Mosquito Bites 101

Scratching out the itch with facts

Mosquito bites might not be completely avoidable, but there are some things you can do to reduce your risk. Not only will taking these precautions make dealing with a mosquito bite less frequent and annoying, but also much safer. Mosquitoes carry many diseases that they can transmit to humans. So before you head out to enjoy the fresh air, arm yourself with intel.

Why do mosquitoes bite?

You may think mosquitoes only exist to feed off of humans. This is wrong on many levels. Only a small percentage of mosquitoes primarily bite people. Mammals, birds, amphibians and reptiles are their typical prey. Further, mosquitoes don’t bite to live, but rather, to reproduce more efficiently (they live off of nectar and plant juices). This means that only female mosquitoes bite. The female uses this blood as a nutritional source for an amino acid called isoleucine. Mosquitoes use isoleucine to produce eggs, specifically, more eggs. If a female mosquito doesn’t find any isoleucine, she can only lay as few as 10 eggs. But if she finds prey to suck blood from, she can lay as many as 100.

What causes mosquitoes to bite you?

With a variety of hosts to choose from, mosquitoes have developed a number of senses to help them pick their next victim. While body heat, odor and movement all play a role, it’s the scent of carbon dioxide and chemicals in your sweat which draw them to you. Truth be told, human blood is an inferior source of isoleucine compared to rats and buffalo – humans just happen to outnumber buffalo and are easier to attack than rats.

What happens when a mosquito bites you?

When a mosquito picks you as her next victim, she typically lands on exposed skin (though she can bite through light clothing). Her mouth is long and tubular, allowing her to pierce through your skin and siphon blood out. After stabbing through the skin with her ‟feeding stylets,” she searches for a blood vessel, which typically takes less than 60 seconds. To keep the feeding quick and blood from clotting, she injects specialized saliva into your body. This continues until the mosquito has had enough, or roughly, four times her body weight in blood.

Why do mosquito bites itch?

When a mosquito bites you, a few things happen. For starters, the mosquito uses her (all mosquitoes that bite are female) feeding stylets to pierce your skin. The stylet consists of a pair of maxillae and a pair of mandibles. Once she breaks through your skin, the mosquito quickly searches for a blood vessel, and then begins the blood siphoning process. Mosquitoes can suck your blood with such force that tiny blood vessels collapse or rupture. At the same time your blood is pumping out of your body, the mosquito pumps saliva in.

This saliva acts as an anticoagulant, which prevents your blood from clotting at the site of the puncture. This allows the mosquito to feed quickly, giving her a better chance of stealing away with your blood before you notice and splat her on your arm. This saliva is specifically why mosquito bites itch – you have an allergic reaction to it, resulting in the telltale bump and itching associated with mosquito bites.

The science behind what causes mosquito bites to itch

The mosquito saliva flows into your body through one tube (the hypopharynx), while another tube (the labrum) is used for pumping your blood up to the waiting mosquito. The saliva contains enzymes and proteins that bypass your body’s natural coagulation system. These anticoagulants – along with up to 19 other enzymes and proteins – directly cause the allergic reaction in your body.

Your body’s immune system responds to these allergens by releasing histamines. Some scientists believe that your very first mosquito bite introduced these allergens to your body and sensitized you to the components of the saliva. This sensitization is responsible for your body sending immunoglobulins to the mosquito bite. Immunoglobulins break down connective tissue and mast cells, which actually release the histamines that make you itch. Mast cells help heal wounds and defend against pathogens, but they play a big part in allergic reactions and inflammation. The histamines they release are commonly combated with antihistamines, which work to stop the itch.

New research points to a more complicated response from the body that includes a ‟histamine-independent peripheral pathway.” This involves mast cells as well, but theorizes that substances other than histamines are released, which then cause peripheral neurons to signal the central nervous system (CNS). The CNS interprets these signals and sends them to the brain, which lets you know that the bite itches.

What does a mosquito bite look like?

Unlike bed bug bites or other insect bites that take a while to show up, mosquito bites are almost always immediately noticeable. Though the appearance of a bite can vary from person to person, a mosquito bite will typically be inflamed, roundish and filled with fluid. The bite might have oddly shaped edges, rather than perfectly round ones. There also might be a small dot at the center. Multiple randomized bites in one area are not uncommon. A localized reaction can mean more swelling, redness and itching than usual. Children, people with an impaired immune system or those who are extremely allergic to the saliva may exhibit more severe symptoms.

What signs should you watch out for?

Between one and two million people around the world die from mosquito-borne diseases each year, according to the Prairie Research Institute of Illinois. Among these diseases, malaria is the most notorious, but in the United States, West Nile virus and mosquito-borne encephalitis are the most prevalent. A mosquito’s bite can also cause yellow fever, Chikungunya and dengue. If you or your loved ones have been bitten, watch for symptoms such as headaches, fevers, chills, body aches, stiffness, joint pain, confusion, swollen lymph glands, disorientation, weakness or skin rashes. If any of these occur, see your doctor right away.

How can you stop mosquito bites from itching?

Scratching mosquito bites can lead to secondary infection if you break the skin or reopen the bite. Dirt from under your nails is the culprit here, and can lead to staph, strep and other bacterial infections. To help prevent infection and stop the itch, Ohio State University recommends washing the area of the bite with soap and water. Use anti-itch cream, calamine lotion or antihistamines to lessen the itch. You can also use an ice pack to numb the area, thus negating the itch while reducing swelling. Aside from the warning symptoms listed above, if the swelling doesn’t start going down within a day or two, you have open sores or your eyes or joints become infected, see your doctor immediately.

How can you stop mosquitoes from biting you?

Mosquito bites aren’t always preventable, especially at dawn and dusk when the majority of mosquitoes are most active (some, like the dangerous Asian tiger mosquito, are active all day while others remain active all night). Cover exposed skin with long pants and sleeves. Wear a hat, a light scarf and work gloves if the weather allows. Mosquitoes can bite through light clothing, but if you bunch material, it keeps the mosquito away from your skin. Keep properly fitted screens on all windows of your home and be sure they are in good repair. Doorways should have tight seals and doors shouldn’t be left open. You can use mosquito netting on strollers, playpens, beds and even your own head with a mosquito hat. Screened in porches are a great way to enjoy the outdoors while protecting your family from the itch and disease of mosquito bites. Outdoors, make sure there is no untreated standing water anywhere on or around your property. Of course, a mosquito repellent that contains DEET is essential, especially if you plan to spend any amount of time outside, particularly in the woods or other natural habitats of mosquitoes. Be sure to follow all instructions and warnings on the label.

For homes that have large mosquito populations, other measures might be necessary such as removing hidden mosquito breeding grounds, applying residual sprays and other methods employed by pest management professionals. Don’t spend your summer scratching mosquito bites. Call Terminix® so we can scratch that problem off your list.