A bite from a brown recluse spider can be mild or severe and may require medical attention. The toxins from this spider’s bite can cause tissue death.
Bites from the brown recluse spider almost never result in death but can cause serious skin damage, nausea, and muscle pain. With proper care, mild bites resolve within days to weeks, while more severe cases can take months to heal.
A bite from the brown recluse spider requires first aid, and if necessary, professional medical attention. Treatment often includes cleaning the affected skin, pain relievers, and icing.
Keep reading to learn the symptoms and stages of a brown recluse spider bite, how to identify the spider, and when to seek help.
What’s in the bite?
Even though this spider’s size maxes out at about a half-inch, its venom is more toxic than that of a rattlesnake. Luckily, the brown recluse is only capable of releasing a little into our system.
Here are two key toxins in the venom:
- Sphingomyelinase D has the potential to destroy skin tissues.
- Hyaluronidase can speed the venom’s penetration into tissue.
A brown recluse’s venom can destroy blood vessels, tissue, and nerves. As a result, the skin tissue can die, a phenomenon called skin necrosis.
Prompt treatment can slow these effects and allow your skin to begin healing faster.
Brown recluses have very small fangs, and their bite is usually painless. Unless you saw it happen, at first, you might not even be aware that a spider has bitten you.
You may start to notice a red, tender, and inflamed area about 2 to 8 hours after the spider bit you. Over the course of the next several hours, the irritation may cause a burning sensation.
The bite may appear as
After 3 to 5 days
In some people, the brown recluse’s venom is localized to only the area where the spider bit you. If the spider injected minimal venom and you’re healthy, the discomfort usually goes away in a few days.
But for others, the venom spreads. This causes the wound to expand, usually over a period of several days to weeks. Some people will develop a blister, and then a “necrotic lesion” due to the spider’s bite. This means the bite causes an ulcer or open sore, and tissue begins to die.
This may look like the following:
- dry, sinking patch of skin
- bluish-appearing patch of skin
- redness around the lesion with a pale center
- central blister
After 1 to 2 weeks
For mild bites, you should be mostly healed by 3 weeks or see a drastic reduction in inflammation.
But if you have a more severe bite, the spider’s toxin will continue to break down the skin, especially if untreated. The site of the wound may start to develop necrotic (dead) tissue called eschar. This looks like a big, black scab covering the wound area.
3 months later
Most brown recluse bites will heal fully, without complications, in 3 months or less.
In very rare cases where a lot of venom was delivered, necrosis in the wound can extend beyond the skin and into the muscles. If tissue death continues to occur or has already affected a large area, you’ll need to be evaluated by a surgeon. Surgery may be required to remove or repair excess dead tissue.
If the wound hasn’t responded to treatment or symptoms don’t align with the typical presentation of a brown recluse bite, it may be time for a differential diagnosis. Your doctor will consider other potential culprits of your symptoms, like another type of insect bite or a separate skin condition.
Severe reactions to a brown recluse spider bite
Some people have severe or life threatening reactions to brown recluse bites. These responses to the bite are more likely in those with compromised immune systems, including children and older adults.
Severe reactions to a brown recluse bite can include the following symptoms:
If you or a loved one is experiencing the above symptoms, seek emergency medical assistance. This may be a sign of anaphylactic shock, a life threatening allergic reaction.
The brown recluse spider is usually no larger than a half-inch in length, including its eight thin legs. It’s a plain tan or brown color, with no stripes or patterning. Adults almost always have a dark, “violin-shaped” mark on their heads. For this reason, the brown recluse is sometimes called the “violin spider” or “fiddleback spider.”
Brown recluses have six eyes instead of the usual eight. These eyes are arranged in a horizontal row of 3 pairs on the face.
If you see a brown recluse or signs of them, like when they “shed” their skins, collect evidence (if safe to do so). If you have a picture of the spider, this could help a doctor determine if a brown recluse bit you, and if you need medical treatment.
If bitten, it’s important to:
- avoid touching or scratching the bite
- clean the affected area with soap and water
- apply a fresh, non-stick bandage
Do not attempt to extract the spider’s venom. While first-aid procedures for several types of bites and stings involve trying to extract poison or venom, the
Not all bites require medical treatment, and some can be treated at home. Keep close tabs on the bite. If it causes acute burning and pain or is getting worse instead of better after a few days, see a doctor right away.
Doctors will often use the RICE method (rest, ice, compression, and elevation) to treat a suspected or confirmed brown recluse bite.
In addition to the first aid steps of cleaning and dressing the wound, here are some key steps:
- applying cloth-covered ice packs for 10 minutes at a time to keep the spider’s venom from spreading
- elevating the affected area and refraining from touching it
- taking an over-the-counter nonsteroidal anti-inflammatory drug (NSAID) or a stronger prescription
- receiving a tetanus shot if yours isn’t up to date
Depending on the severity of your symptoms, further treatments may be used.
- antibiotics to treat a confirmed or suspected infection
- special wound dressings or ointments to promote healing and reduce pain
- rarely, skin grafts or wound debridement to repair larger areas of damaged skin
Seeking treatment as soon as possible can help reduce the need for more invasive treatments.
Brown recluse spider bites can be hard to diagnose.
The bite can resemble a lot of other medical conditions, including:
- staph infection
- pressure ulcers
- wounds due to diabetes
- other spider or insect bites
- an allergic skin reaction to something else
Geographical location is an important consideration when considering a potential brown recluse bite. If you don’t live or haven’t traveled to a place where brown recluse spiders live (the south-central United States), then your bite is probably due to something else.
The “NOT RECLUSE” diagnostic criteria
Some doctors may use the mnemonic NOT RECLUSE to determine if the bite could or couldn’t be from a brown recluse. This can help you (and them) remember the criteria for which the spider’s bite is judged.
The bite usually isn’t from a brown recluse if it has the following characteristics:
- Numerous. A brown recluse usually only bites once — not multiple times.
- Occurrence. Brown recluses aren’t aggressive. Unless you’ve been in a place where they tend to hide or live, it’s not likely one bit you.
- Timing. Brown recluses only bite in months when they’re active — usually from April to October.
- Red center. Brown recluse bites usually have a pale center with redness around the bite area.
- Elevated. Brown recluse bites are usually flat — if the area is elevated, it’s not likely a brown recluse bite.
- Chronic. A bite from a brown recluse will usually heal within 3 months.
- Large. A brown recluse bite is rarely larger than about 5 inches across. If the bite is larger, it could be from something else.
- Ulcerates too early. Most brown recluse spider bites won’t ulcerate until 1 to 2 weeks after the bite occurs.
- Swollen. Brown recluse spider bites don’t usually cause significant swelling unless they’re on the face or feet.
- Exudative. Brown recluse bites don’t usually leak or cause exudate (pus). They’re more blistering or scab-like in nature.
“Recluse” is an appropriate term for describing these shy spiders, which avoid light and hide in dark crevices. Brown recluse spiders aren’t aggressive by nature and will only bite if feeling threatened or trapped.
We don’t advise poking around for them — it’s best to leave this to a professional.
Ways you can try to avoid brown recluse bites include:
- Reduce clutter in your home wherever possible. This includes no piles of newspapers or old cardboard boxes.
- Keep shoes and clothes off the floor. Shake out your shoes before wearing to ensure spiders aren’t in them.
- Store items in air-tight plastic containers. This stops spiders from getting into them.
- Wear long sleeves and gloves while sorting through old materials. This includes boxes in an attic. Spiders can’t usually bite through clothing, so this can offer some protection.
- Ensure cracks and holes in your home’s foundation and structure are properly sealed. Spiders can enter through these areas.
- Place flat glue traps in areas where spiders may live in your home. Examples include along baseboards where the wall and floor meet, as well as around areas of clutter.
Professional exterminators can also help you get rid of these and other pests that may cause bites and stings.
Want to know more about the brown recluse spider’s distinguishing features? We’ve got you covered.
|These spiders typically live in the south-central portion of the United States, including Texas, Iowa, Oklahoma, Tennessee, and Georgia. It’s rare but possible that the spider gets accidentally transported outside its region.
|When they appear
|Brown recluses go into “harborages” for the winter, which is any hidden area the spider can find shelter in. They emerge between April and May, usually going away around October.
|Where they live
|These spiders look for warm crevices to crawl under, like insulation, cardboard boxes, or between pages of newspapers. Outdoors, they often live under the bark of dead trees or under rocks. They may crawl into shoes or bedding and bite you when they accidentally become wedged against your skin.
|What they eat
|Brown recluses do spin webs, but they don’t use them to trap their prey. Instead, the web is used as a home or refuge. They eat crawling bugs, like cockroaches, ants, and crickets.
|Brown recluses live long lives, sometimes up to 5 to 7 years. They can go for extremely long periods without eating.
Because of their size and brown-ish appearance, the wolf spider is often mistaken for the brown recluse.
But the wolf spider is not venomous to humans. They can still bite, which leaves a small red bump that usually goes away in a few days. You’ll need to clean and treat the bite, so it doesn’t become infected and watch out for signs of an allergic reaction.
Here’s a breakdown of major differences between these two arachnids:
|Brown recluse spider
|1/4-1/2 inch size
|1/2-2 inch size
|Venomous bite, considered very dangerous to humans
|Venomous bite, not considered dangerous to humans
|plain tan or brown, with violin-shaped dark mark on head, covered in thin hairs
|gray with dark brown or gray markings on body and legs, slightly furrier appearance than brown recluse
|spins webs, hunts on ground
|doesn’t spin webs, hunts on ground
Brown recluse spider bites are often painful and can cause skin tissue to die (skin necrosis). It may take several hours to notice that you’ve been bitten.
Implementing first aid can help reduce symptoms. Clean the skin with soap and water, and use a non-stick bandage. Icing and elevation can help prevent the toxin from spreading. OTC pain medications can help with discomfort.
Avoid itching the bite and do not attempt to extract venom.
With proper care at home, most brown recluse bites will heal on their own over the course of several weeks. If your bite is especially painful or skin inflammation is spreading, see your doctor for evaluation and further treatment.