Bug bites are irritating, and some can be harmful. Learn to identify the type of bug bite and when to seek emergency medical care.
Getting a bug bite can be a creepy experience, especially if you don’t know what tiny creature left you with that red, throbbing welt on your skin. Don’t panic. Most bug bites and stings from common insects are harmless and heal quickly. But some bug bites and stings, like those from fire ants, wasps, hornets, and bees, may cause intense pain or even a serious allergic reaction. Others, like poisonous spider bites, require immediate emergency medical care.
Symptoms of bug bites provide clues to the cause and severity. For example, most bug bites cause red bumps with pain, itching, or burning. Some bug bites also feature blisters or welts. Here are some common bug bite clues:
Bedbugs leave a small bite mark on the skin that is red and itchy or in rare cases causes a serious allergic reaction.
Beestings cause a red skin bump with white around it.
Flea bites leave an itchy welt on the skin, often on the ankles and legs.
Mosquitoes leave a raised, itchy pink skin bump or in rare cases a severe allergic reaction.
Spider bites cause minor symptoms like red skin, swelling, and pain at the site or very serious symptoms that need emergency care.
Ticks can carry Lyme disease, and their bite leaves a rash that looks like an expanding bull’s-eye.
Most bug bites are transmitted directly from the insect and occur outdoors. Two exceptions are bedbugs (tiny mites that live in and near beds) and lice, which spread through contact with an infected person, a comb, or clothing.
Certain bug bites can also spread illnesses, such as Zika virus, West Nile virus, Chikungunya virus, Dengue fever, and yellow fever (all transmitted by mosquitoes); Lyme disease (from ticks); Rocky Mountain spotted fever (from dogs or wood ticks); and Chagas disease (from kissing bugs).
In a report posted May 4, 2018, the Centers for Disease Control and Prevention (CDC) cautioned Americans that diseases from mosquito, tick, and flea bites have soared in recent years.
How can you prevent bug bites? Here are some tips from the CDC:
Use an insect repellent that’s been registered with the Environmental Protection Agency (EPA). (The EPA has published an online tool to help you determine which one is appropriate in many varying conditions.)
When traveling, find out what shots or medicines you may need and any precautions you can take.
Wear clothing that covers the skin.
No matter what type of bug bite you have, it is good to know what bit you. Learning to identify a bug bite by how it looks and feels will help you know whether to treat the bug bite at home or seek immediate medical care.
If you have known allergies to bug bites, talk with your physician about emergency care. Some people with severe allergies to bug bites need to have allergy medicine, including epinephrine (such as an EpiPen), with them always.
Mosquito Bites Can Cause a Serious Illness
A mosquito bite appears as an itchy, round red or pink skin bump. It’s usually a harmless bug bite but can sometimes cause a serious illness, such as the Zika virus (particularly harmful in pregnant women), West Nile virus, malaria, or eastern equine encephalitis (EEE). For most people, Zika causes a brief, flulike illness. But newborns of pregnant women infected with Zika have an alarming rate of microcephaly birth defects. Check out the CDC’s Zika Travel Information page to find out more about travel warnings and advisories.
For 2019 (the most recent year for which data is available), a total of 958 cases of the West Nile virus were reported across 47 states in the United States, according to the CDC. Symptoms appear 2 to 14 days after the bite and can include headaches, body aches, fever, vomiting, diarrhea, and a skin rash. People with a more severe West Nile infection may develop meningitis or encephalitis, and have symptoms including neck stiffness, severe headache, disorientation, high fever, and convulsions.
The bite of a parasite-infected mosquito can cause malaria, a rare occurrence in the United States, with only about 2,000 cases diagnosed in the country each year (and the majority of those in people who recently traveled to parts of the world where malaria transmission is more common), according to CDC data. Symptoms are similar to the flu and can include fever, headache, muscle aches, nausea, and vomiting from 10 days to four weeks after the bite. Malaria is serious, but it’s good to know it is preventable and treatable, according to the CDC.
Cases of EEE are rare but deadly. For people infected with EEE, 30 percent do not survive, and many who do develop neurological problems. As of mid-December 2019, 38 cases had been reported for the year in the United States, including 15 individuals who died from the condition, according to the CDC. But the numbers are concerning given that they’ve increased from the usual seven cases reported annually, according to CDC data. Most of the cases have been reported in the Northeast.
Another emerging concern is a species of mosquito just found in Florida, called Aedes scapularis. Previously found mostly in the Caribbean and Latin America, research indicates the mosquito is now well-established in Florida. The invasive species has been found in Broward and Miami-Dade counties, according to a report published in March 2021 in the Journal of Medical Entomology. It’s unclear if the Aedes scapularis mosquitos in Florida are spreading any types of disease, but elsewhere they have been shown to spread some viruses, including the Venezuelan equine encephalitis virus (VEEV) and the one that causes yellow fever.
What Do Bedbug Bites Look Like?
You probably won’t feel pain when a bedbug bites, but you may see three or more clustered red marks, often forming a line. Some people develop a mild or severe allergic reaction to the bug’s saliva between 24 hours and 3 days later. This can result in a raised, red skin bump or welt that’s intensely itchy and inflamed for several days.
If you have hives, get many bites, or notice a bite that looks infected, you should visit a board-certified dermatologist for treatment, according to the American Academy of Dermatology. Bedbug bites can occur anywhere on your body but typically show up on uncovered areas, such as your neck, face, arms, and hands. It’s good to know that although they’re common, bedbugs do not carry disease, according to the CDC.
When to See the Doctor for Spider Bites
Most spider bites are not poisonous and cause only minor symptoms like red skin, swelling, and pain at the site. Other spider bites are a real emergency. If you develop an allergic reaction to a spider bite, with symptoms such as tightness in the chest, breathing problems, swallowing difficulties, or swelling of the face, you need medical care at once. Because spider bites can get infected with tetanus, the CDC also recommends staying on top of your tetanus booster shots and getting one every 10 years.
A bite from a poisonous spider like the black widow or brown recluse is extremely dangerous and can cause a severe reaction. The black widow’s bite, which shows up as two puncture marks, may or may not be painful at first. But 30 to 40 minutes later, you may have pain and swelling in the area. Within eight hours, you may experience muscle pain and rigidity, stomach and back pain, nausea and vomiting, and breathing difficulties. You might not have seen the spider that bit you, but always seek medical attention immediately if there’s a possibility you could have been bitten by a poisonous spider. Call 911 or the American Association of Poison Control Centers at 800-222-1222.
Brown Recluse Spider Bites Need Immediate Medical Attention
The brown recluse spider is poisonous and usually lives in dark and unused spaces. Some people feel a small sting followed immediately by a sharp pain, while others don’t realize they’ve gotten a brown recluse bite until hours later. Four to eight hours afterward, the bite may become more painful and look like a bruise or blister with a blue-purple area around it. Later, the bite becomes crusty and turns dark. It’s also worth noting that this type of spider is found in several Midwestern states, western parts of some Southern states (including Kentucky, Tennessee, and Georgia), and the central Southern states (including Texas, Louisiana, Alabama, Mississippi, Arkansas, and Missouri) — and they’re rarely found outside of these areas, according to the University of Kentucky.
Symptoms of a brown recluse spider bite occur within a few hours and include fever, chills, itching, nausea, and sweating. Because some people will have a serious reaction that can lead to kidney failure, seizure, and coma, it’s important to get medical care at once, according to the National Institutes of Health (NIH) National Library of Medicine. Be sure to seek medical attention immediately if you could have been bitten by a poisonous spider; call 911 or the American Association of Poison Control Centers at 800-222-1222.