Tired of Mosquito Bites? Why They Itch and What to Do About It

Written by Chem-Wise on . Posted in Blog

Summer can be truly beautiful. You probably love sitting outside during the evening when the sun goes down, the air cools off, and people are out and about-but the mosquitoes like summer evenings too.

By now, you’ve probably been bitten a few times, and you’re tired of dealing with the itchy red bumps. As you scratch away in frustration, you may have a few questions. Why do mosquito bites itch so much? Why do they get bigger when scratched? And how can I lessen the itching? This blog can give you the answers.

Why Do Mosquito Bites Itch?

When a female mosquito (males don’t bite) feeds on you, she inserts her proboscis (or needle-like mouth) into your skin to draw blood. However, blood has platelets that form clots over cuts and scratches. If a clot forms around the bite, the mosquito could get trapped.

To make sure they don’t get caught, mosquitoes inject a little of their saliva into the person they bite. The saliva contains an anticoagulant, and this substance prevents clots from forming.

By injecting this mixture, the mosquito gets to feed on your blood and get away with it. However, exposure to the anticoagulant is not so great for you. Your immune system recognizes the foreign anticoagulant and fights off the “invader” by releasing histamine.

Histamine causes the bitten area to swell up with extra blood (extra blood means extra white blood cells, which fight off germs and aid in healing), and it also causes the area to get irritated and itch, just like how your eyes itch when they get pollen in them. The result is the itchy red bump you know all too well.

However, some lucky people don’t react to mosquito bites, or they rarely react at all. In areas with lots of mosquitoes, some people have been bitten so many times that their immune systems stop reacting and just accept the bite as normal. In that case, the bite will not itch or swell, and the person may never know they were bitten.

If that person travels to an area with a different species of mosquitoes, though, the bites will contain a different anticoagulant. That person will again get the itchy bites the rest of us suffer from.

Why Do Mosquito Bites Get Bigger When Scratched?

Probably the worst thing about mosquito bites is that if you scratch them, they get bigger and last longer. You can only let them heal if you ignore the itching.

The bite marks get bigger when scratched because of your immune system’s response. As previously mentioned, the area swells in an attempt to get rid of anything that could harm your body. If you scratch it, you’ll irritate the area more, convincing your body that the problem is getting worse instead of going away, so the immune system will release more histamine instead of less. The area gets bigger as a result.

You have to let your body calm down by ignoring the bite if you want it to go away.

How Can I Treat Itchy Mosquito Bites?

To soothe your body’s response, you can try various lotions or salves, including:

  • Hydrocortisone cream. Hydrocortisone contains a mild steroid that reduces inflammation and swelling. Essentially, it reduces your immune system’s reaction. You can find a tube of it in most drugstores for a few dollars.
  • Cold. Numbing the area can provide some temporary relief. Take a cold shower if you have bites all over your body, or use an ice pack to numb just one or two bites.
  • Protection. If you worry that you’ll scratch a bite no matter what, cover it so you can’t get to it. A Band-Aid or some tape might do the trick. Additionally, some people say that the pressure feels good on the bite.
  • Baking soda. Some people swear by baking soda. Make a paste with baking soda and water, and spread it on your bite. Similarly, toothpaste (many of which contain baking soda) may get the job done.
  • TUMS. If you have these antacids on hand, they can also be crushed and made into a paste that many users have found effective at relieving itchiness.

If all else fails, you may have to rely on simple measures like using distractions and willpower. You should be rid of that itchy bite in a day or two if you leave it alone.


If you’re sick of mosquitoes getting into your yard, you may have a pest control problem. Calling in an expert can help. Call Chem-Wise Ecological Pest Management to get started. We can answer your questions, assess your property, eliminate mosquito breeding areas, and treat existing mosquito infestations.

With our help, you can get back to enjoying your summer evenings without worrying about mosquitoes and getting bug bites. Enjoy sitting on your porch!