What Does A Spider Bite Look Like? These Photos Can Help You Identify Different Types

Brown recluse bites are known for having dead tissue in the center of the lesion. However, the necrosis is not going to be bigger than 10 centimeters across (four inches).

Spider Bite Pictures: Appearance and Emergency Signs

Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.

Michael Menna, DO, is board-certified in emergency medicine. He is an attending emergency medicine physician at White Plains Hospital in White Plains, New York and also works at an urgent care center and a telemedicine company that provides care to patients across the country.

Spider bites can sometimes look like other types of skin lesions or bites from insects. Photos of spider bites can help you tell if you were bitten by a spider, but signs, symptoms, and appearance can overlap with other causes.

This article provides photos of different types of skin lesions and discusses whether or not they could be from a spider bite. This, however, can’t help you reach a concrete diagnosis.

Unless you actually catch a spider in the act, the only true way to tell if you were bitten by a spider is to be evaluated by a healthcare professional.

The good news is that though more than 50 spiders in the United States have venom, their bites are not serious and usually only cause redness, swelling, and pain. Only two are venomous to humans: the black widow and the brown recluse.

What Dangerous Spider Bites Look Like

Though it is possible to have a reaction to bites from any type of spider, most of the time, a non-venomous spider bite will not cause major problems. Black widow and brown recluse bites are more serious.

What Does a Brown Recluse Spider Bite Look Like?

A brown recluse spider bite may initially look red. Over time, the bite may develop into a blister. If untreated, it can become ulcerated, which means it will turn into a painful open sore. In some cases, cell death (necrosis) and scarring may occur over a period of time.

What Does a Black Widow Spider Bite Look Like?

A black widow spider bite may look less obvious than a brown recluse bite. You may feel a pinprick sensation when the spider bites you. You may be able to see two fang marks when looking closely at the bite. There may be redness and swelling at the site.

Black widow venom can also cause whole-body symptoms. The venom works quickly, with these symptoms often appearing within an hour of being bitten.

Symptoms of a black widow bite include:

• Muscle cramps or spasms
• Sweating
• Headache
• Severe pain in the chest, back, or abdomen
• Chills, fever, or nausea (with or without vomiting)

If you suspect that you’ve been bitten by a black widow spider, seek medical help right away.

Signs of a Possible Spider Bite

The following are signs that you may have been bitten by a spider.

Expanding Lesions

There are many different things that can cause a lesion that grows, expands, or spreads—including a bite from a spider. Though this type of lesion is common in brown recluse bites, it may also be a sign of another skin infection, such as impetigo.

If you are unsure whether the lesion is growing, draw a line around it. This will help you keep track of whether or not the rash or area of swelling is expanding. Be sure to note the time and date when a line is drawn so you can tell how fast the lesion expands.

Bullseye Rash

A bullseye rash—known as erythema migrans—can be a sign of a bite from a spider.

Bullseye rashes are most common in tick bites that result in Lyme disease, but can also be present with spider bites.

Fang Marks

Depending on the size and type of the spider that bites you, you may be able to see fang marks, or two small, side-by-side holes. Fang marks are sometimes seen with black widow bites.

Necrosis

Brown recluse spider bites can cause blisters that can, in turn, develop into ulcers. The venom in the bite can cause necrosis, or tissue death, around the bite site.

Bullseye rashes, necrosis, expanding lesions, or fang marks at the wound site could be from a spider bite, including venomous ones like the black widows or brown recluse. Get medical attention so you can get a proper diagnosis and treatment.

Signs That It May Not Be a Spider Bite

The first priority is not necessarily ruling out that you were bitten by a spider, but if you were bitten by a venomous spider.

NOT RECLUSE is an acronym for the signs that a wound or lesion is not caused by a brown recluse bite.

The presence of any of these is an indicator that the wound isn’t from a brown recluse. The presence of two or more of these signs almost guarantees that it’s not.

Some of these are also signs that you are not likely dealing with a black widow bite or a bite from any spider altogether, for that matter.

Numerous Bites

In cases where there are multiple bites, they could be from insects that travel in groups, such as mosquitoes, bedbugs, or chiggers.

Multiple bites are not typically from spiders, especially not a brown recluse or black widow.

Occurrence

If you have a rash or bite after working outdoors, it’s possible that poison ivy, another type of insect, or a non-venomous spider could be the cause.

Brown recluse and black widow spiders prefer cool, dark places and are more likely to be found in an attic, barn, or wood pile.

Timing

Most spiders are more numerous from late summer into fall, during mating season. When outdoors in the winter, they go into a dormant state.

Brown recluse and black widow spiders, however, are most active between April and October, when the weather is warmer and drier. Brown recluses are notoriously inactive during the rest of the year.

Red Center

Though some spider bites can cause a small, red bump or redness in the area of the bite, a lesion with a red, inflamed center is not an indicator of a venomous spider bite.

A skin infection is more likely. In fact, a lesion that is swollen, warm to the touch, or red at the center area could be a staph infection.

Elevated

If your bite is a raised bump, it may be from a spider, but not a brown recluse. Brown recluse venom causes lesions that have dark, flat centers.

Chronic

If it takes a really long time for the lesion to heal, it might not be a brown recluse bite. They’ve got a reputation for lasting a while, but most brown recluse bites heal within three weeks, and the biggest of them heal within three months.

Large

Brown recluse bites are known for having dead tissue in the center of the lesion. However, the necrosis is not going to be bigger than 10 centimeters across (four inches).

A lot of infected sores are identified—even diagnosed—as spider bites. In truth, unless you have a spider to identify as the cause, the odds are against a spider bite.

Ulceration

Venom from the brown recluse spider can cause breaks in the skin that worsen and spread. But this process, known as ulceration, is a slow one that can take multiple weeks.

If you have a bite that ulcerates within a week, it’s probably not from a brown recluse.

Swelling

Brown recluse bites typically only cause significant swelling if the bite is on the head or feet. If you have a bite between the neck and ankles that swells, it is not likely to be from a venomous spider.

If you have extreme swelling from a bite on your face, see a doctor prompty.

Any bug bite can lead to swelling from an allergic reaction or envenomation.

Exudes Moisture

Though some spider bites cause blisters, brown recluse bites are known for being dry in the center. If it’s oozing pus or moisture, it’s very unlikely to be a brown recluse bite.

A skin lesion that is ulcerated, oozing moisture, taking a long time to heal, or causing swelling on the hands, feet, or face could be from an allergic reaction or a skin infection that requires treatment.

When to Call a Doctor

Though not all insect or spider bites will require a doctor’s attention right away, there are some situations where you should seek treatment.

Get medical attention if:

• You show signs of an allergic reaction, such as whole-body itching, hives that spread, or swelling of the throat
• You believe that you’ve been bitten by a venomous insect, like a black widow spider
• You develop a bullseye rash (this could be a sign of Lyme disease)

Even if these don’t apply, but your skin lesion grows or continues to get worse over a 24-hour period, you should see the doctor.

If not, it’s probably fine just to keep it clean and watch to see if it changes.

How Spider Bites Are Treated

In most cases, a spider bite can be successfully treated at home. A bite from any spider should be immediately washed with mild soap and water. Apply an antibiotic ointment three times a day. You can also take an over-the-counter nonsteroidal anti-inflammatory drug (NSAID), such as Advil (ibuprofen), if needed. If the bite itches, try taking an antihistamine such as Benadryl (diphenhydramine).

Any bite that worsens over time or becomes infected should be evaluated by a healthcare provider. Black widow and brown recluse bites can be especially dangerous to small children. If you think your child may have been bitten by one of these spiders, seek emergency care at once.

If a black widow bite becomes very painful, your healthcare provider may treat it with muscle relaxants or stronger pain medications such as opioid analgesics. In severe cases, an antivenom can be given. Healthcare providers generally give antivenom as a last resort since it can cause an anaphylactic reaction in some people.

Brown recluse bites may take time to heal. They may also worsen over the first few days before they start to improve.

If a brown recluse bite grows in size and becomes painful, your healthcare provider may prescribe antibiotics. This will help keep the bite from becoming infected. In some cases, your healthcare provider may also recommend a tetanus shot.

Summary

Regardless of what caused your bite, it’s important to monitor the injury and watch for signs of infection or other complications. If you believe you are having an allergic reaction, contact your doctor right away.

A Word From Verywell

If you witness the bite, it can be helpful to capture the insect in a jar or box so that it can be identified—or to try to take a photo. This will help your doctor determine whether or not special treatment may be needed.

Frequently Asked Questions

What are the symptoms of a serious spider bite?

• With a black widow bite, you might feel pain immediately, and then have difficulty breathing, swollen eyes, headache, excess saliva, nausea, cramps, sweating, and rash.
• Brown recluse spider bites don’t hurt immediately but can cause a bull’s eye bruise and blisters with itchiness.

Are wolf spider bites dangerous?

Only if you happen to be allergic to the wolf spider’s venom, and most people are not. Wolf spider bites are typically about as bad as a bee sting, causing redness and pain that should go away in within 24 hours.

When should I get emergency help for a spider bite?

• Trouble breathing or wheezing
• Person has fainted or is too weak to stand

Call a doctor for advice if the bite seems to be spreading or if the person looks very sick or has a fever.

17 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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Additional Reading

• Murphy C, Hong J, Beuhler M. Anaphylaxis with Latrodectus Antivenin Resulting in Cardiac Arrest. J Med Toxicol. 2011;7(4):317-321. doi:10.1007/s13181-011-0183-1
• Vetter R, Swanson D, Weinstein S, White J. Do spiders vector bacteria during bites? The evidence indicates otherwise. Toxicon. 2015;93:171-174. doi:10.1016/j.toxicon.2014.11.229

By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.

What Does A Spider Bite Look Like? These Photos Can Help You Identify Different Types

If you’re scared of spiders, you’re not alone. The eight-legged critters are naturally a little creepy, and the thought of one sinking its fangs into you is something you would probably do anything to avoid. And besides making your skin crawl just thinking about it, getting bitten can be an itchy and semi-painful experience. Not to mention an annoying one, since you’ll have to go through tons of spider bite pictures online to find out exactly what the offender is.

The good news, though, is that out of the 3,000 or so types of spiders in the U.S., only a handful are known to bite, and of those only about three are venomous and poisonous spiders that can put your life at risk, according to research published in “Most spider bites are harmless, as the venom is not toxic to people,” says Paru Chaudhari, MD, a dermatologist at North Peak Dermatology and the co-founder of Quitch bug bite stickers. “There are a limited number of spiders in the world with fangs strong enough to pierce human skin, and they usually do not bite unless they are crushed between you and another object.” Most people who think a spider bit them were usually bitten by a different insect, she adds.

And while definitely unpleasant, spider bites usually heal within about a week (other than brown recluse and hobo spider bites, which can unfortunately take weeks or much longer to mend). “It really depends on the severity of the bite, but if local and minimal, it can take about seven to 10 days to heal,” says Dr. Chaudhari.

Okay, but if you aren’t Spider-Man or a bug enthusiast, how do you know if your bite is a cause for concern? The Instagram photos below (all reviewed by experts) will give you an idea of what different types of spider bites look like, and what you should do if you spot one on your bod.

Meet the experts: Paru Chaudhari, MD, is a dermatologist with over a decade of experience. She is a fellow of the American Academy of Dermatology and a member of the Women’s Dermatologic Society. She is also a co-founder of Mor Ventures Inc, which creates science-backed skin care for families.

Justin Arnold, DO, MPH, is the medical director of Florida Poison Information Center Tampa and an associate professor at the University of South Florida.

Joshua Zeichner, MD, is the director of cosmetic and clinical research and an associate professor of dermatology at Mount Sinai Hospital in New York City.

Rick Vetter, PhD, is a spider expert and staff research associate in the department of entomology at the University of California, Riverside

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First, how can you be sure it’s a spider bite?

Sometimes, spiders leave behind two distinct puncture holes right next to each other. But unless you actually see the spider do the dirty deed, it’s hard to know if it was caused by an arachnid or some other bug.

In fact, the vast majority of “spider bites” are actually bites from other insects like fleas, ticks, and mosquitoes, a rash from an allergic reaction, or skin abscesses from an infection, says Justin Arnold, DO, MPH, an assistant professor at the University of South Florida and the medical director of the Florida Poison Information Center Tampa.

The symptoms are often similar too—pain, swelling, itching, and redness—so it’s an easy mistake to make. In fact, even spider experts and medical professionals have a hard time differentiating bug bites from spider bites just from how they look, Dr. Arnold adds.

“Many people don’t recall an injury or specific bite and hold a common belief that a spider must have bitten them without them knowing,” he says. “In a majority of the cases that we see, a spider was never seen by patient and is not responsible for their infection.”

It’s also important to know what to look for in darker skin tones, says Rajani Katta, MD, a board-certified dermatologist who serves as voluntary clinical faculty of both the Baylor College of Medicine and the McGovern Medical School, University of Texas Houston.

“For myself, and my patients with more deeply pigmented skin, the redness from an insect bite can be more subtle,” she explains. “Instead of a bright red color, I’ll often see more of a faint redness, or a reddish-brown color.”

If she is worried about a more serious spider bite, Dr. Katta will often mark the boundaries of the rash around the bite, and then check those boundaries on a daily basis.