Les meilleures façons de prévenir et traiter les piqûres d'insectes

Some people always seem to be bitten while others are spared. This is because each of us has our own individual smell which can make us more attractive to insects. It is also possible that some people are bitten but their reactions are so mild they hardly notice the bite.

Dr Lizzie Kershaw-Yates, a GP at The Online Clinic, explains what happens to your body when an insect attacks:

"When an insect bites, it injects saliva into the skin. This triggers an immune response in which your white blood cells rush to the site. Histamine is released by this reaction and it causes swelling and irritation at the site. In some people this is exaggerated."

Rarely, a severe reaction can result in anaphylactic shock which requires immediate medical attention.

How to prevent insect bites

"In the UK, insect bites are a nuisance but overseas they can carry serious diseases like paludisme et dengue fever," explains Kershaw-Yates. "There are a range of measures, including covering up and using repellents, so choose what's best for your location."

Dr Andrew Thornber, GP and chief medical officer at Now Patient, suggests: "Avoid strong perfumes which may be in soap, shampoo, and deodorant, as well as perfume or aftershave."

Highly perfumed laundry products which leave a lingering fragrance can also be an issue.

If you are eating outside, keep food and drink covered as much as possible. Candles containing citronella may have a small effect on deterring insects. And electronic repellent devices used indoors will help ward off mosquitoes.

Clothing

Your clothing is important; insects will find it harder to bite if your arms and legs are covered. Bugs tend to be more prolific around sunrise or sunset, so pay particular attention at these times. And if you are very susceptible to bites, you may want to wear clothing that covers all your skin because determined insects will find that inch of exposed skin around your ankles.

Nets are important for sleeping in tropical locations where the risks of bites are more serious. You should also take anti-malaria tablets from your GP depending on where you are going on holiday.

Repellents

• Insect repellents work if they are applied regularly and need to be reapplied if you've been in the water.

• Products containing DEET are the most effective. Some people are concerned about safety, but an extensive review of the medical literature by the US Environmental Protection Agency concludes that: "The normal use of DEET does not present a health concern to the general population, including children."

• There is a wide variety of plant-based insect repellents on the market - lemon, eucalyptus, etc - and these are popular among customers who want a 'natural' alternative. However, none appears to match up well in terms of duration of action. In one review of a selection of mosquito repellents, a DEET-based insect repellent worked for 5 hours, but the effectiveness of all the plant-based products wore off within 30 minutes. In another, DEET worked for over 4½ hours longer than citronella-based repellents.

Pharmacist Thorrun Govind advises: "Always talk to your pharmacist first for advice if you are unsure of which repellents to buy. Some are not suitable for babies or younger children, for instance."

If, despite all these measures, you are bitten, what can you do?

Thornber advises simple measures to start with, such as:

• Washing with water and applying ice to reduce swelling.

• Taking paracetamol or ibuprofen to reduce any pain the bites cause.

• Avoiding scratching as this can cause an infection.

Again, talking to your pharmacist can help. Don't forget they have a private room for consultations if you need to show them the bites.

Govind says: "Your pharmacist will advise on antihistaminique creams, steroid creams and maybe antihistamine tablets. It's important to talk to your pharmacist because they may need to know if you are taking any other medications. They can also advise on whether oral antihistamines can be taken with alcohol, because of side effects like drowsiness."

If these simple measures don't appear to work, is it necessary to see your GP? Your pharmacist can be a good judge of this so ask them first to ensure you have tried all over-the-counter remedies.

Kershaw-Yates suggests these guidelines: "See your GP if the bites become very swollen and red, with the redness spreading to surrounding areas."

In rare cases, insect bites may also become infected (so try to avoid scratching them) and ooze pus. If you feel unwell, with des symptômes grippaux, such as a high temperature, swollen glands or dizziness, see your GP who may prescribe antibiotics. If you have been travelling overseas, your GP may want to identify what the bites are and if other treatment such as anti-malaria treatment is needed.

Severe allergic reactions are rare and tend to occur more with wasp and bee stings rather than bites. However, if you have multiple bites, a severe reaction becomes more likely.

Watch out for the following signs:

• You will feel unwell, find it hard to breathe or feel wheezy, feel faint, have a rapid heartbeat and possibly collapse.

• You or anyone seeing this should call for an ambulance immediately - dial 999 if in the UK.

Anaphylactic shock is life-threatening because your heart can stop. If you have a history of severe allergic reactions, you will probably be advised to carry an Epipen as a first-step treatment until medical help arrives.

To keep your holiday relaxed and as bite-free as possible, see your pharmacist first, pack the necessary medications and clothing, see your GP if you are travelling to an area where malaria is a risk, and remember to apply those repellents, especially at dawn and dusk.