Spider Bite Pictures: Appearance and Emergency Signs

If possible, kill and capture the spider (place it in a plastic bag or jar) and take it to your doctor appointment. This way, they’ll know for sure that it was a black widow that bit you.

Black Widow Spider Bite

The black widow is a medium-sized spider — about a half-inch long. Two species are common to the United States:

The southern black widow. This spider has a shiny, black, globe-shaped abdomen. You’ll know it by the red hourglass mark on the underside.
The northern black widow. You’ll notice a row of red spots down the middle of the upper surface of its abdomen. It also has two crosswise bars on the underside. Just to make things interesting, the markings can also be yellow or white. The spider may be brown or have red legs.

These spiders are active at night. They prefer dark corners or crevices, like garages. They only bite when disturbed.

Symptoms

The black widow spider makes a venom that affects your nervous system. Some people are slightly affected by it, but others may have a severe response. Right away, you may feel severe pain, burning, swelling, and redness at the site. You may even see two fang marks.

Other symptoms include:

Muscles that begin to hurt and become stiff, usually within 8 hours
Nausea or vomiting
Difficulty breathing
Severe abdominal pain or cramping
Excessive sweating
Rash and itching
Swollen eyelids
Weakness or tremors. You may not be able to move your legs.

Many of the symptoms of a black widow bite can look like those of other conditions. But if you think you’ve been bitten by this spider, make an appointment to see your doctor.

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IMPORTANT: If you suspect your child was bitten by a black widow, get to the emergency room right away. These bites can be fatal in young children.

In the meantime, try these tips to ease your symptoms and prevent further infection:

Wash the area with soap and water.
Apply a cold washcloth or ice pack wrapped in cloth to the area.
Take an over-the-counter pain reliever, like Tylenol.
If the bite is on your arm or leg, elevate it to prevent swelling.
Apply an antibiotic cream or lotion to the bite.

If possible, kill and capture the spider (place it in a plastic bag or jar) and take it to your doctor appointment. This way, they’ll know for sure that it was a black widow that bit you.

Your doctor will review your symptoms and decide what more treatment, if any, is needed. If they’re severe, you may need muscle relaxants or stronger pain medicine. You may have to stay in the hospital, though that’s rarely the case.

In the most severe cases, your doctor may inject you with antivenin. It’s a drug made from substances in the blood of horses. Antivenin neutralizes the black widow’s venom. That means it prevents it from causing you harm.

Your doctor will only use this treatment after they’ve spoken with another doctor who has experience in treating these bites. Antivenin can cause a number of side effects, so if your doctor gives it to you, they’ll have to monitor you for about 8 to 12 days afterward.

Prevention

Black widow spiders live in cool, dark places like sheds and garages. They normally bite when they’re startled or surprised. To reduce your risk of being bitten, keep storage areas clean. And outside, try to avoid woodpiles, fallen tree branches, and other places they may hide.

Show Sources

Mayo Clinic: “Spider Bites: First Aid.”

KidsHealth.org: “First Aid: Spider Bites.”

Munson Healthcare Cadillac Hospital: “Spider Bites.”

Johns Hopkins Medicine: “Spider Bites.”

Stanford Children’s Health: “Spider Bites in Children.”

Merck & Co.: “Antivenin.”

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.

Disclaimer

Unless you actually see a spider bite you, the only real way to tell if you’ve been bitten is to have it checked by a healthcare professional.

What Does a Spider Bite Look Like?

Spider venom acts differently in humans than bites from a mosquito or flea or a sting from a hornet or bee. Even so, there may be some overlap in symptoms.

The following are some of the “tell-tale” signs and symptoms of a spider bite:

An Expanding Lesion

There are many different things that can cause a lesion to expand or spread. Though an expanding lesion is common in some spider bites (including a brown recluse spider bite), it can also occur with certain skin infections like impetigo .

If you are unsure whether a lesion is growing, draw a line around it and monitor for any changes over the coming hours. Record the time so that you can report back to your healthcare provider if, in fact, the lesion is spreading.

A Bullseye Rash

A bullseye rash—known as erythema migrans —can be a sign of a spider bite. These are characterized by a small area of redness and swelling encircled by a “halo” of reddened skin.

Bullseye rashes are most common in tick bites that cause Lyme disease but can also occur with certain spider bites.

This photo contains content that some people may find graphic or disturbing.

Jake from Atlanta

Fang Marks

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

This photo contains content that some people may find graphic or disturbing.

Tissue Death

Brown recluse spider bites can cause painful, purplish blisters that break open into ulcers. The ulcer forms as a result of the spider’s venom, which is necrotic , meaning that it kills tissues. Necrosis occurs because the venom kills small vessels, called capillaries, that provide blood to surrounding tissues.

This photo contains content that some people may find graphic or disturbing.

Reproduced with permission from © DermNet New Zealand www.dermnetnz.org 2023.

Signs of a Dangerous Spider Bite

Although more than 50 spiders in the United States have venom, their bites are usually not serious and may only cause mild redness, swelling, and pain. Only two spiders in the United States are known to be extremely venomous to humans: the black widow spider and the brown recluse spider.

Brown Recluse Spider Bites

A brown recluse spider is recognized by its dark brown color and violin-shaped body. Its bite may look initially look like a flat area of whiteness (caused by the death of local capillaries and loss of blood flow). It will eventually turn black and blue as blood leaks from the disrupted blood vessels.

Within one to two weeks, the skin may form a purplish or blackish blister. The blister will then erupt and form a painful, open sore (ulcer).

Necrosis can appear either as dry, thick, leathery tissue or as yellow, green, or brownish tissues that are moist, loose, and stringy. When the ulcer heals, it can leave behind an ugly scar.

Other whole-body symptoms of a brown recluse spider bite include:

Headache
Fever
Muscle aches
Joint pain
Nausea
Tiredness

Brown recluse spider bites rarely kill people, but it’s important to get medical attention as soon as you can because a bite can make you very ill.

Black Widow Spider Bites

Black widow spiders are typically black with two reddish triangular markings on the underside of the hourglass-shaped body.

Its bite may look less obvious than a brown recluse spider bite. You may feel a pinprick sensation and see two fang marks accompanied by local redness and swelling.

Black widow venom works quickly, often within an hour, and may cause severe whole-body symptoms like:

Fever with chills
Headache
Nausea or vomiting
Severe muscle cramping
Profuse sweating
Severe chest, back, or abdomen pain

A black widow spider bite is unlikely to kill you but can make you seriously ill and may even require hospitalization.

Wolf Spider Bites

Wolf spiders are recognized by their hairy bodies and multiple eyes (two medium eyes on the top, two large eyes in the middle, and four smaller eyes on the bottom).

Wolf spider bites are usually harmless unless you are allergic to the venom, and most people are not. The bites are about as bad as a bee sting, causing redness and pain that should go away within 24 hours.

Signs That It May Not Be a Spider Bite

If you are bitten by a spider, the chances are that the bite won’t be serious. While this shouldn’t suggest you should wait until symptoms are severe to act, there are ways to reasonably ascertain if a bite is not severe. This is especially true with respect to brown recluse bites.

“NOT RECLUSE” is an acronym for signs and symptoms that a bite is not related to a brown recluse spider. It stands for:

The presence of two or more of these signs almost guarantees that you do not have a brown recluse bite. Some of the same signs may apply to other spider bites.

Numerous Bites

Multiple bites are not typically from spiders, especially not a brown recluse or black widow spider. In cases where there are multiple bites, they could be from insects that travel in groups such as mosquitoes, bedbugs, or chiggers.

This photo contains content that some people may find graphic or disturbing.

T. Critchley

Occurrence of the Bite

Brown recluse and black widow spiders prefer cool, dark places and are more likely to be found in an attic, barn, or wood pile. Many bites also occur when you roll over on a spider in bed or put on shoes or clothes that sat out on the floor overnight.

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.

Timing of the Bite

Most spider bites occur during mating season from late summer into fall. Brown recluse and black widow spiders 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 Centers

With a brown recluse bite, the skin is more likely to be white, purplish, or black rather than red. Though some spider bites can cause a small, red bump, a lesion with a red inflamed center is not suggestive of a venomous spider bite.

In cases like this, a skin infection is a more likely suspect. In fact, a lesion that is swollen, warm to the touch, or red at the center area could very well be due to a staph infection.

This photo contains content that some people may find graphic or disturbing.

Danielle from Binghamton, NY

Elevation of the Lesion

If your bite is a raised bump, it may be from a spider—just not a brown recluse. Brown recluse venom causes lesions that are more often flat or slightly concave due to the destruction of underlying blood vessels and tissues.

Chronic Symptoms

If it takes a really long time for the lesion to heal, it might not be due to a brown recluse bite. Most brown recluse bites heal within three weeks and even the biggest ones heal within three months.

Similarly, symptoms of a black widow spider bite usually take a few days or weeks to resolve.

Large Lesions

Brown recluse bites are known for having dead tissues in the center of the lesion. However, the lesion itself is not going to be bigger than 10 centimeters across (roughly 4-1/2 inches).

Skin Ulceration

Venom from a brown recluse spider can cause blistering and the formation of a single ulcer. But this process is a slow one that takes an average of seven to 14 days. If you have a bite that ulcerates before then, 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 swelling between the neck and ankles, it is not likely to be from a venomous spider.

This photo contains content that some people may find graphic or disturbing.

Exudates

Though some spider bites cause blisters, brown recluse bites are known for being dry in the center. If the lesion is oozing pus, blood, or fluids (referred to as exudates), it’s very unlikely to be a brown recluse spider bite.

A skin ulcer that is oozing or causing local swelling could be from an allergic reaction or a skin infection.

When to Call a Doctor

While not many insect bites will require immediate medical attention, there are some situations where you should always seek care:

If you believe that you’ve been bitten by a venomous insect, like a black widow spider
If you develop a bullseye rash (which could be a sign of Lyme disease)
If a skin lesion continues to get worse over a 24-hour period
If you have symptoms of a severe, whole-body allergy known as anaphylaxis

If these symptoms are not involved, it’s probably fine to keep the lesion clean and watch for any changes.

When to Call 911

Call 911 or rush to your nearest emergency room if you develop the following signs and symptoms after getting a spider bite:

Trouble breathing
Wheezing
Lightheadedness or fainting
Trouble standing

Black widow and brown recluse spider bites can be especially dangerous to children because of their smaller body sizes. If you suspect your child was bitten by one, seek emergency care.

How Spider Bites Are Treated

In most cases, a spider bite can be treated at home. A bite from any spider should be immediately washed with soap and water. To aid with healing, apply an antibiotic ointment three times a day.

If you have pain and swelling you can take an over-the-counter nonsteroidal anti-inflammatory drug (NSAID), such as Advil (ibuprofen). If the bite itches, an antihistamine such as Benadryl (diphenhydramine) can help, especially if it keeps you up at night.

Any bite that worsens or becomes infected should be seen by a healthcare provider.

If your bite is caused by a black widow, your healthcare provider may treat it with muscle relaxants or stronger opioid painkillers. In severe cases, an antivenom can be given, but this is usually a last resort as it may cause anaphylaxis.

If a brown recluse bite grows in size and becomes painful, your healthcare provider may prescribe antibiotics to prevent infection. If it is unclear that you’ve been bitten by a brown recluse, a tetanus shot may be given as a precaution, particularly if you haven’t had one in the past five years.

Summary

Most spider bites are harmless. The exceptions in the United States are bites from the brown recluse spider (which can cause a painful skin ulcer and tissue death) and a black widow spider (which can cause severe, whole-body symptoms). Even so, deaths from a brown recluse and black widow spider bite are rare.

Knowing the signs and symptoms of a venomous spider bite can help you make an informed choice as to whether emergency medical care is needed or not. If in doubt, call or see your healthcare provider.

10 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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Payne KS, Schilli K, Meier K, et al. Extreme pain from brown recluse spider bites: model for cytokine-driven pain.JAMA Dermatol. 2014;150(11):1205-8. doi:10.1001/jamadermatol.2014.605
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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.

Spider Bite Pictures: Appearance and Emergency Signs

Black Widow Spider Bite

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