Busting myths about preventing and treating mosquito bites

Mozzie bites are an unavoidable part of the Australian summer.

But how much do you actually know about avoiding itchy bites — and which "cures" are just old wives' tales?

We asked mozzie bite expert Dr Cameron Webb, who's a medical entomologist at the University of Sydney and NSW Health Pathology, to bust the myths around preventing and treating mosquito bites. Here's what he said.

How do I stop mosquito bites itching?

There isn't really one single solution.

If you put a cold pack on your bite, that'll reduce some of the inflammation. You can also try the anti-itch cream you buy at the chemist or supermarket.

Keeping that itchy bite clean is really important as well, because you don't want to get a secondary infection.

And there's lots of urban myths about hot and cold water and applying any number of substances that you can imagine — from mayonnaise to antibacterial mouthwash.

I think anything that relieves that itch and works for you is probably fine. I would even just suggest some non-fragranced moisturiser.

Do so-called mosquito click devices work?

There are some clicker-type devices that you'll see marketed to alleviate the itch [by zapping yourself].

I have not seen a scientific study that really demonstrates conclusively that [they're effective].

If it works for you, there's no evidence it's doing any harm. But it's not something I generally reach for.

How long do mozzie bites last?

This will vary from person to person.

Before a mosquito starts sucking your blood, she spits into you — it's the female mosquito that needs blood to help develop her eggs.

In the same way that we all differ in our reaction to food allergens, we all differ in our reaction to mozzie spit. So some people will react really badly, while others will hardly react at all.

But it does seem like the more you scratch, the longer the irritation lasts — although I don't think there's actual science to back that.

Why do my mosquito bites get so big?

It probably has a lot to do with your previous exposure to mosquito bites.

It's quite common that young children will have a worse reaction, as will people who have just come to Australia for the first time.

We develop a certain level of tolerance or immunity to our local mosquitoes when we've grown up being bitten.

This is because there's a different chemical cocktail in the spit of different mosquitoes around Australia, and even throughout our cities.

For example, in Sydney we've got about 60 different types of mosquitoes, so you might be getting bitten by a different type of mosquito even if you're just moving 10 kilometres across town.

I get bitten more than my friends. Do I have sweet blood?

When mosquitoes get close to you, [they can detect] your body temperature, but particularly the smell of your skin.

There's lots of different chemical compounds on your skin. Some of them attract mosquitoes, and some of them even repel mosquitoes — so you've probably got stinkier skin.

Can mosquitoes bite my face?

When you're outdoors, you should definitely be putting mosquito repellent on your face.

There's not much point overnight though, as it'll generally rub off and won't last the duration of the evening.

You're better off ensuring you've got fly screens on your windows where possible or plugging in smokeless mosquito repellents and insecticides. But you should never burn a mosquito coil or stick indoors, because you don't want to be breathing in that smoke.

Do mosquito zappers work?

They'll kill other flying insects — like flies and beetles and moths — but, generally speaking, mosquitoes aren't very attracted to them.

Every mozzie they kill is one less to bite you, but it's probably the least effective way to control mozzies.

Do natural mosquito coils, patches and wristbands work?

Devices that release citronella and other plant-based materials will offer a little assistance, but certainly not enough to provide complete protection.

And mosquito wristbands and patches have been shown not to really work at all. Apart from a centimetre either side of the band or patch, you're not really going to get any protection.

Does natural citronella spray work?

Not really.

The two ways to stop mosquitoes biting you is either to use a chemical to switch off the blood feeding urges of a mosquito, or to disguise your skin's smell.

So some of those plant products will camouflage you a little bit against the mosquitoes, but they're still buzzing around trying to find you.

Whereas those other chemical products will pretty much knock out the mosquito or stop that blood-feeding gene, which is more effective.

Is DEET bad for me?

No.

Insect repellents in Australia have been tested by the Australian Pesticides and Veterinary Medicines Authority, who make sure they're safe and effective to use.

DEET has been available for more than 70 years now, and it's used by billions of people around the world.

But if you're concerned, you could think about the strength of the repellent, which often determines how long it lasts, not how many mosquitoes it keeps away.

So if you're only outside for a short period of time, you don't necessarily have to reach for the strongest tropical-strength repellent.

You can choose a lower dose, kid-friendly type repellent, because over a shorter period of time it's probably still going to provide you the same level of protection. And you might find that that's a product you're more happy to use on a regular basis.

How has La Niña affected the mosquito season this year?

Mosquitoes need both water and warmth to complete their life cycle.

There's been lots of water across much of eastern Australia, but in some cases there's probably been too much water, so that washes away the eggs and the wrigglers that are found in the water.

But as soon as those floodwaters recede into stagnant pools and puddles, that's going to coincide with the warmer weather that we're going to get now that summer has arrived.

The hotter it gets, the faster the mosquitoes complete their life cycle and the more mosquitoes we'll see around.

We've already seen big numbers of mosquitoes in some areas and, unfortunately, I think that's probably going to continue all the way through summer.

This is general information only. For detailed personal advice, you should see a qualified medical practitioner who knows your medical history.