How To Tell If A Spider Is A Brown Recluse?

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.

Michael Menna, DO, is a board-certified, active attending emergency medicine physician at White Plains Hospital in White Plains, New York.

  • Bites & Stings
  • Allergies & Anaphylaxis
  • Breathing Emergencies
  • Broken Bones
  • Bruises, Cuts & Punctures
  • Heat & Cold Exposure
  • Infections
  • Rash
  • Emergency Preparedness
  • Calling for Help

View All

The brown recluse spider is known to have a seriously venomous bite. Though the bite is extremely rare, it is responsible for a condition called loxoscelism . This is the only known cause of necrotic arachnidism (tissue death from a spider) and derives its name from the Loxosceles genus to which all recluse spiders belong.  

But how do you know if it really was a brown recluse that bit you? This is a very common question because there is a lot of anxiety and fear surrounding the brown recluse. Capturing the spider responsible will certainly help you identify it, just try not to put yourself in danger of another bite to do so.

Many of your fears can be put to rest with a little understanding of the brown recluse. For instance, these spiders only live in certain parts of the United States and death from a bite is very rare. Also, keep in mind that not all skin boils and necrotic (dead) tissues are caused by brown recluse bites or even spider bites, for that matter.

Do You Live Where Brown Recluses Do?

Recluse spiders are called recluse because they do not like to be seen. These nocturnal creatures will not attack people unless they’re provoked. The majority of brown recluse bites occur because the spider ended up in the person’s clothing.

With that knowledge, where you live is actually the first clue on whether or not you’ve been bitten by a brown recluse. This particular species is found only in the South-Central United States.  

In one study, researchers from the Department of Entomology at the University of California, Riverside invited people to send them spider specimens they believed to be brown recluses. Out of a total of 1,773 arachnids submitted from 49 states, 158 different species were identified. From those 29 states where brown recluses are not common, only 2 brown recluse specimens were identified.  

This study found that if you get bitten outside of where brown recluse spiders are known to live, the chances that it came from a brown recluse are nearly zero. It is more likely that the injury was caused by any number of other things, possibly even another species of spider that is less venomous.

For instance, if you were bitten in northern California or Maine, there’s almost no chance it’s from a brown recluse unless you recently returned from Mississippi.

You can rule out the brown recluse if you aren’t in the areas where brown recluses are known to live.

Was It a Brown Recluse?

Assuming you’re in the territory of the brown recluse, it is best if you were able to see the spider that bit you. However, many people do not even realize when they are bitten, so sightings are rare.

If you were, by chance, able to capture the spider that bit you, that is even better. Classifying it is difficult and only an arachnologist (spider expert) can accurately identify a brown recluse for you. It’s probably beyond the expertise of your doctor as well, though you should see him anyway if the bite worsens.

While you and your doctor may not be able to identify the brown recluse, there are a few indicators that you have a spider that is at least in the recluse family. If you can safely observe it, here’s what to look for:

  • A recluse will have six eyes set in three pairs called dyads. One dyad will be up front and the others on either side of the head. Most spiders have eight eyes.
  • The furry abdomen (the larger section) will have fine hairs and be a solid color.
  • The legs are one solid, light color and have no spines.
  • The body (without the legs) is not more than 3/8-inch long.
See also:  How To Find A Spider In Your House?

Brown recluses are also called violin spiders or fiddlebacks. These names refer to a violin-shaped mark on the spider’s back. However, it’s not always obvious on brown recluses and it shows up on other species as well. Look for the other identifying information instead of relying on the violin.

The problem is that it’s more than likely you didn’t even feel the bite. In most cases of loxoscelism, the bite is identified by symptoms several hours or days after the fact.  

Symptoms of a Brown Recluse Bite

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. These may be completely indistinguishable from an ingrown hair or a skin infection like staphylococcus or streptococcus.

One extensive review of spider bites notes that tissue death around the bite location can spread within a few days. You might notice skin that is red near the center or boil, turning white, then blue as it spreads.  

Some of the worst brown recluse bites can lead to necrotic arachnidism , which looks like an open wound that doctors often call ulcers. The term necrotic arachnidism literally means tissue death by means of a spider bite.  

Skin infections can lead to necrotic ulcers which look similar to those caused by brown recluse bites. The difference is that necrotic skin infections can be much more dangerous and treatment with antibiotics is possible, so it’s very important you see a doctor.

On the other hand, antibiotics do not work for brown recluse bites and there are very few confirmed deaths from loxoscelism. A study published in 2017 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 resulted in only minor symptoms that cleared up within a few weeks.

Treatment for a Brown Recluse Bite

Most brown recluse bites heal just fine without any medical intervention or first aid. If you see it happen or suspect that you were bitten, the recommended treatment is to use the common first aid technique called RICE (Rest, Ice, Compression, and Elevation). Wrap the area of the bite with a compression bandage, use ice on it, and elevate it.

If the bite develops into a boil or an ulcer, see a doctor. This typically is not an emergency situation, but you should have a physician take a look. The doctor might take a swab from the boil and culture it to test for bacteria. This helps him know if it can be treated with antibiotics and aids in determining the real cause, spider bite or not.  

If you didn’t see and feel the spider bite you, then there’s really no way to know if it’s a brown recluse bite. In that case, it’s important to see a doctor for any boil or red, raised area that gets worse, especially if it feels hot and hard.

A Word From Verywell

Though you may be tempted to worry, rest assured that brown recluse bites are very rare. Follow the recommendation of RICE for first aid and monitor the area you think is a bite. If you notice anything unusual or boils appear, see your doctor. With a little diligence, you will be fine.

Entomology at the University of Kentucky. Brown Recluse Spider. Updated July 12, 2018.

Rahmani F, Banan Khojasteh SM, Ebrahimi Bakhtavar H, Rahmani F, Shahsavari Nia K, Faridaalaee G. Poisonous Spiders: Bites, Symptoms, and Treatment; an Educational Review. Emerg (Tehran). 2014;2(2):54-58.

Pezzi M, Giglio AM, Scozzafava A, Filippelli O, Serafino G, Verre M. Spider Bite: A Rare Case of Acute Necrotic Arachnidism with Rapid and Fatal Evolution. Case Rep Emerg Med. 2016;2016:7640789. doi:10.1155/2016/7640789

Robinson JR, Kennedy VE, Doss Y, Bastarache L, Denny J, Warner JL. Defining the complex phenotype of severe systemic loxoscelism using a large electronic health record cohort. PLoS One. 2017;12(4):e0174941. doi:10.1371/journal.pone.0174941

American Osteopathic College of Dermatology. Spider Bites.

Tell-Tale Signs It’s Not a Brown Recluse Spider

It takes an expert to identify one, but almost anyone can say it’s not

  • facebook
  • twitter
  • linkedin

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 a board-certified, active attending emergency medicine physician at White Plains Hospital in White Plains, New York.

  • Allergies & Anaphylaxis
  • Bites & Stings
  • Breathing Emergencies
  • Broken Bones
  • Bruises, Cuts & Punctures
  • Heat & Cold Exposure
  • Infections
  • Rash
  • Emergency Preparedness
  • Calling for Help

View All

To identify a brown recluse spider you need a very strong microscope and a spider expert.

See also:  What Happens When You Get Bite By A Spider?

And an actual brown recluse, which might be harder to find than you think.

These guys are tough to identify even by the experts. Unless you actually have a specimen to analyze, there’s no way to know what it was that bit you or that scurried across the kitchen floor. It takes a close examination of the spider itself to rule out all the other potential species that look like a brown recluse but don’t pack nearly the same punch.

Likewise, you can’t tell a brown recluse bite by the wound. There’s no blood test or culture that can show the presence of brown recluse venom in a suspected spider bite.

There’s no classically reliable pattern of signs or symptoms to help pinpoint this particular species.

Just Because It’s Brown Doesn’t Mean It’s a Recluse

Ladyb695 / Wikimedia Commons / CC BY-SA 3.0

If anything, identifying a brown recluse is more about ruling out what it isn’t rather than figuring out what it is. Using these steps can help you figure out when it’s not a brown recluse. First, start with where you found the spider.

Did You Find Your Spider in Known Brown Recluse Territory?

Brown recluse spiders live in a well-defined area in the south-central part of the United States.   Within their habitat, they’re hard to find. They are called «recluse» for a reason: They don’t like to play with others. These spiders like dark, dingy places. They hide under things and prefer living where the sun don’t shine.

Inside their habitat, brown recluse spiders cause serious infestations. Where there is one, there are most likely dozens or even hundreds. However, even in homes with such outrageous infestations, bites are very rare.

The scientific name for the brown recluse is loxosceles reclusa. In all those other colored areas of the map are other loxosceles species (Texan recluse, desert recluse, etc). They’re related to the brown recluse and all have similar venom. Indeed, some of the other loxesceles species have worse venom than the brown recluse.

So, if the spider was found outside of the known habitat of a brown recluse, then it is almost certainly not a brown recluse. Outside the other areas means it’s not even related to the brown recluse. If you have a specimen from inside the brown recluse zone (or if you think the experts are wrong about your particular spider even though you aren’t in brown recluse territory) then let’s try to figure out if it’s not a brown recluse.

Let’s take a look at its legs.

Loxosceles Rhymes With Isosceles for a Reason

Loxosceles rhymes with isosceles, which you may remember from geometry is a type of triangle. The words are similar for a reason.

Loxosceles actually means slanted legs. If you look at a brown recluse from the side you can see how the body sits low and the legs angle up to a point. It’s that angular, slanted shape of its legs that give the brown recluse its scientific name.

Two more distinct features of brown recluse legs:

  • No spines: Unlike many other spider species, loxosceles does not have spikes or spines on its legs.   They are smooth.
  • One color: Some spiders have multi-colored legs, but loxosceles keeps it solid—no stripes and no patterns.

If your spider doesn’t have these legs then it’s definitely not a brown recluse. If you find these leg characteristics similar to your spider then look into its eyes, all 6 of them.

The Eyes of the Brown Recluse

Assuming you’re in brown recluse country and you have a spider with a low-slung body on angled, smooth, solid color legs, the next thing is to look your spider in the eye.

Brown recluse spiders have 6 eyes.   They’re paired in what are known as diads and arranged on the front and sides of the brown recluse’s head (see image upper left and bottom). Other spider species might have 8 eyes or they might have 6 eyes arranged in two triads (groups of three).

These guys are tiny, so seeing their eyes without a microscope is going to be difficult. If you have trouble with the fine print like me, you’ll probably at least want a magnifying glass.

You can’t be sure if it is a brown recluse based only on the eyes, but if the eyes aren’t in the proper pattern then it’s definitely not a brown recluse.

You got here because your spider had smooth, angled legs of all one color and you found it in brown recluse territory. Does your spider also have the proper peepers? If not, you’re done here. If it does, move on to the rest of the body.

If the Legs and the Eyes Look Good, How About the Rest of the Body?

There are two more characteristics you need to see for this to be a loxosceles:

  • The body (without legs) has to be small, no more than 3/8 of an inch.
  • The abdomen (big round part on the backside) needs to be a little fuzzy with very fine hairs and a solid color.
See also:  How Long Can Spiders Live Without Food?

Brown recluses are boring when it comes to fashion. They like solids. They aren’t into patterns or stripes and that is obvious on their legs and abdomens.   There is one common brown recluse fashion statement that everyone seems to know about: the fiddles on their backs.

Isn’t It Called a Fiddleback for a Reason?

The one feature most commonly talked about in brown recluse descriptions is the violin-shaped mark on its back.   Not all loxosceles are brown recluses, but they all have similar venom. Not all brown recluses have the classic violin mark. Even if it’s there, you might not be able to clearly see it.

Worse yet, there are a bunch of spiders that also have the violin marking on their backs and they’re not brown recluses. In many cases, they’re not even venomous to humans. The worst-case scenario is that a doctor thinks you’ve been bitten by a brown recluse when you have not.

There’s no antivenin—no specific treatment—for brown recluse bites, but many wounds that are diagnosed as brown recluse bites are actually infections and could be treated with antibiotics as long as your doctor diagnosis it correctly.

Counting on the fiddle to identify a brown recluse is a bad idea.

University of Kentucky. Entomology. Brown Recluse Spider.

Tips to Identify a Brown Recluse

The brown recluse spider is a venomous spider that is often times referred to as the violin or fiddle back spider, due to the fact that it carries a violin-shaped marking on its back. This spider is also unusual because it has only six eyes, whereas most spiders have eight. Knowing how to identify a brown recluse spider could help you avoid any unpleasant encounters. Here are a few tips to help.

Where do brown recluse spiders live?

These spiders are commonly found in 15 states: Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Ohio, Oklahoma, Tennessee and Texas. Brown recluse spiders may be transported from one location to another in boxes and other items.

What color is it?

A brown recluse has a tan to brown colored body. Its legs are the same light-colored brown with no other markings.

How can you locate its distinctive markings?

When determining how to identify a brown recluse spider, one of the most common ways is to look at the marking on its body. The violin shape should be relatively easy to distinguish if you look closely. This violin shape stands out because it’s much darker than the rest of the body. The marking is located on the top area of the spider, also known as the cephalothorax.

Does the body have any hair?

The brown recluse’s body is covered with a number of fine, small hairs that look somewhat like fur. The legs of the spider are smooth.

How big is it?

These spiders don’t grow to be very large. With the legs extended, the brown recluse is approximately the diameter of a quarter. If the spider you’re looking at is larger than this, you’re probably looking at a different type of spider.

What do their webs look like?

Brown recluse spider webs are often hidden, so you may not see them. These webs also aren’t used to catch prey like many other species of spiders use their webs for. Brown recluse webs are loose and sticky. The color of their web is typically off-white or grayish. Webs are usually found at ground level and are poorly organized.

Where did you find the spider?

As their name might imply, these spiders prefer to live in dark, dry, undisturbed areas. Here are a few places you are likely to find them:

piles of stone or rubble

hollow sections of trees

stored boxes or newspapers

shoes (especially those kept outside)

folds of drapery

What if I’ve been bitten?

Learning how to identify a brown recluse spider by its bite can be a challenge. Bites from the recluse are rare, despite the horror stories. Their bites are relatively painless, so you might not even know that you’ve been bitten until hours later. If you notice two fang-like punctures at the site of a bite and the area begins to form an appearance of a blister, it’s advisable to seek medical attention right away.

If you are still unsure of how to identify a brown recluse spider, call a pest management professional.





  • Home
  • The Buzz
  • Learn About Pests
  • Site Map
  • Accessibility Statement


  • Terminix Canada ®
  • Corporate Information
  • Privacy
  • Terms of Use
  • Careers


  • ServiceMaster Home
  • AmeriSpec ®
  • Furniture Medic ®
  • MerryMaids ®
  • ServiceMaster Clean ®
  • ServiceMaster Restore ®



By using our website, you agree to our use of cookies to analyze website traffic and improve your experience on our website. Learn more about the types of cookies we use by reviewing our updated Privacy Policy.

No comments

Добавить комментарий

Your e-mail will not be published. All fields are required.