or faint, collapse, and unconsciousness
What to Do in an Emergency
Anaphylaxis is a medical emergency. Prompt treatment is critical.
Administer Adrenaline: If available, give an injection of adrenaline (epinephrine) as soon as symptoms appear. Many people at risk of anaphylaxis carry auto-injectors.
- Inject into the outer thigh muscle.
- Hold the injector in place for 5 to 10 seconds.
- Call 999 for an ambulance, even if adrenaline is administered.
Repeat Dose if Necessary: If symptoms do not improve after 5 to 10 minutes, or if they worsen after initial improvement, give a second injection in the opposite thigh.
Positioning:
- Have the person lie flat with their legs raised to improve circulation.
- If breathing is difficult, allow them to sit up.
- If unconscious, place the person in the recovery position (on their side with one leg and arm supporting them, and head tilted back).
CPR if Needed: If breathing or heart function stops, perform cardiopulmonary resuscitation (CPR) until help arrives.
Further treatment will be provided in a hospital setting.
Common Causes and Triggers of Anaphylaxis
Anaphylaxis results from the immune system’s severe reaction to a normally harmless substance known as an allergen. Common triggers include:
- Insect Stings: Particularly bee and wasp stings
- Food Allergens: Peanuts, tree nuts, milk, seafood, etc.
- Medications: Such as certain antibiotics
Reactions usually occur within minutes but can sometimes be delayed by up to four hours.
Preventing Future Episodes of Anaphylaxis
If you have experienced anaphylaxis, it’s crucial to identify and avoid triggers. Steps to prevent further episodes include:
- Specialist Referral: You may be referred to an allergy clinic for testing, assessment, and advice on managing allergies.
- Adrenaline Auto-Injectors: Carry two auto-injectors at all times for emergency use.
Who is at Risk?
Anaphylaxis is uncommon but can affect people of all ages. Individuals with other allergic conditions, such as asthma or atopic eczema, have a higher risk of developing anaphylaxis. While anaphylaxis is life-threatening, deaths are rare with prompt treatment. In the UK, around 20 deaths occur each year from anaphylaxis, but most people make a full recovery with timely care.
Causes of Anaphylaxis: Triggers and Immune System Reactions
Anaphylaxis is a severe allergic reaction caused by an overreaction of the body’s immune system, which typically serves as a defense against illness and infection. In cases of anaphylaxis, the immune system mistakenly identifies a harmless substance as a threat and releases chemicals like histamine, triggering the reaction.
Common Triggers of Anaphylaxis
The substances that most often trigger anaphylaxis include insect stings, certain foods, medications, and other specific allergens. Below is a detailed overview of each category:
1. Insect Stings
The majority of insect-related anaphylactic reactions are caused by wasp and bee stings. However, any insect bite or sting can potentially lead to anaphylaxis.
- Prevalence: Around 1 in 100 people may experience an allergic reaction to a wasp or bee sting, but only a small fraction develop severe anaphylaxis.
2. Foods
Foods are a significant cause of anaphylaxis, particularly peanuts, which account for more than half of all food-related cases. Other common food triggers include:
- Nuts: Such as walnuts, cashews, almonds, brazil nuts, and hazelnuts
- Dairy: Milk
- Seafood: Fish and shellfish
- Eggs
- Certain Fruits: Including bananas, kiwi fruit, grapes, and strawberries
3. Medications
Certain medicines can cause anaphylaxis in a small percentage of people. These include:
- Antibiotics: Especially penicillin and penicillin-like antibiotics
- General Anesthetics: Used during surgeries for muscle relaxation
- Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Such as ibuprofen and aspirin
Note: The risk of developing anaphylaxis from these medications is low, often ranging from 1 in 1,480 for NSAIDs to 1 in 10,000 for general anesthetics.
4. Contrast Agents
Contrast agents are dyes used in some medical imaging tests (e.g., X-rays) to improve the visibility of body structures.
- Risk: Less than 1 in 10,000 people may develop anaphylaxis from these agents.
5. Rubber Latex
Natural rubber latex can trigger an allergic reaction in less than 1 in 100 people. Workers in healthcare, beauty, catering, and certain other industries are more prone to latex allergies. Additionally, individuals with hayfever, asthma, eczema, or medical conditions like spina bifida are at greater risk.
6. Idiopathic Anaphylaxis
In some cases, no identifiable trigger can be found despite extensive testing. This is referred to as idiopathic anaphylaxis.
Managing and Preventing Anaphylaxis
If you know your triggers, taking precautions to avoid exposure is essential. Carrying adrenaline auto-injectors and being prepared to use them in emergencies can be lifesaving.
For more detailed advice and assessment, individuals with a history of anaphylaxis are often referred to a specialist allergy clinic.
Treating Anaphylaxis: Immediate Actions and Emergency Care
Anaphylaxis is a medical emergency requiring swift action to prevent potentially life-threatening consequences. If you suspect someone is experiencing anaphylaxis, immediate treatment with adrenaline (epinephrine) and a call for emergency medical help are crucial.
Immediate Actions for Treating Anaphylaxis
- Use an Adrenaline Injector: If available, administer an adrenaline auto-injector immediately.
- Call 999 for emergency assistance as soon as possible, even if adrenaline is used.
- Remove Visible Triggers: If a wasp or bee sting is stuck in the skin, carefully remove it.
Administering Adrenaline
Adrenaline works by narrowing blood vessels (raising blood pressure), reducing swelling, and opening airways to ease breathing difficulties. The injection should be given as soon as symptoms of anaphylaxis are suspected, such as:
- Breathing problems
- Feeling faint or dizzy
- Loss of consciousness
How to Administer the Injection:
- The person with anaphylaxis can self-administer if able, but others may need to help if they are unable (e.g., a young child or unconscious individual).
- Follow Instructions: Read and understand the instructions on using an auto-injector when first prescribed.
- Injection Site: Inject into the outer thigh muscle and hold the syringe in place for 5-10 seconds. It can be administered through clothing.
- Call 999: Even if symptoms improve, immediate emergency assistance is essential.
- Second Dose: If symptoms do not improve or return after 5-10 minutes, administer a second dose in the opposite thigh.
Positioning and Resuscitation
- Lying Down: In most cases, the person should lie flat with their legs raised to improve blood flow to the head and heart.
- Pregnant Women: Lie on the left side to prevent pressure on a major vein leading to the heart.
- Breathing Difficulties: If conscious but having trouble breathing, sit the person up.
- Unconsciousness: Ensure airways are open and place the person in the recovery position (on their side, supported by one leg and arm, with the head tilted back and chin lifted).
- CPR: If the person stops breathing or their heart stops, perform cardiopulmonary resuscitation (CPR) until help arrives.
Hospital Admission and Care
Even after receiving adrenaline, the individual must go to the hospital for observation, typically for 6-12 hours, as symptoms can reoccur. In the hospital:
- Oxygen Therapy: An oxygen mask may be used to assist with breathing.
- Fluids: Intravenous fluids may be administered to increase blood pressure.
- Additional Medications: Antihistamines and corticosteroids can help relieve symptoms.
- Blood Tests: Tests may be conducted to confirm anaphylaxis.
Discharge and Follow-Up Care
Once symptoms are under control, you may be discharged from the hospital. In severe cases, a longer hospital stay may be required. Upon leaving:
- Take-Home Medications: You may need to take antihistamines and corticosteroids for 2-3 days to prevent symptoms from returning.
- Follow-Up Appointment: A follow-up will provide advice on avoiding future episodes and may involve testing for triggers.
- Emergency Auto-Injector: You will likely be given an adrenaline auto-injector for emergency use.
Learn More: Explore further information on preventing anaphylaxis and managing allergies.
Preventing Anaphylaxis: Steps to Reduce Risk and Manage Allergies
If you have experienced anaphylaxis, there are several steps and precautions you can take to reduce the risk of future episodes. Proper management and preparation are key to living safely with this severe allergic condition.
Allergy Clinic Referral and Testing
To identify what triggered your anaphylaxis, you may be referred to a specialist allergy clinic. Identifying triggers allows you to take steps to avoid future reactions. Tests used to diagnose allergies include:
- Skin Prick Test: A tiny amount of a suspected allergen is applied to your skin to see if it reacts (becomes red, raised, and itchy).
- Blood Test: A sample of your blood is analyzed for immune responses to specific allergens.
Learn more about diagnosing allergies and available tests.
Adrenaline Auto-Injectors
If you are at risk of experiencing another anaphylactic episode, you may be prescribed an adrenaline auto-injector for emergency use. There are three main types:
- EpiPen
- Jext
- Emerade
Using an Auto-Injector
Each type of auto-injector has slightly different instructions, so make sure you are familiar with how yours works. You can request a “trainer” kit for practice. Important points to keep in mind:
- Carry Your Auto-Injector at All Times: This can be lifesaving in an emergency. It’s also recommended to have an emergency card or bracelet with details of your allergy and your doctor’s contact information.
- Avoid Temperature Extremes: Heat can reduce the effectiveness of adrenaline. Do not store your auto-injector in the fridge or a hot car.
- Check Expiry Dates: Expired injectors offer limited protection. Manufacturers often provide reminder services for upcoming expiry dates.
- Children and Dosing: Children need to switch to an adult dose once they reach 30 kg (approximately 4.5 stone).
- Timely Use: Use adrenaline as soon as you suspect anaphylaxis, even if symptoms are mild. It’s better to administer early than to delay and risk severe symptoms.
Avoiding Triggers
If a trigger has been identified, take precautions to avoid exposure.
Food Allergies
Reduce the risk of exposure by:
- Checking Food Labels: Always read ingredient lists carefully.
- Informing Restaurant Staff: Clearly communicate your allergies to ensure safe preparation.
- Be Cautious of Cross-Contamination: Some foods, such as sauces, may contain hidden allergens.
Learn more about managing food allergies safely.
Insect Stings
To reduce your risk of being stung:
- Move Away Calmly: Do not swat at or wave your arms around wasps, bees, or hornets.
- Use Insect Repellent: Especially if spending time outdoors.
Specialist Treatment: Certain allergy centers offer desensitization treatment for those at high risk, such as beekeepers or gardeners.
Medicine Allergies
If you are allergic to certain medications, alternatives are usually available. For example:
- Penicillin Allergies: Macrolides may be an alternative.
- NSAIDs (Ibuprofen, Aspirin): Paracetamol may be a safer option; check ingredient labels carefully.
- General Anesthetics: Local anesthetics or epidurals may be used instead.
- ACE Inhibitors: Other blood pressure medications like calcium channel blockers may be prescribed.
Always Inform Healthcare Professionals: Ensure doctors, pharmacists, and medical staff know about your medication allergies.
Contrast Agents
In some cases, using contrast agents in medical imaging is necessary despite the risk. Pre-treatment with antihistamines and corticosteroids can help reduce or prevent anaphylactic reactions.
By taking these preventive measures, carrying essential medication, and being aware of your triggers, you can significantly lower your risk of experiencing another anaphylactic episode. Stay informed and prepared to ensure the best possible management of your condition.
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