It may have only taken one radioactive spider bite for Peter Parker to become Spider-Man, but everyone else can rest easy: Spider bites are rare, and most of the time, they can be treated at home. Spiders don’t carry diseases, the way ticks and mosquitoes do, and in the United States, where thousands of species of spiders live, there are only a few venomous types that cause concern—notably, the black widow and the brown recluse.
UNC Health family medicine doctor LeRon Jackson, MD, spun a web of information about what to do if a spider bites you.
Caring for a Spider Bite at Home
You may not even realize that you were bit by a spider, as some of the bites can be painless. In some cases, the bite site may look and feel similar to any other bug bite—red, swollen, itchy or painful—but there can be a few signs that it was a spider.
“There are usually two puncture marks rather than one,” Dr. Jackson says. “They tend to be slightly larger than mosquito bites. They might be the size of a nickel, but not always.”
If you notice a bite, you can start with basic care at home.
“Wash the area and apply ice,” Dr. Jackson says. “Elevate the area if the bite was on an arm or leg, which helps with the swelling. If you’re itchy, you can use a topical cream or take an antihistamine.”
As with other insect bites or stings, resist the urge to pick or scratch.
“If it’s forming a blister, don’t squeeze or pop it,” Dr. Jackson says.
For most people, these steps will be all that you need to do, as long as symptoms don’t worsen.
When to Seek Care for a Spider Bite
Black widow and brown recluse spiders can inject a venom with their bite that can cause additional symptoms. Black widow spiders are shiny and black with a red hourglass shape on their belly, while brown recluse spiders are known for a dark brown violin-shaped marking on their back.
If you know you were bit by one of these spiders, call your primary care provider or go to urgent care. It’s especially important for young children and older adults to be evaluated after these spider bites, Dr. Jackson says, as the venom might affect them more severely.
If you don’t know what bit you, you should go to urgent care if your initial symptoms worsen or you start experiencing new symptoms in the hours after a bite.
“A black widow bite can cause muscle pain and cramping, headache, nausea, fever and a general sense of being unwell,” Dr. Jackson says. “With a brown recluse bite, the main thing to watch for is if the wound is changing rapidly. You might have extreme pain at the bite, swelling, redness and start to see a very large blister or sore.”
It is extremely rare for these bites to cause serious illness or death, but a healthcare provider should evaluate the severity of the bite, check for infection and treat your symptoms, particularly any skin wounds.
If you’re having extreme muscle cramping or pain, your provider may give you medication. In cases with severe symptoms, such as seizures or trouble breathing, you could receive an antivenom medication for a black widow spider bite (there is not antivenom for brown recluse bites).
Some severe brown recluse bites may need surgical removal of dead tissue.
Other skin lesions, such as a boil or abscess, can look like brown recluse bites, so Dr. Jackson says people sometimes worry they’ve been bit by a spider when they haven’t—but that they should seek care as well.
“If you have any skin concerns that aren’t healing or are worsening, call your doctor or go to urgent care,” Dr. Jackson says.
Preventing Spider Bites
Spiders do not want to bite you. They tend to bite when they get trapped between your skin and another object, such as clothing. If you see a spider on you, flick it off rather than crushing it, which could cause it to bite.
“After you spend time in the outdoors, check your skin and shake out your clothing,” Dr. Jackson says. “If you can, wear long sleeves or pants to keep your extremities covered.”
Insect repellents have ingredients that are meant to repel mosquitos, ticks and fleas, but they may provide some protection against spiders.
You may not be able to prevent a bite, but simply being aware that spiders hang out in a variety of places can help you from disturbing them unnecessarily. Spiders may find homes in piles of rocks, gardening equipment or stored firewood, so be careful when picking up items that have been sitting in your yard and wear work gloves.
They can also find places to live in your home, especially among boxes or storage tubs that aren’t moved often.
“There can be spiders in places you don’t expect them—basements, attics, storage areas,” Dr. Jackson says.
It can be helpful to learn what black widow and brown recluse spiders look like, but again, these bites are rare.
“Most spiders bites are not threatening,” Dr. Jackson says. “They’re easily managed and taken care of.”
Worried about a bug bite? Talk to your doctor or find one near you.