Call 15 immediately if you notice:
- difficulty breathing, a changed voice or a swollen tongue or throat
- widespread hives, feeling faint, chest pain
- a sting in the mouth, the throat or near the eye
- multiple stings
- symptoms getting rapidly worse
15 (SAMU, French emergency medical service) · 112 (European emergency number) · 114 (for deaf or hard-of-hearing people)
If you know you are allergic and carry an adrenaline auto-injector, use it, then call 15.
Otherwise, a single Asian hornet sting causes sharp pain, redness and local swelling that subside within a few hours to a few days. It does not require an emergency consultation.
What to do straight away
- Move away. The hornet does not lose its sting and can sting several times. Leave the area calmly, without sudden movements — agitation attracts the other workers.
- Take off rings, bracelets and watch if you were stung on the hand or arm: the swelling may make them impossible to remove later.
- Clean the area with soap and water.
- Apply cold — an ice pack wrapped in a cloth, never ice directly on the skin — to limit pain and swelling.
- Keep watch for at least an hour. This is the time within which a severe allergic reaction most often appears.
Unlike the bee, the hornet does not leave its sting in the skin: there is nothing to remove.
When should you worry?
Three situations call for urgent medical advice, whatever your medical history.
An allergic reaction. This is the main danger: 89% of the serious envenomations recorded by Anses involved an allergic reaction, and in more than half of the serious cases linked to hornets, a single sting had been enough. It can happen to someone who has been stung before without any problem. Signs usually appear within minutes: hives away from the sting, a swollen face, difficulty breathing, feeling faint.
Multiple stings. The toxic reaction is proportional to the dose of venom received. A high number of stings justifies medical advice even without an allergy.
A sting in a sensitive area. Mouth, throat, tongue: the swelling can block the airways. Eye and eyelid: eye damage calls for specialist advice.
For any other unusual symptom, a French poison control centre answers 24/7 on 01 45 42 59 59.
What not to do
- Do not scratch. The risk of infection is real.
- Do not apply heat. The common belief that heat "destroys" the venom has no basis for hymenoptera stings, and a burn makes the wound worse.
- Do not use home remedies — vinegar, urine, soil, onion — on a sting that is getting worse.
- Do not take corticosteroids or antihistamines on your own initiative if you have signs of a general reaction: call 15, who will tell you what to do.
- Do not go back towards the nest to assess the damage or fetch a tool.
How long does a hornet sting last?
The sharp pain lasts from a few minutes to an hour. Local redness and swelling usually persist for 24 to 48 hours, sometimes longer if the sting is on a hand or foot.
Extensive swelling around the sting — several centimetres, getting worse over 24 to 48 hours — is a large local reaction. It looks alarming but is usually harmless. See a doctor if it spreads beyond a joint, if it comes with fever, or if signs of infection appear after a few days.
Should you see an allergist after a sting?
If you had a general reaction — hives away from the sting, feeling faint, difficulty breathing — the answer is yes. An allergy work-up can confirm the allergy and assess whether desensitisation, an effective treatment, is worthwhile.
A purely local reaction, even a large one, does not on its own justify a work-up.
How to avoid the next sting?
The most effective prevention fits in one sentence: check there is no nest before trimming, mowing or pruning.
Other useful habits:
- Stay more than 5 metres away from any nest you have spotted
- Do not make sudden movements if a hornet comes close: it will fly off on its own
- Cover sweet drinks outdoors at the end of summer
- Do not set up a home-made trap such as a bottle: Anses points out that these traps kill other insects essential to biodiversity and have almost no effect on the targeted nest
Is the Asian hornet dangerous to humans?
Sources
Information checked on 14/08/2026. This content is for information only and does not replace medical advice. If in doubt, call 15 (or 112) or see a doctor.