What Is a Peanut Allergy Reaction?
A peanut allergy occurs when the immune system mistakenly identifies peanut proteins as harmful. This triggers a protective response, releasing chemicals like histamine that cause allergy symptoms. Peanut allergy differs from other food allergies (like tree nuts or shellfish) and is not the same as a food intolerance, which does not involve the immune system.
How Peanut Allergies Work
When someone with a peanut allergy eats even a small amount of peanut, their immune system produces immunoglobulin E (IgE) antibodies. These antibodies bind to mast cells, triggering the release of histamine and other chemicals, which lead to allergy symptoms.
Prevalence in Australia
Peanut allergy affects approximately 3% of Australian children, with cases also reported in adults. According to ASCIA, peanut allergy has become more common over the past few decades, reflecting trends seen globally.
Common Triggers and Hidden Sources
Common peanut allergy triggers in Australia include:
- Peanut butter
- Peanut oil (especially unrefined)
- Baked goods (cakes, biscuits)
- Asian sauces (satay, hoisin)
- Confectionery and desserts
Hidden sources may include cross-contaminated foods, workplace snacks, or catered meals. Even trace amounts can cause a reaction.
Symptoms of a Peanut Allergy Reaction
Mild to Moderate Symptoms
Symptoms often develop within minutes and may include:
- Itchy mouth, tongue, or throat
- Hives or skin redness
- Runny nose or sneezing
- Nausea, vomiting, or mild stomach pain
Severe Symptoms (Anaphylaxis)
Anaphylaxis is life-threatening and requires immediate emergency treatment. Signs include:
- Difficulty breathing or wheezing
- Swelling of the tongue or throat
- Dizziness or fainting
- Rapid drop in blood pressure
- Loss of consciousness
Delayed Reactions
Rarely, symptoms may appear hours after exposure. This can complicate diagnosis but should still be treated seriously.
How Fast Do Reactions Occur?
Most reactions begin within 5–30 minutes of exposure. Some can occur even faster. Immediate action is crucial.
Immediate Actions During a Reaction
Using an EpiPen
If anaphylaxis is suspected:
- Remove the EpiPen from its case.
- Hold firmly, blue to the sky, orange to the thigh.
- Remove the blue safety cap.
- Push the orange tip firmly into the outer mid-thigh (through clothing if necessary).
- Hold for 3 seconds.
- Call 000.
When to Call Emergency Services
Dial 000 immediately if:
- The person has breathing difficulty.
- Symptoms of anaphylaxis are present.
- There is uncertainty about the severity of symptoms.
Tell the dispatcher you suspect anaphylaxis and have used an EpiPen.
Monitoring After an Episode
Medical observation is essential after adrenaline use. Symptoms may return (biphasic reaction) within hours. Hospital monitoring is recommended for at least 4 hours post-episode.
Diagnosis and Medical Evaluation
Allergy Testing Methods
Common diagnostic methods include:
- Skin prick test
- Blood test (RAST or ImmunoCAP)
- Oral food challenge (under medical supervision)
Australian Guidelines for Diagnosis
ASCIA guidelines recommend referral to an allergist via a GP. Testing should only occur in safe, controlled environments.
What to Do After a First Reaction
- Book an appointment with your GP.
- Request a referral to an allergist.
- Keep a food and symptom diary.
- Avoid peanuts until evaluated.
Long-Term Management of Peanut Allergies
Avoidance Strategies
- Always read labels for food safety. FSANZ requires clear allergen labelling in Australia.
- Ask about ingredients when dining out.
- Be cautious of cross-contamination in shared environments, including food handling.
Emergency Action Plans
Australians with peanut allergies should have an ASCIA Action Plan for Anaphylaxis, which outlines what to do during a reaction.
Workplace Considerations
- Inform your employer about your allergy.
- Request peanut-free areas if possible.
- Ensure colleagues know how to respond in emergencies.
Informing Friends and Colleagues
Clear communication helps build a safer environment. Consider sharing your action plan with trusted people.
Treatment Options and Emerging Therapies
Antihistamines and Adrenaline
- Antihistamines: Help relieve mild symptoms like hives.
- Adrenaline (EpiPen): The first-line treatment for anaphylaxis. Life-saving when used promptly.
Oral Immunotherapy (OIT)
OIT aims to desensitise individuals to peanuts through gradual exposure. It is not yet standard care in Australia but is being explored.
Australian Clinical Trials and Research
Studies at institutions like the Murdoch Children’s Research Institute are testing new treatments, including OIT and vaccines.
Preventing Reactions and Raising Awareness
Labelling Laws and Food Standards
FSANZ mandates allergen declarations on packaged foods. However, precautionary labels (e.g. “may contain peanuts”) are voluntary.
School and Workplace Allergy Policies
Schools and many workplaces have allergy management policies. These often include nut-free zones and staff training.
National Peanut Allergy Awareness Efforts
Organisations like ASCIA lead campaigns to educate the public about food allergy risks and safety.
FAQ
What are the first signs of a peanut allergy reaction?
Itchy mouth or skin, hives, and nausea are common early signs.
How long after eating peanuts do allergy symptoms appear?
Usually within 5–30 minutes.
What should I do if someone has a severe allergic reaction?
Administer adrenaline immediately and call 000.
Can adults develop peanut allergies suddenly?
Yes, though it’s more common in childhood, adult-onset peanut allergy can occur.
What foods should be avoided with a peanut allergy?
Any food containing peanuts or processed in facilities that handle peanuts.
What is the difference between a peanut allergy and intolerance?
Peanut allergy involves the immune system; intolerance does not.
How can workplaces protect employees with peanut allergies?
Implement allergy declarations, educate staff, and minimise risks in shared spaces.
Is there a cure for peanut allergies?
There is no cure yet, but therapies like OIT show promise.
Are peanut allergies becoming more common in Australia?
Yes, rates have increased over recent decades.
What is the role of EpiPens in allergy management?
They provide life-saving adrenaline during anaphylaxis.
Key Points
- Peanut allergies can trigger severe, life-threatening reactions.
- Symptoms range from mild itchiness to anaphylaxis.
- Fast response with adrenaline (EpiPen) can save lives.
- Workplace safety and clear allergy plans are crucial.
- Australians can access tests, plans, and new therapies.
