Are you a mosquito bite magnet? Here’s how to make your summer more pleasant

Don’t you just love balmy summer evenings? Gazing upon a dreamy sunset, chilled cocktail to hand, lazing in the garden or on a balcony somewhere exotic… But with all this loveliness comes one major problem – mosquito bites, aka everyone’s least favourite summer holiday accessory. And of course, mosquitos (and other flying horrors) don’t take an equal opportunities approach with their campaign of terror. Some people (like –sorry to be smug – me) escape unscathed, while others (like my poor husband) get blitzed into oblivion.

Why do mosquitos bite some people and not others?

I put this question, a perennial topic of debate during our family summer holidays, to Dr Raj Arora, NHS GP, aesthetic practitioner and founder of the Facebible clinic. It turns out you are more likely to get bitten if:

• You are pregnant.
• Mosquitos like your body odour or skin microbiome.
• You breathe out CO2 heavily.
• You sweat a lot.

Dr Raj explains: “Some studies have shown that blood type, our skin microbiome, body odour, body temperature, genetics and carbon dioxide emitted from our breath can all influence the amount we are bitten.”

And if you are pregnant, you may be more of a mosquito magnet. “This seems to be due to a combination of exhaling more carbon dioxide during pregnancy but also the natural increase in body temperature that pregnant women experience is thought to be attractive to mosquitos,” says Dr Raj.

“Mosquitos like the lactic acid and ammonia found in sweat. Mosquitos can smell sweat and therefore are more likely to attack those who sweat excessively. Although some studies have focused on particular blood types – usually blood type O – being more attractive to mosquitos the science is contradictory and more research is needed.”

Does vitamin B12 prevent mosquito bites? Or even Marmite?

There’s a good deal of online chat about this, but according to Dr Raj, there’s nothing concrete to back up that mosquitos are put off by the yeasty smell of vitamin B12, the B vitamin in which Marmite and Vegemite are rich. Sorry but B1 won’t help you either, as is anecdotally suggested. According to a research paper in 2005 on B vitamins as a home remedy against mosquitos and a more recent paper by Cambridge University Press in 2022 on thiamine (vitamin B1) as an insect repellent, there is no solid evidence here.

Best mosquito repellents

“Repellents with 50 per cent DEET (diethyltoluamide) are first-line recommendations to help prevent mosquito bites. This is safe for pregnant/breastfeeding women and also for children over the age of two months,” says Dr Raj. “If DEET is not tolerated, I recommend a repellent containing the highest strength formulation available of either icaridin (20 per cent), eucalyptus citriodora oil, hydrated, cyclised or 3-ethlyaminopropionate.”

Apply it thoroughly and reapply frequently, says Dr Raj, especially if you’re somewhere hot or if you’ve been swimming. “And apply repellent after sunscreen, which should contain 30 to 50 SPF as DEET can make sunscreen less effective.”

How to treat mosquito bites

Missed a bit with your repellent? It happens to the best of us. Dr Raj suggests the following steps to treat bites:

• Use a cold cream or ice pack to soothe.
• If the bites are on your legs, keep them raised to prevent excessive swelling.
• Use painkillers if they are stinging and sore.
• Take antihistamines to relieve itching.
• Apply a bite cream. These usually contain a weak steroid such as hydrocortisone to treat swelling or redness/inflammation. Some creams also include an antibacterial/antiseptic. Most local pharmacies and supermarkets will have their own brands.
• Try a pimple patch, the sort you use to clear spots. Anecdotally, they can help.

And don’t just leave them to fester, keep an eye on them. “If a bite looks infected – signs of increased redness, swelling, pain, pus/discharge or getting worse over time – then this must be seen to by a medical professional – reach out to your pharmacist or doctor,” says Dr Raj.

Finally, if you’ve been venturing a lot further afield than your patio, be aware that suspected malaria is a medical emergency. “If you have a high fever (38 degrees Celsius) and are feeling unwell after travelling in a malaria high-risk country then you must see your doctor immediately,”