It can be distressing to wake up with a mysterious swollen red rash on your ankle. Could that rash be an insect bite? And what kind of bug bit you? The answers aren't so easy to figure out. Even for experts, it can be challenging to decipher insect bites.
Using your skin's reaction to figure out precisely which insect bit you is challenging, Matt Frye, Ph.D., a community extension educator with the New York State Integrated Pest Management Program at Cornell University, tells TODAY.com.
That's because "human bodies react so differently that it's not (always) possible to look at the results of a bite and determine what caused it," Frye explains.
For example, some people will barely notice a mosquito or ant bite while others break out in itchy or painful welts. If someone has an allergy, an insect bite or sting can mean a severe reaction and even a trip to the emergency department.
But it's important to take a look at your bite to know how to properly treat it, Dr. Amy Kassouf, dermatologist at the Cleveland Clinic, tells TODAY.com.
Doctors and dermatologists pay special attention to a few elements of an insect bite when trying to decipher the cause, she explains, such as bite "patterns and where on the body they were bitten." Clusters of small bites on the ankles could signal chiggers while larger welts on exposed arms and legs might be due to mosquitoes, for instance.
In addition to the rash, experts will want to know what you were doing when you got the bite, other symptoms you have and whether or not you saw the insect that was responsible.
Should you see a doctor for a bug bite?
Thankfully, while some insect bites can be itchy and uncomfortable, Kassouf says that most do not pose a serious risk to humans.
In most cases, the discomfort and itchiness is worst in the first few days of the insect bites. Scratching at them, though, tends to prolong the itchiness. Over time, the itchiness will subside and the bites will heal.
While they heal, you may be able to manage your symptoms with home remedies, like a cool compress, Kassouf says. Or you can try over-the-counter options, like hydrocortisone cream and oral or topical antihistamines.
For bites that aren’t necessarily an emergency but don't seem to be going away quickly enough, Kassouf recommends checking in with your doctor or dermatologist. They can prescribe other treatments, like topical creams or oral medication, to help curb the itch and help the bites to heal, Kassouf says.
There are some serious signs that indicate you should get medical attention for your insect bite quickly, however, Kassouf says.
That includes:
- Symptoms of an allergic reaction, like swelling in the mouth or trouble breathing.
- A widespread rash.
- A rash that is severely painful or itchy.
- Signs of an infection, such as pus or a fever.
Bites from specific types of critters also require medical attention, Kassouf adds, particularly those from venomous spiders and disease-carrying ticks.
Here are some of the mot common bug, insect and spider bites you might be dealing with — and insect bite pictures to help you figure out what type of creature is responsible.
Tick bites
What they look like:
Ticks are so small and hard to see that most people don't notice when a tick bites them.
To make tick bites even harder to identify, "ticks have factors in their saliva that prevent pain, clotting and an immune reaction,” Frye told TODAY.com previously. So, even if you have a tick bite, you may never see or even feel any evidence that it happened, he says.
Some people do develop a small, red, itchy bump that they notice after the tick bite, the Mayo Clinic says. At this early state, the bump may look and feel like a mosquito bite.
If the tick was carrying certain tick-borne illnesses, a tick bite may lead to distinctive rashes that appear in the weeks following the bite. This happens in some cases of Lyme disease or Rocky Mountain spotted fever, for instance.
But not everyone with those illnesses gets the rash. And the rash may not appear on the part of the body where you were bitten, which makes it less obvious and harder to identify.
Other symptoms:
In the weeks following a tick bite, you may start to develop other symptoms.
Some people develop symptoms similar to the flu, such as a fever, headache, chills, fatigue, and muscle and joint pain. Some people also develop a distinctive "bullseye" rash, as described above. If you have symptoms like these, you should see a doctor to get evaluated.
It's particularly important to speak with a doctor if you know develop these symptoms and know you were bitten by a tick or you recently spent time outdoors in tick-heavy areas. You may be eligible to receive prescription prophylactic medications to help manage a tick-borne illness.
Chigger bites
What they look like:
Chiggers, a type of small mite, typically leave clusters of bites that are often very itchy.
In many cases, chigger bites appear as small, red and itchy bumps. Sometimes, they can look like tiny blisters or pimples, TODAY.com explained previously. Chigger bites can also look like welts from hives, and you might develop an inflamed rash around the bites.
Chiggers tend to bite along the clothing line right where your outfit meets your skin. For instance, people often notice chigger bites on areas where skin just peeks out just above socks or along the waistband of leggings. The mites are also known to bite in between the folds of skin where it's warmer.
When diagnosing chigger bites, dermatologists typically notice "little red bumps, typically on the lower legs and ankles,” Dr. Melissa Levoska, an assistant professor of dermatology at the Icahn School of Medicine at Mount Sinai, told TODAY.com previously.
Other symptoms:
At first, chigger bites are painless. But, over the course of a few hours, they become itchy. The itchiness is most severe in the first two days and then subsides over the next week.
But if you scratch at the bites, you can develop a secondary skin infection. That can lead to swelling and pus alongside the itchy bites.
Thankfully, chigger bites don't cause diseases like tick bites can, Levoska says. And most people can manage the itchiness at home, she adds. The bites usually go away within a week or two on their own.
Bedbug bites
What they look like:
Bedbugs often leave bites in a line, a sign that experts sometimes call a “breakfast, lunch and dinner” pattern, Dr. Benjamin N. Ungar, director of the Alopecia Center of Excellence and director of the Rosacea and Seborrheic Dermatitis Clinic at Mount Sinai, told TODAY.com previously.
The parasites, which feed on human blood, are most likely to bite during periods of time when people are immobile. That means they're most likely to bite overnight while we're asleep, when we're sitting still watching a movie on the couch or taking a long train ride.
Most often, bedbugs leave bites on the arms, legs and back — whatever is easiest for them to get to. And they're able to bite any area of skin that isn’t tightly covered by clothing.
What makes bedbug bites so hard to identify is that not everyone develops obvious signs of a bite, the experts say. Some people may not ever notice them because the bedbug bites are small and not itchy. Other people, however, can develop overwhelmingly itchy, raised red welts that look like mosquito bites or hives.
Other symptoms:
Bedbug bites may feel similar to other bug bites, like mosquito bites. That means they might may itchy, swollen and inflamed for a few days. But the itchiness then reduces and the skin heals over time.
Some bedbug bites can be serious, though. People who are allergic to bedbug bites can develop such a strong reaction that they’re in danger of developing anaphylaxis, which can be life-threatening.
Signs of a more severe reaction to bedbug bites include:
- Itchiness in areas that weren't bitten.
- Swelling in the lips or tongue.
- Trouble breathing.
If you have any of these symptoms along with bedbug bites, you should seek medical attention immediately.
Spider bites
There are only a few species of spiders in the U.S. that can bite humans.
“The truth is that most spiders are too small to bite us, including those adorable jumping spiders,” Jody Gangloff-Kaufmann, Ph.D., an urban entomologist and coordinator with the New York State Integrated Pest Management community program at Cornell University, told TODAY.com previously.
But there are a few species that, when they bite, can cause serious symptoms.
Brown recluse spider bites
What they look like:
At first, a brown recluse spider bite may look like a bug bite or bee sting. It can be a small, raised red or purplish bump. You may see a tiny pinprick or two fang marks at the area of the bite.
Over the course of a few hours, the skin may start blistering and the red or purplish color can radiate out from the bite site. From there, the venom can cause skin cell death (necrosis), Levoska told TODAY.com previously.
Brown recluse bites may cause an area of dead skin that's called an eschar, which typically sloughs off and leaves an ulcer behind.
Other symptoms:
Unlike black widow bites, brown recluse bites aren't painful immediately. But the venom from a brown recluse spider can cause serious skin problems around the area of the bite, which typically become increasingly painful in the hours after the bite.
Black widow spider bites
What they look like:
When a black widow spider bites, it typically causes a painful pinprick sensation. The site of the bite then swells slightly and forms a red rash. You might see two fang marks inside the bite area or a mark that looks like a tiny sting.
Other symptoms:
Black widow spider bites are usually painful immediately. It can also cause swelling, redness, pain and numbness or tingling radiating out from the bite, MedlinePlus says.
And, unlike, brown recluse bites, a black widow spider bite can cause symptoms that affect a large area or the entire body.
When black widows bite, they release a neurotoxin into your body which can cause symptoms such as pain throughout the body, nausea and fever. The symptoms typically begin to worsen within 15 minutes of the bite.
Wolf spider bites
What they look like:
Larger spider species, like wolf spiders, can be a little more aggressive and may bite people occasionally, Gangloff-Kaufmann said. But these bites are typically not dangerous because these spiders are not venomous.
These bites look like raised red bumps.
Other symptoms:
Aside from the bump, you may experience some initial pain at the site of the bite, followed by itchiness for a few days.
Mosquito bites
What they look like:
Mosquitoes leave itchy bumps on the skin that may swell and become red. These reactions typically appear within minutes after a bite, the Mayo Clinic says. In some people, the reaction may look like a painful hive or a blister that forms within 24 hours of the bite.
The bites don't tend to appear in clusters but rather as individual bumps, possibly on different parts of uncovered skin. Some people have more severe reactions that cause a hive-like rash in the area around the bites.
Other symptoms:
Mosquito bites don't typically cause symptoms beyond the annoying, itchy bumps. A severe allergic reaction may come with a hive-like rash, swelling and inflammation of the bite area and swelling around the eyes, the Mayo Clinic says.
Bee and wasp stings
What they look like:
"Bees and wasps are stinging you as a defense," Frye says. "You almost instantly know when you've been stung by one of them because they want you to know right away."
Along with the pain, you will likely notice a raised welt pretty immediately, Kassouf says. You might even see a stinger or pinprick mark inside the bump. Some insects, like wasps, will both bite to hold themselves in place and sting you, Frye says.
People who tend to be more reactive may have severe swelling in the entire limb, and "you can get blisters on top because it's so swollen," Kassouf says.
Other symptoms:
Depending on the exact insect that stung you and how reactive you are to the sting, you may have itching, swelling and pain at the site which tends to be worse in the first few days and then gradually go away, Kassouf says.
Ant bites
What they look like:
When ants bite humans, it grabs the skin and also sprays a compound called formic acid, Frye explains. Ant bites tend to be small, swollen bumps that appear in clusters, Kassouf says.
Fire ants also sting humans, Frye says, which can cause small pus-filled bumps on the skin, according to the Cleveland Clinic.
Other symptoms:
Ant bites are typically painful and itchy. In addition to the bites, fire ants use their stinger to inject a venom called solenopsin, which causes a burning sensation, Frye says.
Lice bites
What they look like:
Lice bites are often easier to identify than other critters on this list because you'll likely see the live lice in hair, Frye says. While head lice and body lice are closely related subspecies, pubic lice are a separate species, he explains.
"They're attached to the hair follicle," Kassouf explains. "They will come down to the skin to feed and bite and then go back." At first, you might just have a few. But as they multiply, you may start to notice the small itchy bites on your scalp or other skin areas, she says.
Other symptoms:
In addition to the lice and their bites, you might notice lice eggs called nits, Kassouf says. Nits are tiny, hard and white, and they stick to the hair follicle.
Body lice can also transmit pathogens, Frye says, which is particularly a problem for people who have poor hygiene, such as homeless populations.
Fly bites
What they look like:
It's not that unusual for flies to bite humans because the female flies need to feed on blood to have the energy to produce eggs, Frye explains. And fly bites may look and feel different depending on the particular species of fly that's biting you, he says.
For example, tiny biting midges may cause very small bites with temporary symptoms that last just a few minutes, he explains. On the other end of the spectrum, horse flies and deer flies use "blade-like" mouthparts to slash the skin before eating the spilling blood, which causes large, painful bites, Frye says.
A fly bite typically looks like a red welt, and "it often has a little center core to it," Kassouf says. "It can look a lot like a bad mosquito bite."
Other symptoms:
Again, the other symptoms you might experience depend on the type of fly that bit you.
For instance, if someone is constantly exposed to black flies, for instance, they might experience headaches, fever, swollen lymph nodes and other symptoms of so-called "black fly fever," Frye says.
