How to Tell If You Were Bitten by a Brown Recluse Spider

Nemours Foundation: “Bug Bites and Stings.”

Brown Recluse Spiders: What to Know

It’s rare for someone to stumble upon a brown recluse spider, because these eight-legged creatures are true to their name: They prefer to be left alone. They tend to live in indoor and outdoor spaces where people don’t go most of the time. If you do find yourself in the same place as one, though, it won’t want to attack you — it’ll want to get out of your way. But if it feels trapped, it may bite you.

Brown recluse spiders are one of two spiders found in the United States that can cause real trouble if they bite you. They produce harmful venom that may cause a painful sore at the site of the bite. It may cause even more severe symptoms in some people. If you have a run-in with a brown recluse, it’s wise to have a doctor check you out, just in case.

What Does It Look Like?

A brown recluse might not be brown, but tan. It has a violin-shaped area on the front half of its body, with the neck of the violin pointing toward the spider’s abdomen.

It may be bigger than other spiders that you’re used to seeing. Its body can range in size from a quarter-inch to three-quarters of an inch, and its long legs make it appear even larger.

Most spiders have eight eyes, but a brown recluse spider has six. Two are in the front, and there are two more on each side of its head.

Brown recluses are found mostly in the Midwest or the South. The spider favors indoor spaces, like attics, garages or dark closets. Outdoors, it hides in out-of-the-way places — under logs, beneath porches, or within piles of rocks.

Symptoms of a Brown Recluse Bite

A bite might not hurt at first or even leave a mark. For some people, it feels like a pinch or a bee sting.

Within the first day or two after you’ve been bitten, you may notice:

• Pain or redness at the site of the bite
• A deep sore (ulcer) that forms where you were bitten, with the skin at the center turning purple
• Fever
• Chills
• Nausea
• Joint pain
• Feeling weak
• Seizures or coma (very rare)

Diagnosis

Your doctor will want to be as certain as they can that you were, in fact, bitten by a spider. It’ll help if you can describe what the spider looked like. Some people try to catch the bug to show the doctor. That’s fine, as long as you can do it safely. You might just try to take a photo of it.

Treatment

If you suspect your small child was bitten by a brown recluse, see your doctor right away. Their bodies can’t ward off the dangerous effects of the spider’s venom.

For adults, most brown recluse spider bites can be treated at home with good results. But about 10% of them cause ulcers or blisters that damage your skin so badly that you need a doctor’s care.

If your symptoms are mild, try these simple home remedies:

• Clean it with soap and water.
• Apply antibiotic cream.
• If you were bitten on an arm or leg, keep it raised while you’re resting. This can reduce swelling.
• Put ice on it.
• Take over-the-counter pain medicine.
• Watch for more severe symptoms.

See a doctor right away if you notice any of these symptoms:

• The bite has formed an ulcer or blister with a dark (blue, purple or black) center.
• You’re in extreme pain.
• You have an infection at the site of the bite.
• You’re having trouble breathing.

Some spider bites can have tetanus spores, so you might need a tetanus shot after you’ve been bitten. If you have an infection, you may need antibiotics.

Show Sources

U.S. Department of Labor: “Brown Recluse Spider.”

CDC: “Venomous Spiders,” “Types of Venomous Spiders.”

Mayo Clinic: “Spider Bites Overview,” “Spider Bites Diagnosis,” “Spider Bites Symptoms and Causes,” Spider Bites: Preparing for Your Appointment,” “Spider Bites Treatment.”

Nemours Foundation: “Bug Bites and Stings.”

University of California: “Brown Recluse and Other Recluse Spiders.”

How to Tell If You Were Bitten by a Brown Recluse Spider

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

Chris Vincent, MD, is a licensed physician, surgeon, and board-certified doctor of family medicine.

Table of Contents
Table of Contents

The brown recluse spider ( Loxosceles reclusa) is one of the most poisonous spiders in the United States. Their venom is necrotic, meaning that it destroys blood vessels, causing tissue near the site of the bite to die.

Getting bitten by one is uncommon and the bite alone rarely kills people. That said, severe reactions to a brown recluse spider bite can occur. If the reaction goes untreated, life-threatening complications may arise.

This article details the signs and symptoms of a brown recluse bite and who’s at risk of being bitten. It also covers what you should do if you think you have been bitten by one of these spiders.

Where Are Brown Recluse Spiders Found?

Brown recluse spiders live in very specific parts of the south-central United States. The spiders are called “recluses” because they are hard to find even in the places where they live.

States With Brown Recluses

• Alabama
• Arkansas
• Georgia
• Illinois
• Indiana
• Iowa
• Kansas
• Kentucky
• Louisiana
• Mississippi
• Missouri
• Nebraska
• Ohio
• Oklahoma
• Tennessee
• Texas

Rare, isolated instances of brown recluses (such as by being brought into the state) have occurred in:

• Arizona
• California
• District of Columbia
• Florida
• North Carolina
• New Jersey
• Pennsylvania
• Washington
• Wyoming

In many cases, it’s thought that the spiders arrive in boxes and shipments that come from the states where they are native.

Brown recluses like dark, dingy places where they can hide under things. They are known to build their nests in attics, storage rooms, inside furniture and closets, and in other dry, dark, and warm spaces in homes and buildings. You may also find them under a woodpile outside.

Within their habitat, there can be serious infestations—if there is one brown recluse spider, there are most likely dozens or even hundreds more of them. However, even in homes with serious brown recluse infestations, it is unusual for people to get bitten.

They are nocturnal, so they are awake at night, and are more likely to run from you than strike. They will only bite out of self-defense.

Brown recluse spider bites are most likely to occur when the spider gets trapped against your skin. In many cases, the spider has crawled into a clothing item or a shoe and bites when you put the item on.

Identifying a Brown Recluse Spider

The only way to be sure that a bite came from a brown recluse spider is to see the spider bite you, capture it, and then definitively identify its type.

Most don’t even get the chance. Many people don’t even realize they’ve been bitten at first. It’s even rarer for a person to see the spider bite them and be able to catch it before it scurries off.

If you’re lucky enough to see the spider, here’s how to check for these telltale traits.

Look at the Legs

Brown recluses have legs that look different from other spiders. If you look at brown recluses from the side, you’ll see how the body sits low and the legs angle up to a point.

The angular, slanted leg shape gives brown recluses their scientific name (Loxosceles means “slanted legs”).

If a spider does not have this type of leg, it’s not a brown recluse. If it does, you can also check for other characteristics of brown recluses.

There are also two other features that set brown recluses apart from other species of spiders:

• No spines: Unlike many other spider species, Loxosceles do not have spikes or spines on their legs. The legs of brown recuses are smooth.
• Solid color: Some spiders have multicolored legs, but Loxosceles’ legs are solid. Brown recluses have no stripes and no patterns.

Check for Three Groups of Two Eyes

Another key feature to look for to identify brown recluses is the eyes. Brown recluse spiders have six eyes. The eyes are paired in groups of two ( dyads ). One dyad will be up front and the other two will be on either side of the head.

Other spider species might have eight eyes, or six eyes arranged in two triads (groups of three).

You cannot be sure a spider is a brown recluse based only on what the eyes look like. However, if the eyes are not in the proper pattern, then it’s definitely not a brown recluse.

Inspect the Body

Brown recluses also have specific features on their bodies that make them look different from other kinds of spiders.

• The body of a brown recluse (without legs) will be no more than 3/8 of an inch long. Including the legs, the average brown recluse is around the size of a quarter.
• The big round part on the backside of a brown recluse (abdomen) is a little fuzzy, has very fine hair, and is a solid color.

Find the Fiddle Marking

Brown recluses often have a violin-shaped mark on their back. However, not all brown recluses have it and even if it’s there, you might not be able to clearly see it.

There are also other spiders that also have the violin marking on their backs that are not brown recluses.

All of that said, identifying a brown recluse is difficult even for spider experts and doctors. Whether you think you’ve been bitten by a brown recluse or you’re unsure, seek medical attention if you notice a bite getting worse.

Brown Recluse Bite Symptoms

In 2014, only 1,330 brown recluse spider bites were recorded in the United States. Of these, 481 people required medical care.

Most brown recluse bites either don’t have any symptoms at all or there is a little swelling with a red bump. Some bites will develop a boil or a pimple that resembles an ingrown hair.

The bump might also be mistaken for a skin infection due to Staphylococcus or Streptococcus . At the same time, these bacteria can infect the spider bite wound.

When symptoms become severe enough to require medical care, it’s because the bite has become infected or caused what’s known as loxoscelism .

Signs of Infection

As is the case with any wound, a brown recluse spider bite can get infected if bacteria makes its way into the wound.

It’s always important to be on the lookout for signs of infection when you have a bite or wound of any kind.

Initial signs of infection include:

• Increased pain
• Swelling
• Warmth
• Redness in or around the bite

Loxoscelism

Necrotic arachnidism is a condition that can potentially occur when a person is bit by a spider that has venom that causes tissue to die.

When that spider is a brown recluse spider, the condition is referred to as loxoscelism. This is because the brown recluse belongs to a genus of spiders known as Loxosceles.

Loxoscelism only occurs in a minority of brown recluse spider bites. When it does, the effects are most often limited to the skin around the bite (local).

Local symptoms of loxoscelism due to a brown recluse spider bite include:

• Reddened skin around the bite
• A blister that forms at the bite site
• Mild to intense pain and itching for two to eight hours after the bite
• An open sore (ulcer) and tissue death that develops a week or more after the bite. The sore may take months to heal.

Complications

Untreated infection can lead to serious and possibly life-threatening complications, particularly:

• Cellulitis: A skin infection that has spread from the top layer of the skin into deeper layers
• Sepsis: Your body’s extreme response to infection in which chemicals in the blood trigger widespread inflammation throughout the body

Untreated sepsis can progress to septic shock, causing your blood pressure to drop dangerously low and your organs to start to shut down.

In the most severe cases of systemic loxoscelism, a person may develop:

• Hemolytic anemia: Red blood cells are destroyed faster than they can be made in your bone marrow, resulting in reduced oxygen delivery throughout the body and potential organ damage
• Thrombocytopenia : Low levels of platelets, blood cells that help form blood clots, which puts you at risk for excessive bleeding
• Kidney failure: The kidneys are injured by toxins in the venom, leading them to shut down and no longer be able to filter toxins and waste products from your blood

Systemic loxoscelism is a medical emergency. It’s rare, but if it is not treated, it can lead to death. Fortunately, very few deaths due to loxoscelism have been reported.

A 2017 study looked at loxoscelism cases ranging from 1995 through 2005. Of the 57 reported cases of moderate to severe loxoscelism, only two resulted in death. Both individuals—an older man and a young girl—were healthy prior to the bite.

It should also be noted that the study found 373 possible cases of loxoscelism over that 20-year period. The majority only led to minor symptoms that cleared up within a few weeks.

When to See a Healthcare Provider

It’s normal for any bug bite to leave a little redness and swelling around the bite site. It’s also normal for there to be some pain and itching.

If those are your only symptoms and they don’t get worse, you don’t need to see your healthcare provider. You should still watch the wound closely to make sure nothing changes in the hours or days after you are bitten, though.

Consult with a healthcare provider if the wound worsens or any of the following apply:

• The spider bite is on your face
• Your pain increases or is severe
• Redness spreads out from the wound
• Red or dark streaks extend from the wound
• A sore, boil, or ulcer forms at the bite site
• Pus or cloudy drainage oozes from the wound

In the case of a boil or ulcer, a healthcare provider may take a swab sample and culture it to test for bacteria. This will help them determine whether the wound is a spider bite or not.

Seeking Emergency Care

Any kind of systemic (body-wide) symptoms following a brown recluse bite should be treated as a medical emergency. This may indicate a progressing infection or loxoscelism.

Call 911 or go to the nearest emergency room if you develop any of the following:

• Fever or chills
• Widespread skin rash with many tiny, flat purple and red spots
• Nausea and vomiting
• Joint pain
• Trouble breathing
• Rapid heart rate
• Confusion
• Any other worrisome symptoms

In some cases, what a person thinks is a spider bite is actually another type of necrotic skin infection, such as necrotizing fasciitis. Skin infections like this can be much more dangerous than a spider bite.

Don’t hesitate to get medical care if you suspect infection or loxoscelism. Both conditions can rapidly get worse unless treated promptly.

Treatment

Most brown recluse bites heal just fine without any medical intervention. The first thing you should do for a new bug bite is wash it with mild soap and water.

From there, you can apply simple first aid to ease pain and swelling. The RICE method is recommended.

• Rest
• Ice
• Compression
• Elevation

Start by icing the bite area, taking care not to apply the ice directly to your skin. If possible, wrap the area with a compression bandage and then elevate it above the level of your heart.

Any time you place a bandage over a wound, make sure to remove it at least once per day to check for signs of developing infection. After removing the bandage, clean the wound with soap and water again, pat it dry, then re-dress it.

Over-the-Counter Medication

An over-the-counter anti-inflammatory medication, such as Advil (ibuprofen) or Aleve (naproxen) can also help reduce pain and swelling.

If you notice that the skin around the bite starts to look a bit red and swollen, wash the area with soap and water, pat it dry, then apply an over-the-counter antibiotic ointment. Keep a close eye on the wound for any increasing signs of infection.

Do not continue to self-treat your spider bite wound if it becomes infected or if a boil or ulcer develops. You will need more specialized treatment by a healthcare provider.

For Infection

You may be given a course of oral antibiotics if you have a mild case of cellulitis. If it’s severe, you will be given intravenous (IV) antibiotics in the hospital.

Should the infection progress to sepsis, you will need to be treated aggressively. You will need antibiotics right away and IV fluids to prevent dehydration.

If your blood pressure drops, you will be given a vasopressor medication, which constricts your blood vessels to raise blood pressure.

You will also be given supportive care based on your symptoms. That could once again include oxygen or a breathing machine. If your kidneys are affected, it could include dialysis.

In some cases, surgery may be needed to remove dead tissues or amputate a limb. This is a last resort (and an extremely rare one at that), but it will ensure the entire infection is gone.

For Loxoscelism

Treatment for local loxoscelism symptoms involves wound care and pain management. The healthcare provider will clean the wound and recommend that you use the RICE technique.

For pain relief, you may be given a nonsteroidal anti-inflammatory medication (NSAID) such as ibuprofen or naproxen. Very severe pain may be treated with an opioid, such as morphine.

You will be admitted to the hospital if you have signs of systemic loxoscelism. You will likely be given antibiotics and pain relievers.

You will then be given supportive care, which focuses on reducing your symptoms. For example, if your breathing is affected, you will be given oxygen therapy. If you develop hemolytic anemia, you may be given a blood transfusion.

The risk of life-threatening complications due to a brown recluse spider bite is very small, as are your chances of needing life-saving treatments for it. Nonetheless, you should monitor your spider bite closely to ensure that dangerous symptoms don’t have a chance to develop.

If you happen to know what bit you, let your healthcare provider know. There are no specific antidotes for brown recluse spider venom. But informing your provider will keep them more alert for specific loxoscelism symptoms, and help them to prepare treatment options in case symptoms develop.

Prevention

While you can’t always prevent a spider bite, you can take steps to lower your chances of being bitten.

Take note that brown recluse spiders are insect hunters. This means that they will seek out spaces where they can easily find crickets, cockroaches, and other bugs to eat.

If you live in a state where brown recluse spiders are found, you will want to protect your spaces from bugs that brown recluses feed on. Steps you can take include:

• Make sure that all your windows and doors are well-sealed.
• Keep your home clean and tidy.
• Keep your food sealed, limit where you eat, and don’t leave food lying around.
• Consider reaching out to a pest-control specialist if you can’t get rid of bugs on your own.

Keep in mind that brown recluses are most likely to bite if they feel trapped or provoked. Always shake out your clothing, blankets, and shoes before you use them.

Summary

If you’re in the south-central United States where brown recluse spiders live, you should be aware of what the spiders look like and where they prefer to nest.

If you get bitten and are able to trap the spider, bring it with you to see your healthcare provider. Clean the bite area with soap and water and watch it closely for changes. See a doctor if a boil or ulcers develop or if the wound gets hot, hard, or looks worse.

In rare instances, you may be at risk for loxoscelism, in which the skin around the bite begins to die away. Getting a diagnosis as soon as possible can ensure you have the right treatment to stop a potentially life-threatening problem.

Frequently Asked Questions

Where do brown recluse spiders live?

Brown recluse spiders live in the south-central United States. They prefer dark, enclosed spaces, such as attics, basements, cupboards, boxes, under rocks, and in the bark of dead trees.

What are the symptoms of a brown recluse spider bite?

Symptoms of a brown recluse spider bite include a rash, fever, nausea or vomiting, headache or body aches, and a black ulcer or blister at the bite location. Several hours or even days after the bite, the affected area can develop burning, itching, pain, and redness.

How do I treat a brown recluse spider bite?

• Wash the affected area with soap and water
• Wrap an ice pack in a towel and apply it to the area
• Apply an antibiotic lotion or cream to prevent infection.
• If the bite is on an arm or leg, use the RICE treatment (rest, ice, compression, elevation)

If the bite develops into a boil or ulcer, see a doctor right away.

Should I worry about a brown recluse spider bite?

Brown recluse spiders are one of the few species of spider that pose a potential threat to humans.

There are more than 3,500 known species of spider in the United States. Although spiders cause fear in many people, only about five main groups worldwide can potentially cause significant reactions in humans.

In the U. S., these venomous species fall into two different groups: Brown spiders and widow spiders.

Brown recluse spiders belong to the brown spider group. The other well-known venomous spider is the black widow spider, which falls into the widow group.

The brown recluse spider is also known as the violin or fiddle-back spider. It lives in midwestern and southeastern parts of the U.S. This spider is brown and has a darker, violin-shaped spot on its back.

Unlike other spiders, which typically have eight eyes, brown recluse spiders only have six, arranged in three pairs of two eyes each. The legs of a brown recluse are long, thin, and covered in small hairs. The scientific name for this spider is Loxosceles reclusa, which can be translated from Greek as “with slanted legs.”

These spiders are most active at night and rest during the day, hidden away in dark areas. If they come indoors, brown recluse spiders prefer closets, attics, basements, and other dark areas of the house. They seem to prefer dry areas.

The venom of a brown recluse can be highly toxic, but the spiders are only able to release a small amount during a bite. People are also more likely to come into contact with the male spider, which has only half as much venom per bite as a female spider.

Why do they bite humans?

Brown recluse spiders only rarely bite humans and do so out of self-defense. They are not aggressive towards humans and prefer running away to biting.

Bites occur when the spider gets trapped against the skin, such as in tangled bedsheets or in clothing and shoes.

It is important to check and shake out linen and clothes before using them when living in an area to which these spiders are common, especially if they have not been in recent use.

There are many myths about brown recluse spider bites.

One common myth is that their bite always causes severe wounds and destroys skin tissue. In reality, only a small number of bites result in this type of injury. Most bites either cause no symptoms at all or only mild reactions.

Extremely rare complications can occur across the entire body , including acute anemia, blood clotting problems, and kidney failure.

The bite is usually painless to begin with, and occasionally symptoms will progress with time. Most bites occur on the thigh, upper arm, and chest.

If a skin reaction is to occur, over the first hour a person may experience the following symptoms around the area of the bite:

• redness
• swelling
• a burning sensation

Over the next 2 to 6 hours, the site of the bite gets bigger, becomes more painful and forms a blister. if the area around the bite becomes more purple in color around 12 to 24 hours after the bite, skin death will likely occur. This is known as necrosis. If necrosis occurs, it can take several weeks or even months for the wound to heal fully.

However, according to spider experts at the University of Florida, if there are no signs of skin changes within 48 to 96 hours, the wound will not become necrotic and should heal properly.

While these spiders do not often bite humans, they pose a slightly higher risk to people who work indoors.

Machinists, janitors, and housekeepers might face an even higher risk, due to working in areas where there is an increased likelihood of coming into contact with the spiders.

Living in the Midwest or the southeastern U.S. is the main risk for accidental encounters with this type of spider.

Complications

Despite their fearsome reputation, only about 10 percent of brown recluse spider bites lead to serious skin complications.

There are no documented cases of death as a result of a brown recluse spider bite.

What people call spider bites are often misdiagnosed, usually the result of other skin conditions or infections.

Tick bites, viral, fungal and bacterial infections, drug reactions, and skin complications from diabetes are common causes of similar-looking skin reactions.

Share on Pinterest Clean a brown recluse spider bite with water and mild soap as soon as it happens.

People can typically treat real spider bites at home. If possible, people should collect and identify the spider responsible.

Do this by trapping the spider under a clear cup or jar so the spider can be easily seen, and slowly sliding a piece paper under the container. Turn the container over and secure the paper over the top or attach a lid.

If someone receives a bite, they should clean the wound with mild soap and water.

If the bite is causing discomfort, elevate it if possible and apply a cool compress or a covered ice pack to reduce swelling and pain.

A pain reliever, such as acetaminophen or ibuprofen, can be helpful in reducing discomfort. An antihistamine, such as Benadryl, may also help with any itching.

People should see a doctor for any wound that is painful, red, oozing, or not healing properly.

If a brown recluse spider is confirmed as the cause, the doctor may recommend a tetanus booster if a person has not received one in the last 5 years. The doctor may also want to check the wound in 2 to 3 days after the bite, to ensure that the venom is not destroying tissue. Treatment can commence quickly if there are any concerns. This reduces the risk of further complications.

Diagnosis

There are many other conditions that can cause a severe wound similar to brown recluse spider bites. These conditions include tick bites, infections from bacteria, viruses and fungi, diabetes, and other skin conditions.

Unless a person lives in an area where brown recluse spiders are known to live and has caught the spider for proper identification, the cause of a wound should not be blamed on a brown recluse spider bite.

A person with a brown recluse spider bite has an excellent chance of recovery, especially with proper care, since most bites require no particular treatment and heal on their own.

In most cases, minor wounds from these types of bites heal completely within a week or so.

People with other medical conditions, such as diabetes or immune system problems, are at a higher risk of complications. These individuals are also at higher risk for a wide variety of skin infections and other skin problems. However, it is especially important for them to contact their doctor in the event of an actual or suspected brown recluse spider bite within 24 hours if there is a reaction. Any wound that is not healing properly needs to be evaluated, regardless of the cause.

Though brown recluse spider bites are rare, it is possible to reduce the risk of getting one. These steps are important for people living in the areas where brown recluse spiders settle.

Share on Pinterest Outdoor wood piles can attract brown recluse spiders.

The best way to do this is by avoiding areas where brown recluse spiders tend to live, such as dry areas with outdoor wood or rock piles. Someone who works near or in these areas should wear gloves.

When indoors, people should be sure to shake out clothing, shoes or bedding that they have not used for a while, particularly if they are kept in an attic, basement, or dark closet.

Taking other measures to prevent brown recluse spiders from setting up home can be useful. Cleaning out attics, sheds, closets, and basements gets rid of the spiders’ preferred hiding places. However, it’s important to remember, a brown recluse spider would rather escape from you than bite you.

Removing outdoor woodpiles can prevent their accumulation in these areas.

Even though these spiders have gotten a bad name, the actual risk of significant injury from a brown recluse is quite small.

Simple preventive measures can be highly effective, further reducing any risk of encountering these spiders.

Q:

What should I do directly after a brown recluse spider bite?

A:

Since most brown recluse spider bites result in either no symptoms or only a mild reaction, washing the bite with warm soapy water and patting it dry with a clean cloth is the first step.

Any reaction within a week of the bite that includes fever, chills, rash, yellowing of the skin, paleness, fatigue, dizziness, or vomiting requires immediate medical attention.

If a skin reaction is going to occur, changes should be seen within a few hours. This includes increased size, redness, pain, and usually blisters. Within a day the wound may become purple. This is often a sign that skin death, or necrosis, will occur.

It is important to see your doctor if these types of skin changes happen so that you can receive any appropriate vaccinations, medications, or wound care. You will likely need close follow-up to make sure the wound heals properly.

Judith Marcin, MD Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Last medically reviewed on August 29, 2018

• Bites and Stings
• Dermatology
• Immune System / Vaccines
• First Aid