Summer is the season of mosquitoes. And mosquito bites can itch like nothing else. And once you start scratching, it's hard to stop. Show
"It is the female mosquitoes that bite, and there is some saliva that enters the skin while the mosquito is feasting on its blood meal," said Amy Kassouf, MD, a dermatologist at the Cleveland Clinic. "This is the protein that causes the allergic reaction—and itching," Dr. Kassouf explained. Basically, our immune systems see the protein as an enemy invader. "The proteins in the saliva are foreign to your body and cause an immune system response," said Dawn Davis, MD, a dermatologist at the Mayo Clinic in Rochester, Minnesota. "This causes irritation and the local reaction we see as the bug bite," added Dr. Davis. Our bodies are just particularly sensitive to mosquito bites. Other bugs bite may not have the same impact on your immune system, Dr. Kassouf explained. For example, stings bees and wasps are likely to produce more pain than itching. Scratching a mosquito bite is a double-edged sword—it feels so good for a few seconds, but it also makes the itch sensation way worse. "When you scratch, you may release more local histamine—the chemical in the skin that causes the swelling and itching—and you may also be spreading the allergen under the skin," said Dr. Kassouf. If you tend to scratch until you bleed, you're putting yourself at risk for skin infections. "Scratching a bite opens up the skin, making it more painful or itchy and potentially causing bacterial infections like pyoderma, impetigo, or even cellulitis," cautioned Joaquin C. Brieva, MD, a dermatologist at Northwestern Medicine in Chicago. You're not imagining it—mosquito bites do itch more at night. "Most people itch more at night because our cortisol levels (our bodies' own anti-inflammatory hormone) are higher in the morning, and also because we are less distracted as we wind down and try to fall asleep," said Dr. Kassouf. You probably have that friend that gets eaten alive every time they are outside. There are a few reasons why that may be. Some people may be more prone to get bug bites based on several factors:
And a person's blood type could be to blame. A research study published in 2022 in the journal Scientific Reports found that some types of mosquitos have a preference for feeding on blood type B. The researchers also found that female mosquitos feeding on blood type B lay the highest number of eggs, followed by blood type AB, and blood type O. If you've ever wondered why some mosquito bites itch more than others, it totally depends on your body. "Everyone responds differently to mosquito bites," said Edidiong Kaminska, MD, a dermatologist at Northwestern Medicine in Chicago. While some people may have a minimal reaction, others may experience blisters and extreme swelling. But the most common reaction is simply red, itchy, swollen bumps. Your reaction depends on your body's immune system. "Reactivity is based on the sensitivity of one's immune system to the bite," Dr. Davis explained. But some people are prone to develop the big whoppers. "People with atopic traits—eczema, asthma, allergic rhinitis—tend to develop more severe local reactions after mosquito bites," explained Dr. Brieva.
Mosquito bites are small, raised bumps on the skin that come from a female mosquito feeding on human blood. Mosquitoes are small, flying insects known as vectors (living things that carry diseases between animals and humans). Vectors often carry infections through blood.
A mosquito bite featuring a raised bump and a dark spot in the center. Mosquito bites are small, raised bumps on the skin resulting from a female mosquito feeding on human blood. Mosquitoes are small, flying insects. They have six legs and long mouthparts — used to feed on blood and nectar. Only female mosquitoes feed off of blood. Three different types of mosquitoes exist in various parts of the world: Aedes, Culex and Anopheles. Often, mosquito bites don’t cause any lasting harm. They cause mild annoyance and irritation for a short period. However, mosquitoes are dangerous because they spread diseases that can be fatal. Where are mosquitoes found?Mosquitoes are often near water. They lay their eggs in shallow, stagnant water. The eggs are usually in marshes, ponds, lakes, children’s pools, the inside of tires, birdbaths and other containers with shallow water. Why do mosquitoes bite?Mosquitoes bite and suck blood for reproduction. Though male mosquitoes only eat flower nectar, female mosquitoes eat both flower nectar and blood. The females need the protein in blood to develop eggs. What happens when a mosquito bites you?Mosquitos have a long mouthpart (proboscis) that extends far beyond their heads. It looks like a tiny needle. When a mosquito bites you, it uses this mouthpart to pierce your skin, suck your blood and secrete saliva into your bloodstream. Why do mosquito bites itch?When a mosquito secretes saliva into your bloodstream, your body registers the saliva as an allergen. Your immune system then sends the chemical histamine to the area where the mosquito bit you to remove the allergen from your body. Histamine is what causes your mosquito bites to itch and swell. Most people have a mosquito bite allergy. How do mosquitoes spread disease?Mosquitoes spread disease through their bites. Mosquitoes are vectors (living things that carry diseases between animals and humans). Vectors often carry infections through blood. Many of the creatures classified as vectors are bloodsuckers. Other vectors include ticks, fleas and sandflies. When a mosquito bites, it not only sucks blood but secretes saliva. This saliva enters your blood. There is an exchange of fluids between the mosquito and your bloodstream. An infected mosquito has fed off a person or animal with the disease. It then passes the infection on when it bites. Mosquitoes often feed in a method called sip feeding. Sip feeding means that the mosquito doesn’t just suck all of the blood it needs from one source — it takes multiple meals from multiple sources. Unfortunately, this exposes more people to infection. What types of diseases can be spread by mosquito bites?
Who is at risk of being bitten by mosquitoes?Mosquitoes bite anyone. However, some factors might prompt mosquito bites. These include:
After a female mosquito bites you, a small, raised bump forms. The raised bump may change colors, and you can sometimes see a small, dark spot in the center. That dark spot is where the bite occurred. What causes a mosquito bite?Mosquito bites are the result of a bite by a female mosquito. Male mosquitoes don’t bite. A female mosquito doesn’t necessarily bite you, but instead sucks blood as a part of their diet. The skin around this area is irritated, and a circular bump appears on the skin. What are the symptoms of a mosquito bite?The symptoms of a mosquito bite can vary. If the mosquito has a disease or an allergic reaction occurs, the symptoms could be more severe. The common symptoms include:
More severe symptoms can include:
Mosquito bites typically don’t need treatment. Topical mosquito bite creams can relieve itchy skin and discomfort. However, see your healthcare provider if more severe symptoms develop after a bite (allergic reaction, fever, headache or body aches). Also, see a healthcare provider if you experience symptoms and have recently visited a place where mosquito-spread infections are common. Treatment will vary depending on the type and severity of the infection. How do I stop mosquito bites from itching?Don’t scratch your mosquito bites. You risk breaking your skin and exposing yourself to infection. If you accidentally break your skin, keep the area clean by washing it with soap and water and covering your mosquito bites with a bandage. Talk to your healthcare provider if you have an infected mosquito bite. Mosquito bites only last a few days. However, there are many over-the-counter products or home remedies that can stop mosquito bites from itching. While home remedies are safe for most people, it’s a good idea to check with your healthcare provider before trying some of the following options to get rid of your mosquito bites. You may be at risk of developing an allergic reaction on your skin.
You can prevent mosquito bites in several ways. These include:
When visiting an area with an active mosquito-carried disease, it’s important to follow safety guidelines. It can be dangerous to travel to areas with active mosquito-carried diseases when pregnant. Transmission of the Zika virus to a pregnant woman can impact the fetus (possibly causing birth defects). The virus can also spread through sexual contact. It’s important to protect yourself and your partner if you’ve traveled to a region with Zika. Bed bug bites vs. mosquito bitesLike mosquitoes, bed bugs feed off your blood and secrete saliva into your bloodstream. Bed bug bites look similar to mosquito bites. However, bed bug bites often exhibit a distinct line or zigzag pattern. Bed bugs are active at night, and they’ll bite your exposed skin while you’re sleeping, including your face, hands, arms, feet and legs. If you’re suffering from bug bites over a long period, your healthcare provider can help you identify the type of bite. Flea bites vs. mosquito bitesFleas also feed off your blood and secrete saliva into your bloodstream. Flea bites look similar to mosquito bites and bed bug bites. Fleas travel by jumping, so their bites appear more random than bed bug and mosquito bites. You’re more likely to experience flea bites if you have dogs, cats or another pet that spends time outside. If you’re suffering from bug bites over a long period, your healthcare provider can help you identify the type of bite.
You should see a healthcare provider if you experience an allergic reaction to a mosquito bite or develop symptoms of a disease carried by mosquitoes. If you’ve visited a region with active mosquito-transmitted diseases and develop symptoms, see your healthcare provider. A note from Cleveland Clinic Mosquito bites are an itchy, pesky reality when the weather is hot. In most cases, mosquito bites are ultimately harmless. But you shouldn’t scratch mosquito bites. You can relieve your itch with many over-the-counter or home remedies. Contact your healthcare provider if your bites last longer than a few days, continue to grow in number or if you develop an allergic reaction.
Last reviewed by a Cleveland Clinic medical professional on 10/15/2021. References
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy |