Fact Checked

Why do Mosquito Bites Itch?

Tricia Christensen
Tricia Christensen
Tricia Christensen
Tricia Christensen

Mosquitoes are a bit like flying syringes. Their large needle nose, called a proboscis, is ideal for quickly landing on a victim, withdrawing a bit of blood and then taking off for the next target. Individuals may not notice a mosquito bite initially, but within an hour or two after a bite, they may have raised red bumps that itch like crazy. When a mosquito bites, she leaves behind saliva that the body reacts to, causing a (usually) mild allergic response in the form of itchiness.

The saliva that a mosquito leaves serves the insect well, since it works as an anti-coagulant. These means the mosquito can quickly draw blood without catching a person's attention. The saliva causes the body to produce a histamine response, so the skin around the bite area gets itchy.

Mosquito about to bite.
Mosquito about to bite.

The itchiness of a bite can actually be a good thing, even if it's an annoying one, because mosquito bites can transfer disease. In the US, risk of West Nile Virus is the main concern. In other countries, mosquitoes may transfer malaria and other serious germs. If people's bodies didn't respond with the itch factor, they might not realize they'd been bitten. Though knowing that they've been bitten may not prevent the spread of disease, it does make them aware of a possible cause should they develop severe flu symptoms a few days or weeks later.

A mosquito net around your bed is one of the best ways to prevent bites.
A mosquito net around your bed is one of the best ways to prevent bites.

Some people build up a tolerance to mosquito bites. They may barely notice when they've been bitten, and the skin may not swell up. This is sort of like getting allergy shots, where the small doses of saliva over time can cause the person to become immune to it. Adults more typically have less of a reaction to bites than do children. This immunity can wear off after a while, and an adult who hasn't been bitten for a few years might become itchy again after receiving a few new bites.

mosquito with a blood filled abdomen.
mosquito with a blood filled abdomen.

Other people may have strong allergic reactions to mosquitoes, although these are not usually anaphylactic shock reactions, like those caused by bee venom in people allergic to bees. Instead, the skin may develop blisters, bruises, or scabs. A child who has an allergic reaction can look almost like he or she has a case of chicken pox. It can help people with extremely itchy bites to use oral antihistamines or topical antihistamine creams on them. People who have a lot of bites and swelling should be watched for possible infection of the sites.

Allergic reactions to mosquitos may lead to bruising.
Allergic reactions to mosquitos may lead to bruising.

Since mosquito bites can cause more than an itch, it's a good idea for people to avoid them when they can. Mosquitoes are most active during the hours just before and after sunrise and sundown. Individuals may also find that it can help to wear protective clothing — though some mosquitoes can drill right through clothing — and insect repellent if they are in areas with large mosquito populations. Screening windows and keeping doors shut can also keep mosquitoes out of a home.

Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent TheHealthBoard contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent TheHealthBoard contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

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Discussion Comments


Thanks for sharing the best mosquito bites solutions. Almost immediately after a mosquito bites you, you may notice around and puffy bump forming. In some cases, you may see a small dot at the center of it.


No matter how strange it might seem, post no. 66 really did help. Thanks a lot!


There is something to the "sweet blood". I'm diabetic and if my sugar isn't well controlled, I get a lot of mosquito bites. Cut way down on the carbs and you'll get bitten less.


I hate mosquito bites! They're the worst! I hate the fact that I can never feel them bite me so they basically get away with it. I know I'm delicious, but damn!


I've got a lot of mosquitoes around my garden and I get bitten like five times and more daily. Most of them are aedes, but so far I've had no sign of sickness.

I wonder if I've become immune to them or if something worse is going to happen in the distant future.


The mosquito bite itches because when it stings it makes your blood rush quicker (I know you already know that) and if your body can't stop that you will die so your body has a special kind of fluid or something which stops the blood from rushing too quickly and saves you from dying, but it makes you itch. The swelling part I don't know about, but would you rather die or itch?


@Jessica123: The pattern of bites you are describing sound a lot more like bed bugs or something like that. I believe bed bugs have common areas they bite, and common places that you'll find bed bug rashes (a series of bed bug bites). All those areas (armpits, toes, certain places around the scalp) all sound like bed bugs, and not very much like Mosquitoes as I think Mosquitoes would have a hard time biting you enough to create rashes or patches and in some of those areas, like the armpit and your toes.

Could this be the case? If you're unsure at all that they're caused by mosquitoes I would show them to a doctor.

If they are mosquitoes, I have no clue about sweet blood. I would think that something in your blood/sweat is attracting them more than the average person. But I'll let you research that.


Because the saliva gets spread around which makes it more itchy and enlarges its size. Which is why many people say not to scratch it.


Why do the bites get bigger when you scratch them? Makes no sense.

I have one on my hand, so when I woke up (like right now) I looked and noticed it doubled in size.


I always scratch until I break skin at the top of the bump, and then I squeeze all the stuff (which is just clear liquid) out of the bump until it's basically no longer a bump, and it works so well for me. Relief comes instantly after that, and i know that there's no more (what I call) bug juice in there anymore.


Saliva! Yep, I know it may sound gross but it's not bad. You just put some of your own(or someone else's if you wish) saliva on your finger and rub it directly on the bite, let it air dry and the itch is gone. You can spit directly on it if you like and then just rub it around over the bite but put enough saliva on it to make it completely wet. Like I said, let it air dry and the itch will be gone. Well, at least it works for me and everyone I've told about it. I haven't heard of it not working yet.


I eat candy sometimes (whenever I feel like it) and the problem is i get a lot of mosquito bites. A lot. Like once i had a lot underneath my right arm surrounding my armpit. There were lots of dots (bites) and they were red and very itchy but they've healed already. Sometimes i get them on my butt, which is really annoying when i am in public and it itches. i get them on my toes, ears, forehead --everywhere. and do they bite me because i have sweet blood? if yes, then how can i stop from having sweet blood? Like, i hate mosquitoes but they love me. I would appreciate it if someone answered this and what can i do to stop it from itching? I really want someone to answer me. I'd really appreciate it.


I found that at the Dollar Tree, they sell a cheap brand of anti-itch cream. It works really well. Although at first it burns, like a cold kind of burn, I guess, but it works so much better than the expensive Aloe Vera stuff. I live in Florida, right by the equator, so I would know. I have never gotten over 30 mosquito bites at one time, though, so I find over 200 in one night a bit strange. By the way, mosquitoes love bananas, so don't eat them while camping.


We have found a product in Europe called Aspivenin which works very well to remove the contents of bites and stings and the relief is immediate. I think it's available throughout the world.


whenever mosquitoes bite me on my face, they leave something white in there. After a day or so it swells up and I see the white stuff in the raised zit. If I try to squeeze it out it swells even more and itches like crazy and gets more white stuff that refuses to go away even after two weeks or so.

If I don't squeeze it, the stuff will dry, but it leaves something like a pupa in my skin. Now when ever I get bitten I dab a Q-tip in rubbing alcohol and push it against the bite and it seems to help the zit from getting big.


thanks for the help on my science project!


I got bitten by a mosquito in Perth on the ankle. Ankle swelled, couldn't walk. Spent four days with it elevated and a rather worried Doctor put me on high strength antibiotics.

Last week, I ate my lunch (around 1:30 p.m.) in a park in New Zealand and got bitten on the right fore-arm, left elbow and top back of right arm - all within 15 minutes of sitting under a tree!

My arm (24 hours later) has swelled with around a 20cm diameter circle around the bite, my elbow is twice the size it was and the other bite has developed into a blister.

I react badly to bites. I wash and clean every bite I get. Some swell a small amount, some swell a huge amount. I've had it for 10 years now (being almost 40 now). I do a lot to make sure my bites never get infected but the swelling is large with me. I am fed up with it!


Paraderm cream from a pharmacy seems to work!


I'm from Bangladesh. We have plenty of mosquitoes here as it is tropical country with lots of water-sources. Mosquitoes use still-water to lay eggs. So, we need to destroy their sources where they lay eggs. Frogs and fishes eat mosquito-larva. So we should not kill frogs and fishes.

Here in Bangladesh, we call ''Mosha'' for ''Mosquito''. Most Bangladeshi people have immunity for mosquito bites. But we have Dengue, Malaria and other diseases. Mosquitoes are the main reason.

If mosquitoes bite you, don't panic. Put some of your own saliva on the bite. It will help you. If it doesn't work then wash your bite area with hot water and antiseptic soap or bleaching powder. If that doesn't work then put some drops of Savlon or Dettol in a pot or mug. Put some hot water in that mug. Just wash the area (where the bite is) with that hot water. After that apply 2 or 3 drops aftershave lotion on the bite. It will work. It will stop the itchy feelings.

If it doesn't work then you may use white vinegar or whiskey or mild spirit on the bite.

You may also put salt in hot water and then you apply it on bite. Heat is good for the bite. But you may also need some chemical to remove the allergic itch.

You may use sap of an onion on your bite. Just cut an onion and use the sap on your bite directly. It will help.

If doesn't work then you may also try lime or lemon on bite. Citric acid can help to stop your itchy feelings.

If that doesn't work, try hydrogen peroxide.

To stop itchy feelings, you may also apply a cube of ice on the bite. And you can put some minty cream or balm on it. Eucalyptus oil is good to use.

These are actually primary treatments. But you must go to the doctor if you feel bad or if you get any flu or fever.

If you're allergic then you may have antihistamine tablets. But you must consult with your doctor. You may also put antihistamine cream on you bite. If you have an infection, then you probably need an antibiotic.

I heard that people who take ganja or smoke ganja, mosquitoes don't bite them. I don't know whether it is true or not. But I have read online that the Tharu ethnic people of North India and Nepal have immunity to prevent Malaria and Dengue Fever.

I noticed that mosquitoes love to bite the British people more. I have a British friend. He came to Bangladesh to visit last year. And he got more than 200 bites. He was very allergic and the bites were too red and big. And those bites became sores.

I also noticed that mosquitoes bite me more than my other family members and friends. I'm not allergic. But my skin is sensitive.

Here in Bangladesh, we use insect killer spray or aerosol, mosquito killer coil, Dhup-dhuno, Good Knight Mosquito Killer, Morton etc. etc.

We have a racket like electric device to kill mosquitoes here in Bangladesh. We also use mosquito repellent spray or cream. We also use mosquito curtains on our beds to protect mosquitoes from biting us at night.


Thank you post #66! Heat worked! I was going crazy - the bites were so itchy and hurting and I couldn't get any relief. I tried Ibuprofen, Tylenol, Neosporin pain reliever; dermoplast anti-itch; seabreeze; warm salt water. I was going bananas. They were so itchy I couldn't stand it!

Then I read #66 post that heat works. I heated my microwaveable bead bag that I use for muscle relief and you would not believe it. After 10 minutes, I was feeling better. Reheated it and in 10 minutes all pain and itchiness gone! Thank you post #66!


Heat, people. Heat! Heat destroys the proteins injected by the bug, which makes the bite itch. Best method: (a) Fill a ceramic coffee mug halfway with water, (b) heat in microwave for a minute or so (don't need to boil it), (c) put a towel over the bite (so the mug doesn't contact your skin), and (d) hold the hot mug against the area of the bite for at least 1-2 minutes. **Caution: Don't burn yourself! Hold it there at short intervals, or as long as you can stand (up to 10 seconds at a time?) until the total heating time is approx. 1.5 minutes.

* If it still itches, apply the heat 30-60 seconds longer at short intervals. I've used this method on at least 10-12 occasions, and it works every time. It will make you appreciate the wonder of chemistry, physics and biology!


If you put cinnamon toothpaste on it it stings a lot but it does help.


I have 40 mosquito bites on one arm. How can I make the swelling go down?


I was at a soccer game two nights ago and got two bites. one right between my eye and one on my cheek. the one on my cheek is small and not itchy or red, but the one on my forehead is big, red, and so itchy. what should i do for it? school starts in two days and I want it to go down and not be noticeable.


I got bit by a mosquito four weeks ago. Two of the bites, one on my ankle the other on my elbow, healed up then started to raise, and got red and very itchy again. Why is this?


I have two of them on my arm above my elbow and on my ankle. the ankle one is OK but the one on my arm itches. Seriously, i read online to use your fingernail and put an X on the bite. i still have the X on it now and it doesn't itch at all. it said it will last at least until you find a real solution.


You can also use this product called "Hydrocortisone 1 percent", an intensive healing formula (maximum strength).

I got a bug bite on my arm, so I got a bottle of it the other day, and man, it works. It doesn't irritate, and about 25 minutes later the swelling decreased to half of what it looked when I got it.

I would recommend it to anybody, and with any kind of bite, regardless where you were bitten. Period. And it does serve other purposes than as an anti-itch cream.


Dab a cotton ball with bleach and rub on the bite. It will stop the itching right away! Of course you can bleach a lot of furniture and clothing that way, but you will not itch!


you people are crazy opening up a mosquito bite. Don't do that. Putting clothing over the bite seems to work the best to get rid of the itchiness for me.


Right now I have seven mosquito bites! Seven!

One on my nose, eyebrow, left leg, left shoulder, left side of my chest (I'm a girl. Maybe that was a perverted mosquito, that is a girl?), right side of my stomach, and my left thumb!


is everybody allergic to mosquito bites?


@ 40: Only female mosquitoes bite. Females need the proteins in blood to produce fertile eggs. Males don't need these proteins.


"I woke up the next morning with 202 new bites. I don't understand why I got so many if my friends only got one or two."

I don't understand why you counted them.


Just the other day I was sitting outside with some friends at around 10 pm and I woke up the next morning with 202 new bites. I don't understand why I got so many if my friends only got one or two.


Awhile back I got a mosquito bite on my hand. (Bear in mind I'm a security officer at a construction site). Everyone of the construction workers can vouch for me that they saw my hand swell up in three days like a baseball glove.

I went to the ER and the doctor gave me an antibiotic, the swelling went down and I thought I was okay.

Now, I have a new bite below my shoulder that is itchy, swelled up, warm and quite uncomfortable. I put Aloe Vera on it hoping it may go down soon like the other ones did on my back. I just don't want another trip to the ER.


I just came to a different country two days ago (for vacation and seeing my family) but i got 21 mosquito bites the first day. Nobody else got bit as much as me and it's freaking itchy. they're also huge and i can't stop freaking scratching them!

i don't have an allergic reaction or whatever everybody else was saying and i don't plan on doing some of the stuff the others were saying. But, since the place I'm in isn't like the US, i don't have most of the stuff used to help relieve or take away the bites. Please tell me what would help if you were in my situation!


dr tichenor's soothes the itch well.


Mosquito bites really affect me. I often get blisters or scabs from them. I have taken oral antihistamines on countless occasions but seem to be sensitive to them and get extremely tired within 20 minutes or so of taking them. The antihistamine creams don't seem that effective. suggestions?


In answer to anon94116: Because it is she who does the biting and feeding. In fact, she needs blood, or rather a certain amino-acid found in blood which allows her to produce and lay her eggs.


Why is the mosquito labeled a she?


i got 20 (to be exact) mosquito bites today.

i actually was able to kill the one that bit me before and i saw my blood on my wall. I *hate* mosquitoes.


I get bitten very often and I use anything minty to cool it off, for example, vicks, bengay, tiger balm and tooth paste if you have none of other stuff. Also I recommend you rub it in for a bit. This really works out for me. Hopefully this helps you guys.


well these bites are so annoying! my nephews are extremely allergic to mosquito bites. when they get bitten the marks are usually huge turn a purplish greenish color and pus right up. it's quite gross and sad at the same time. we have to load them up with bug spray.


i got bitten by a mosquito on my left butt cheek, and how bad it really itches me. now there's the size of a quarter on my butt and it really hurts. If i put bleach on it will it stop the itching? someone help me! (tasha)


The sweeter the blood, the more delightful it seems to the mosquito. e.g. i love candy and sugar. I'm probably going to end up diabetic. Anyway, whenever me and my sister go out, I'm the one who always gets bitten, but never her. Jealous.


Also, why won't mosquitoes just get the heck away from my part of the world and go to Antarctica and freeze to death ?Because they like our blood! If those darn mosquitoes keep biting me I will spray them with the bug spray, and myself!


Mosquitoes are in our garden everywhere, and they love to bite me! They ignore my family, and bite me! Is it because of my big muscly thighs?


Answer to: if you are bitten on the tip of the penis, what should you do?

Wear underwear and pants. I've wandered around some of the most skeeter invested swamps and bottoms and never been bitten on the head of my penis!


them there skeeters can tell where you have blood close to the surface of the skin. So like an oil well, they go for the gusto by selecting prime areas like on neck, ears and ankles in which to drill. So try keeping those there areas covered up. And, I also saw on a TV show where a guy put some oil of Lemon Eucalyptus on uncovered skin and the skeeters wouldn't even come in for a landing on him.


Because I wear flip flops a lot I get mosquito bites on the tops of my feet, and then oh my gosh, when I have to wear shoes and socks to work (which I hate) my feet sweat and the bites start itching like crazy. It's almost unbearable and drives me mad.


just came back from camping for two days and have over 30 bites on me. Eight on my head and six on my right butt cheek alone.


I've squeezed them like a pimple before, hurts to do it lol but it does take the itch away. This clear liquid comes out. So it works. But it makes them take a long time to heal off your skin and sometimes leaves a scar


My whole arm swelled up from one mosquito bite. It took almost a month just for the whole swelling to calm down. That one bite turned into a big mutha lovin fat cover up jelly for my arm.


i have 16 bug bites on me, just from sitting on the sidewalk for five minutes. i have seven on my left leg, five on my right, three on my back, and one on my hand. Help!


I have six mosquito bites: three on my left leg, two on my right and one on my arm. They itch especially this one on my left leg. I have tried anti-itch cream but to no use. Please help!


I got bitten in the nose! Not normal! Someone help me!


i hate mosquito bites so much, they itch badly and mosquitos are especially attracted to me.


I have got about 9 mosquito bites on my legs and i was having a boiling hot shower my bites were not itchy at the time but then as soon as i put the hot water on they become very itchy. i changed it to cold water and it didn't itch very much at all and about 30 seconds later i didn't even know it was there.

When you scratch your bite, it causes friction and usually friction makes the skin hot and then it starts itching. so because of heat the mosquito bite hurts.


Hot water (as hot as you can bear) on the mosquito bite will relieve the itching.


thanks for the help. this really helps me with my science project!! =)


Try dabbing a little white vinegar on your mozzie bites. It provides some relief but it will sting a little, especially if you've broken the skin from itching.

The mosquitos in Australia are bloody huge at this time of year and vinegar has been working to stop them from itching. Or try 'Stingo's After-Insect Bite Gel.' As for the different sizes of bites I always just assumed the mozzie was bigger if the bite was bigger, but it could also depend on how big your blood vessels are where you were bitten, also maybe how much saliva the mozzie jabbed into you? Number of different reasons probably!


if you are bitten on the tip of the penis, what should you do?


Spray listerine mouthwash around the surfaces where you are. It keeps them away. True fact!


what would happen if you cut open your mosquito bites with a knife?


i have no reaction to mosquitos biting me and i never remember having a reaction. how long does it take to build immunity.


who discovered mosquitoes?


Itching from mosquito bites are common, and the size/irritation of the bite may vary depending on where it is located. It seems to sting a lot when somewhere on your hand.


What would happen if you tried to pop the bite like a pimple?


When i get bitten, some of my mosquito bites are small, then some are bigger. Why is this? Does the size of the bite vary because of the amount of blood taken out? Anyway please answer this! thanks!

Also, Anon17565, i don't think it's a good idea to break open up a mosquito bite... and add a chemical!


I got bit by a mosquito today and one bite is the size of my fist. The other bite is a little bigger than a silver dollar. Why are they so big?


If you open a mosquito bite, then put peroxide on it what would happen?


why are joint and muscle pain a sign and symptom of dengue fever?


when you get bites, is it bad if it itches and stings?

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    • Mosquito about to bite.
      Mosquito about to bite.
    • A mosquito net around your bed is one of the best ways to prevent bites.
      A mosquito net around your bed is one of the best ways to prevent bites.
    • mosquito with a blood filled abdomen.
      mosquito with a blood filled abdomen.
    • Allergic reactions to mosquitos may lead to bruising.
      By: PeJo
      Allergic reactions to mosquitos may lead to bruising.
    • Oral antihistamines can help reduce itching caused by mosquito bites.
      By: Wellford Tiller
      Oral antihistamines can help reduce itching caused by mosquito bites.