Summer means more time outdoors—and more opportunity for annoying critters to bite you. Most of the time, all you’ll get is a little red bump with itching and maybe a little swelling. These insect bite symptoms can be treated easily with anti-itch creams and over-the-counter antihistamines. Occasionally, bites can cause allergic reactions that lead to severe swelling and shortness of breath; if that happens to you this season, you need to be seen by a doctor.
Here’s your guide to identifying and dealing with summer insect bites.
There are thousands of types of spiders (technically arachnids and not insects) crawling around the U.S., but only two of them—the black widow and the brown recluse—can cause serious problems, and even those are rare. Most of the time you’ll see red bumps that hurt and itch if you’re bitten by a spider. Very few people get the severe pain and cramping of a widow bite or the decaying ulcers of a recluse bite (although if you do, get medical help right away).
Most spider bites are nonvenomous and can be treated at home. Wash the area with soap and water and apply an antibiotic ointment. Then rest, use a cold compress to reduce any pain and swelling, and elevate your arm or leg if that’s where you were bitten. Over-the-counter pain relievers and antihistamines can help as well.
Flies in the U.S. usually don’t transmit disease, but their bites can be savage. Horse and deer flies, for instance, have scissor-like mouths that will cut and tear your flesh. And although the flies aren’t venomous per se, some people do have allergic reactions to their saliva. These reactions need to be treated by a doctor.
Black flies also have a vicious bite and, if they appear en masse, can really hurt you. In rare cases, sand flies can pass on a skin disease called leishmaniasis, which can cause scarring on your skin. For the most part, though, flies are nuisances and their bites can be treated with oral and topical antihistamines.
Mosquitoes are infamous for spreading disease. Although most of the time you’ll just experience a red spot and itchy skin, mosquitoes feed on blood, and they can pass on various viruses including dengue, West Nile, Zika, yellow fever and malaria.
Anything that feeds on blood can spread illnesses, and “mosquitoes are your prime example,” says Rosmarie Kelly, a public health entomologist with the Georgia Department of Public Health in Atlanta. “Most are a nuisance, and some are more than that.”
People can have severe allergic reactions to mosquito bites, with hives, blisters, vomiting and difficulty breathing. If this happens, see a doctor. Also see a doctor if you have a fever, body aches, a headache or any other signs of infection after a bite.
Ticks are almost as famous as mosquitoes for spreading disease. In the U.S., ticks are responsible for passing Lyme disease, West Nile, Rocky Mountain spotted fever and tularemia to humans. The risk for each disease depends on geography; West Nile, for instance, is more common in the Northeast.
Most of these illnesses have common symptoms. “All tick diseases have classic flu-like symptoms and some have a rash,” says Kelly. “We tell people if they have a tick attached to themselves, they need to go to their doctor if they have flu-like symptoms within three weeks during tick season.”
Most tick bites can be treated with antibiotics, but they have to be correctly diagnosed first.
Fleas are the bane of cats and dogs, but humans can get them, too. You’ll see little red bumps if you’ve been bitten by fleas. Often, there will be three bumps together, usually on your feet and ankles.
It’s important not to scratch flea bites. The organisms defecate when they bite you; itching can pull bacteria into the skin and cause an infection.
Itching is the main symptom of flea bites, although if you’re allergic, you may have breathing problems. Infected bites swell and fill with pus.
Oral antihistamines or topical ointments or lotions can help with itching and allergic reactions. Lukewarm baths with an oatmeal solution might help, but don’t take hot showers or baths, which can worsen the itching.
Fleas are typically more of a nuisance than a health threat, but in some areas of the country, like New Mexico, they can transmit potentially life-threatening plague and hantavirus.
Bed bug bites
Bed bug bites are like the flu of the insect world: They spread like wildfire.
“They’re a huge problem because they’re good hitchhikers, and in some areas of the U.S., they’ve become a very large problem, first in hotels and now in apartments and multi-unit housing,” Kelly says.
They’re nuisances—but little else. “They don’t carry diseases, but they certainly can [cause] bad reactions,” she adds.
Some people have no reaction at all to a bed bug bite. Others have bite marks—red bumps that itch and swell—but they usually don’t appear for days or even two weeks afterwards. (You can’t feel bed bugs bite because they inject an anesthetic.) Sometimes the bites appear in a line.
Try not to scratch. Anti-itch and antiseptic lotions may help. If you have allergic reactions like trouble breathing, get medical help. And, of course, take steps to get rid of the infestation.
Head lice bites
Head lice are much more common in children than adults, largely because kids are—literally—more likely to put their heads together. That makes it easy for the lice to spread from one head to the other.
Head lice cause itchiness, mainly on the scalp, ears and neck, after they lay their eggs, called nits. After the nits hatch, they may look like dandruff flaking off your head.
“Itching on your head is a pretty good sign that you have head lice,” says Kelly. “They don’t carry disease, but they’re a huge nuisance.”
Medicated shampoos—both over-the-counter and prescription—can help get rid of them, as can combing and re-combing your hair carefully and disposing of the critters. If you do get head lice, don’t share anything that goes on your head (including hats, brushes, headphones or hair accessories), and make sure you clean bedding and clothing that could have been infested in hot water.
Read more: 20 Ways to Kill Head Lice
Chiggers are mites that hang out on vegetation waiting for you pass by. Rubbing up against infested plants allows chiggers to attach to your clothes and make their way to your skin, where they start feeding.
“They burrow into the top layer of skin, secrete saliva [that breaks down skin cells], then suck up the dissolved skin cells,” says Kelly.
Chigger bites usually appear in groups together, often on your legs or waist. The bites usually don’t hurt, but they do itch, starting within a couple of hours and getting worse over the next few days. The itch will subside in a few days and the red bumps disappear in one to two weeks.
Scrub the area with soap and water to get rid of any remaining chiggers. Then try calamine lotion or an anti-itch cream like hydrocortisone. Antihistamines can also reduce itching. Like with other bites, try not to scratch, because the bumps can get infected.
Of all the different varieties of ants, fire ant bites may be the most loathsome.
“They’re very aggressive and they bite and sting in a little circle, so it’s a double whammy,” says Kelly.
Not only do ant bites hurt and sting, they also itch. They can also turn red, swell and fill with pus. The best thing to do (once you’ve swiped the ants off you) is wash the bite area with soap and water. Then put ice in a washcloth and apply it 10 minutes on, 10 minutes off. Try antihistamines to quell itching.
As long as you’re not allergic, you’ll be back to normal in a few hours or, if you’re unlucky, a few days. If you are allergic, you may have trouble breathing or feel your throat swell and your heart rate speed up. If that happens, call your doctor or get to an emergency room.