Mosquitos live for only a few weeks, but in that time, they can do a lot of damage. The mosquito is considered the world’s deadliest animal, killing more people per year than any other creature, largely due to their ability to spread malaria.
Malaria isn’t a concern in the United States, but the country is home to about 12 types of mosquitos that spread disease, including West Nile and dengue. However, most of the 200 species of mosquitos in the United States are known as nuisance mosquitos—their bite will bother you, but it won’t cause serious illness.
If you’ve ever had a mosquito bite, though, you know that it can feel like more than a mere nuisance. The itch can be intense.
“Mosquitos have proteins in their saliva, and when these come in contact with our skin, the body sees them as allergens and triggers an immune response,” says UNC Health family medicine physician Liza Straub, MD. “The body releases histamine, and that’s what causes the bite to itch.”
Dr. Straub explains how to prevent mosquito bites and how to treat them.
Preventing Mosquito Bites
You can prevent mosquito bites by staying indoors when mosquitos are most active and by keeping outdoor spaces free of standing water.
“Most mosquitos are out and feeding at dawn and dusk,” Dr. Straub says. “Standing water is a mosquito breeding ground, so if you have things like water tables for your kids or wheelbarrows, dump the water and don’t keep those in the yard.”
Mosquitos can bite at any time of day, so when you are outside, try to minimize exposed skin by wearing pants and long sleeves. You can buy repellent-treated clothing or make your own by applying permethrin to your clothes. Permethrin should not be applied directly to the skin; look for an EPA-approved insect repellent for that purpose.
“The most effective insect repellent ingredients are DEET and picaridin,” Dr. Straub says. “The higher the concentration of the ingredient, the longer it will last, so check the label.”
Insect repellent is safe for children when used as directed, but use it sparingly. For infants, Dr. Straub recommends using netting over strollers to prevent bites.
If you’re traveling internationally, check the Travelers’ Health website maintained by the Centers for Disease Control and Prevention to see if your destination has any advisories related to mosquito-borne illness. You may need vaccines or medications before travel, in addition to taking precautions to avoid bites.
Treating Mosquito Bites at Home
If you do get bit by a mosquito, you’ll likely see a reddish bump emerge—or you’ll notice the itch. Try not to give into the impulse to scratch.
“Scratching can break the skin and expose you to bacteria and a secondary infection,” Dr. Straub says. “Use a cold compress to decrease the itchy reaction and put a bandage on the bite so you won’t scratch.”
Dr. Straub recommends using the cold compress or ice instead of over-the-counter anti-itch creams or lotions.
“In general, I don’t recommend topical diphenhydramine (Benadryl) or benzocaine ,” she says. Those products can irritate the skin, and if people are allergic to them, they may have a secondary allergic reaction.
If you do want to try an over-the-counter product, Dr. Straub recommends looking for the ingredients pramoxine, camphor or menthol, which are more effective at decreasing itch with a lower risk of skin reactions. Taking a non-drowsy antihistamine such as cetirizine (Zyrtec) can also help.
The CDC recommends a paste of one tablespoon baking soda and water, applied for 10 minutes, for reducing the itch.
Dr. Straub says mosquito bites look and feel similar to bites from gnats and biting flies, and the treatment is the same—use a cold compress and don’t scratch. If you see a line or cluster of bites, it’s possible you might have been bit by fleas or bed bugs, which will require taking action to remove those from your home.
When to See a Doctor for a Mosquito Bite
Most bites stop itching and go away within a few days. If your bite shows signs of an infection, such as redness, swelling, feeling warm to the touch, increasing in size or becoming painful, you should call your doctor, visit urgent care or use virtual care.
If you experience flu-like symptoms after a bite, or if you’ve traveled internationally and got bit, you may want to ask your doctor about your risk for mosquito-borne illness.
It is possible, though not common, to have a more pronounced allergic reaction to a bite.
“Very rarely, mosquito bites can cause large local reactions instead of small bumps,” Dr. Straub says. “You might have hives all over or a big area of redness that’s really warm or itchy. In young kids, it might cover a whole arm or leg.”
Your doctor may treat these larger reactions with oral steroids.
While most people don’t require medical treatment for bites, Dr. Straub says to call your doctor if you’re concerned about how you feel afterward.
“It can be difficult to figure out by yourself if you’re having a larger reaction to a bite or a secondary bacterial infection,” she says. “Your doctor will be able to treat it appropriately.”
Worried about a bug bite? Talk to your doctor. If you need a doctor, find one near you.