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What is Hymenoptera Venom Allergy?
Hymenoptera venom allergy is an IgE-mediated allergic reaction to proteins contained in the venom of stinging insects — most commonly the common wasp (Vespula vulgaris), the honeybee (Apis mellifera), and, less frequently in the UK, hornets. When a sensitised individual is stung, the immune system releases histamine and other chemical mediators, which can produce reactions ranging from a large local swelling to life-threatening anaphylaxis.
According to the European Academy of Allergy and Clinical Immunology (EAACI), systemic allergic sting reactions occur in up to 7.5% of adults and up to 3.4% of children in Europe. Venom allergy is one of the leading identifiable causes of anaphylaxis in adults in the UK and across Europe.
Wasp Venom
Contains phospholipases, hyaluronidases, and antigen 5. Wasps can sting multiple times. Reactions tend to be more common in late summer when colonies are at their largest.
Bee Venom
Contains melittin, phospholipase A2, and apamin. Honeybees leave their barbed sting embedded in the skin and die after stinging once. Remove the sting promptly by scraping (not squeezing).
Risk Factors
Elevated baseline serum tryptase, mastocytosis, age over 40, cardiovascular disease, and concurrent ACE inhibitor or beta-blocker use are associated with more severe reactions.
Recognising Anaphylaxis After a Sting
Anaphylaxis is a severe, life-threatening, generalised allergic reaction. Symptoms typically develop within minutes of a sting. In accordance with RCUK 2021 guidance (reaffirmed 2025), suspect anaphylaxis if the following features occur suddenly after a sting:
▲ Airway
- Throat tightness or swelling
- Hoarse voice or stridor
- Difficulty swallowing
- Swelling of tongue or lips
△ Breathing
- Shortness of breath
- Wheezing or audible wheeze
- Persistent cough
- Chest tightness or pain
△ Circulation
- Feeling faint or dizzy
- Rapid or weak pulse
- Pale or grey skin
- Collapse or loss of consciousness
△ Skin / Other
- Widespread urticaria (hives)
- Flushing or itching
- Nausea, vomiting, cramping
- Sense of impending doom
Important: Anaphylaxis does not always involve a skin rash. Cardiovascular collapse or airway obstruction can occur without visible urticaria. Do not wait for all features to be present — act on any combination of airway, breathing, or circulatory symptoms occurring rapidly after a sting.
Emergency Action Steps — Step by Step
Remove the sting (bee stings only)
If stung by a honeybee, scrape the sting away sideways using a fingernail or card edge. Do not use tweezers or pinch the venom sac, as this injects more venom. Wasp stings do not remain embedded in the skin.
Alert someone nearby
Inform a relative, friend, colleague, or bystander that you have been stung and may be having an allergic reaction. Do not remain alone. Tell them where you keep your adrenaline auto-injector.
Sit or lie down — choose the best position
Lie flat with legs raised if you feel faint or dizzy (improves blood flow to the heart). Sit upright if you have breathing difficulty. Lie on your side (recovery position) if you are unconscious or vomiting. Do not stand up suddenly — positional changes can precipitate cardiac arrest in severe anaphylaxis.
Take an antihistamine (for mild reactions)
For mild localised or general urticarial reactions without airway, breathing, or circulatory symptoms, a non-sedating antihistamine — such as cetirizine 10 mg, loratadine 10 mg, or fexofenadine 120 mg — may be taken. Antihistamines are slow-acting and must never replace adrenaline if anaphylaxis features are present. Per updated RCUK 2021 guidance, antihistamines are not recommended as first-line treatment for anaphylaxis in a hospital setting.
USE YOUR ADRENALINE AUTO-INJECTOR immediately if any of these are present:
- Throat tightness, hoarseness, or difficulty swallowing
- Shortness of breath, wheezing, or persistent cough
- Chest tightness or chest pain
- Feeling faint, dizzy, weak, or about to collapse
- Rapid spread of urticaria with any of the above features
- Swelling of the face or tongue
Administer into the outer mid-thigh (can be given through clothing). Hold firmly for 10 seconds. Note the time.
Call 999 immediately after using adrenaline
State: “I am having a severe allergic reaction (anaphylaxis). I have used my adrenaline auto-injector. I need a paramedic ambulance.” Give your exact location. Even if symptoms improve rapidly, all patients who have used an adrenaline auto-injector must be assessed in hospital. Biphasic anaphylaxis — a second wave of symptoms — can occur 1–72 hours later in up to 20% of cases.
Second dose of adrenaline if no improvement after 5 minutes
If symptoms do not improve or worsen within 5 minutes of the first injection, administer the second adrenaline auto-injector into the opposite thigh. Current RCUK 2021 guidance and BSACI recommendations emphasise that a repeat dose of intramuscular adrenaline at 5 minutes is appropriate if the clinical picture does not resolve. Always carry two auto-injectors at all times, as recommended by the MHRA.
How to Use Your Adrenaline Auto-Injector
Technique varies between devices (e.g. EpiPen, Jext, Emerade). Always read the instructions for your specific device and practise with a trainer pen regularly. The general principle for all devices is:
Remove the device from its carrier tube. Take off the safety cap.
Grip the device firmly in your dominant hand. Do not put your thumb over the tip.
Place the needle end firmly against the outer mid-thigh (either bare skin or through clothing).
Push the device firmly against the thigh until you hear or feel a click. Hold firmly in place for 10 seconds.
Remove and massage the injection site gently. Hand the used device to the paramedic on arrival — do not re-cap the needle.
Dosing guidance (EAACI / BSACI):
- Children 7.5 kg – 25 kg: 0.15 mg adrenaline auto-injector (e.g. EpiPen Jr, Jext 150 micrograms)
- Children over 25–30 kg and adults: 0.3 mg adrenaline auto-injector (e.g. EpiPen, Jext 300 micrograms)
- Always carry two devices as a second dose may be required
- Check expiry dates regularly and replace before expiry — expired devices deliver reduced doses
Local Reactions vs Systemic Allergic Reactions
Not all reactions to stings indicate allergy. Understanding the difference helps you respond correctly:
| Reaction Type | Features | Action |
|---|---|---|
| Normal local reaction | Pain, redness, and swelling at the sting site only. Swelling <10 cm, resolves within 24–48 hours. Affects everyone who is stung. | Cold compress, antihistamine cream, oral antihistamine if itchy. No adrenaline needed. No specialist referral required unless repeated large local reactions. |
| Large local reaction (LLR) | Swelling >10 cm from sting site, may cross a joint, peaks at 24–48 hours, persists up to 7–10 days. Uncomfortable but not life-threatening. | Oral antihistamines and possibly a short course of oral corticosteroids. Consider allergy clinic referral if reactions are severe or recurrent. LLR alone is not an indication for venom immunotherapy per EAACI guidelines. |
| Systemic allergic reaction (Grades I–IV) | Symptoms beyond the sting site: urticaria, flushing, angioedema, nausea, bronchospasm, hypotension, or collapse. Severity graded I (mild skin only) to IV (cardiac/respiratory arrest). | Grades II–IV: use adrenaline auto-injector, call 999. All grades: urgent allergy clinic referral for venom allergy assessment and discussion of venom immunotherapy. |
Venom Immunotherapy (VIT): The Only Disease-Modifying Treatment
Venom immunotherapy (VIT) is the only proven disease-modifying treatment for Hymenoptera venom allergy, offering long-term protection against future systemic sting reactions. In eligible patients, it reduces the risk of anaphylaxis from a subsequent sting from over 60% to less than 5%.
VIT involves a structured course of subcutaneous injections of purified venom extract, building from a very small initial dose to a protective maintenance dose. The mechanism of action involves the induction of immune tolerance: production of blocking IgG and IgG4 antibodies, development of antigen-specific regulatory T cells producing IL-10, suppression of mast cell and basophil reactivity, and a shift from Th2 to Th1 immune responses.
Who is Eligible for VIT? (EAACI Guidelines)
Strongly Recommended
- Adults with grade III–IV systemic reactions (cardiovascular/respiratory involvement)
- Adults with grade II reactions AND elevated baseline serum tryptase or mastocytosis
- Individuals with significantly impaired quality of life due to sting fear
Also Considered
- Adults with grade II reactions (urticaria + other systemic features) after full risk assessment
- Children with grade III–IV reactions (grade I–II in children without cardiovascular features generally have a favourable natural history)
- Patients over 60 — evidence from 2025 supports VIT safety and efficacy in older adults
Not Recommended
- Large local reactions alone (no systemic features)
- Normal local reactions
How VIT Works at the London Allergy and Immunology Centre
Before starting VIT, our specialists conduct a comprehensive diagnostic workup including:
- Detailed clinical history — sting type, reaction grade, comorbidities, medications
- Skin prick and intradermal testing to wasp and bee venom
- Specific IgE blood tests including component-resolved diagnostics (e.g. ALEX, ISAC molecular testing) to differentiate true bee from wasp sensitisation and identify cross-reactive carbohydrate determinants (CCDs)
- Baseline serum tryptase measurement to assess for underlying mastocytosis
- Risk stratification using the validated Mueller grading scale
VIT is administered as a course of subcutaneous injections: an up-dosing phase (typically weekly injections over 3–4 months, or ultra-rush protocols over 1–2 days for selected patients) followed by maintenance injections every 4–8 weeks for at least 3–5 years. Published data suggest that protection persists in the majority of patients after completing a full course.
Omalizumab (anti-IgE) pre-treatment: For patients who experience systemic reactions during VIT (particularly those with mastocytosis or very high baseline tryptase), combination therapy with omalizumab (Xolair) prior to and during VIT is an established adjunct supported by published case series and emerging trial data as of 2025.
Sting Avoidance: Practical Advice for the UK
Avoidance alone cannot eliminate sting risk, but sensible precautions reduce exposure, particularly during the peak UK wasp season (August–October):
Outdoors
- Avoid walking barefoot on grass or near flowering plants
- Wear shoes, long sleeves and trousers when gardening
- Avoid brightly coloured or floral-patterned clothing
- Keep a lid on drinks when outdoors; check cans before drinking
Food and Fragrance
- Avoid eating sweet foods outdoors in late summer
- Keep food covered at picnics and barbecues
- Avoid heavily perfumed cosmetics, hair products, and sunscreens when outdoors
- Clear fallen fruit from gardens promptly
If an Insect Approaches
- Stay calm and move slowly away — do not swat
- Do not wave arms or run suddenly
- Avoid areas near known nests
- Contact a pest control service to remove nests near your home
Always Carry
- Two in-date adrenaline auto-injectors at all times
- Oral antihistamines for mild reactions
- A copy of your personal emergency action plan
- Medical ID bracelet (e.g. MedicAlert) indicating venom allergy
Arrange a Specialist Venom Allergy Assessment in London
If you or your child has experienced a systemic allergic reaction to a wasp or bee sting, prompt specialist assessment is essential. Our consultants at the London Allergy and Immunology Centre (Harley Street, City of London, and East London) offer:
Full Venom Allergy Workup
Skin prick tests, intradermal tests, specific IgE (RAST), ALEX and ISAC molecular testing, baseline tryptase
Venom Immunotherapy
Conventional, cluster, rush, and ultra-rush VIT protocols tailored to your clinical needs and schedule
Emergency Plans
Personalised written emergency action plans, adrenaline auto-injector training, and carer education
Insurance & GP Referrals
We accept most major private health insurance plans. GP referral letters welcome but not required for self-referral
Frequently Asked Questions
Important Notice
This page provides general educational information and is not a substitute for individual medical advice. Emergency action plans should be personalised by your allergy specialist. Always follow the specific written plan provided by your doctor. In an emergency, call 999 immediately.
References and Further Reading
- Sturm GJ, Varga EM, Roberts G, et al. EAACI Guidelines on Allergen Immunotherapy: Hymenoptera Venom Allergy. Allergy. 2018;73(4):744–764. doi:10.1111/all.13318. Reaffirmed in EAACI practical insights 2025.
- Resuscitation Council UK. Emergency Treatment of Anaphylaxis: Guidelines for Healthcare Providers. May 2021 (current edition). Available at: resus.org.uk
- British Society for Allergy and Clinical Immunology (BSACI). Guidelines on prescribing an adrenaline auto-injector. Updated guidance 2023–2024.
- National Institute for Health and Care Excellence (NICE). Anaphylaxis: Assessment and Referral after Emergency Treatment. CG134. 2011 (reviewed 2020). nice.org.uk/cg134
- Medicines and Healthcare products Regulatory Agency (MHRA). Drug Safety Update: Adrenaline auto-injectors — updated recommendations. August 2017.
- Golden DBK. Shared decision-making in insect sting allergy: to bee or not to bee? J Allergy Clin Immunol Pract. 2025;13:55–60.
- Sahiner UM, Durham SR. Hymenoptera Venom Allergy: How Does Venom Immunotherapy Prevent Anaphylaxis? Front Immunol. 2019;10:1959. doi:10.3389/fimmu.2019.01959
- Venom Immunotherapy in 2025: Practical Insights for Community Allergists. Current Treatment Options in Allergy. 2025 (Springer Nature).
- Anaphylaxis UK. Insect Sting Allergy — Patient Information. anaphylaxis.org.uk
- NHS. Anaphylaxis — Overview and Emergency Advice. nhs.uk/conditions/anaphylaxis
Medically reviewed: June 2026 | London Allergy and Immunology Centre | privateallergy.uk




