Most spider bites heal on their own within one to three weeks with basic wound care: cleaning, cooling, and keeping the area elevated. The vast majority of spiders lack venom strong enough to cause serious harm, and treatment at home is straightforward. The exceptions are bites from black widows and brown recluses, which can cause systemic reactions or slow-healing wounds that need medical attention.
Immediate First Aid Steps
Start by washing the bite with mild soap and water. This is the single most important thing you can do early on, because it reduces the risk of bacterial infection, which is actually more common and sometimes more dangerous than the venom itself.
After cleaning, apply a cool cloth or an ice pack wrapped in a clean cloth to the bite for 15 minutes each hour. Cold slows the spread of venom and reduces swelling. If the bite is on your hand, arm, foot, or leg, keep the limb elevated above heart level when you can. Elevation helps limit swelling and keeps fluid from pooling around the wound.
Avoid squeezing the bite, applying heat, or trying to suck out venom. None of these help, and some can make the wound worse.
Managing Pain and Itching at Home
An over-the-counter pain reliever like ibuprofen or acetaminophen handles the soreness from most bites. If the area is itchy, an antihistamine such as diphenhydramine (Benadryl) or cetirizine (Zyrtec) can help. These are the only medications with broad medical support for home treatment of spider bites.
You’ll find plenty of advice online about baking soda pastes, vinegar, drawing salves, and essential oils. There’s no clinical evidence that any of these neutralize spider venom or speed healing. Stick with the basics: keep it clean, keep it cool, and manage your symptoms with standard medications.
How Long Healing Takes
A typical, non-dangerous spider bite follows a predictable path. You’ll see redness and mild swelling for the first day or two, followed by gradual improvement. Most bites resolve completely within one to three weeks without any special treatment.
Brown recluse bites have a wider range of outcomes. If the spider injected only a small amount of venom, discomfort typically fades within three to five days. In more severe cases, an ulcer forms at the bite site within the first week, and the surrounding skin can break down between days 7 and 14. These wounds may take several months to heal fully and sometimes require skin grafting. The majority of brown recluse bites, though, heal within about three weeks.
Brown Recluse Bites and Wound Care
Brown recluse venom can destroy a small patch of skin, creating a necrotic (dead tissue) wound that expands outward from the bite. The venom’s tissue-destroying activity is temperature-dependent, which is why continued cold compresses are especially important with these bites. Keep applying cool compresses until the wound stops growing.
Medical care for a progressing brown recluse wound typically involves keeping the area elevated and immobilized, cleaning and removing dead tissue as needed, and monitoring for deeper complications. Various treatments have been tried over the years, including steroids, certain anti-inflammatory drugs, and even surgical removal of the wound. None have strong evidence of improving outcomes in controlled studies. The current standard is conservative wound care: keep it clean, keep it cool, keep it still, and let the body heal. Patients with large or deep wounds may eventually need to see a specialist for skin grafting.
Black Widow Bites and Systemic Reactions
Black widow venom works differently. Rather than destroying skin at the bite site, it affects the nervous system and muscles throughout the body. Symptoms can include intense cramping pain in the abdomen, chest, shoulders, and back, along with sweating, nausea, vomiting, headache, and elevated blood pressure. The abdominal pain can be severe enough to mimic a surgical emergency.
Other signs include restlessness, anxiety, muscle rigidity, difficulty breathing, and a diffuse rash. These symptoms require medical attention. An antivenom exists specifically for black widow bites and is given by injection in a hospital setting. A single dose is usually sufficient, though a second dose is sometimes needed. Elderly patients tend to have more severe reactions and are often treated with antivenom as a first-line approach.
Signs the Bite Is Infected
Any break in the skin can let bacteria in, and spider bites are no exception. A secondary infection called cellulitis is one of the most common complications. Watch for these warning signs:
- Skin changes around the bite: increasing redness, warmth, swelling, and tenderness that seem to be spreading
- Infection-specific clues: red streaks radiating outward from the bite, blisters, or yellow or pus-like drainage
- Flu-like symptoms: fever, chills, nausea, or swollen lymph nodes
A useful trick is to take a washable marker and draw a border around the redness on your first day. If the redness, swelling, or blistering expands beyond that border, that’s a clear signal to seek medical care promptly.
It Might Not Be a Spider Bite
Here’s something most people don’t realize: many “spider bites” aren’t spider bites at all. A significant number turn out to be MRSA, a type of antibiotic-resistant staph infection that produces skin lesions strikingly similar to spider bites.
This misidentification isn’t limited to everyday guesswork. In the early 2000s, outbreaks of skin infections at multiple U.S. military bases in Georgia, California, and Texas were initially blamed on spider bites. When pest management consultants inspected the facilities, they found no evidence of spiders. Bacterial cultures confirmed MRSA as the actual cause. The same thing happened at Fort Benning in 1997, where brown recluse bites were blamed for lesions despite no recluse spiders being found in the area.
If you didn’t see a spider bite you, and especially if you’re developing a painful, swollen, pus-filled lesion, consider the possibility that it’s an infection rather than a bite. MRSA infections need antibiotics, not wound care for venom, so the distinction matters.
When Emergency Care Is Needed
Most spider bites are a nuisance, not an emergency. But certain symptoms signal a serious reaction that needs immediate medical attention:
- Severe muscle cramping or rigidity, especially in the abdomen, chest, or back
- Difficulty breathing
- Rapid heart rate or high blood pressure
- Spreading rash, seizures, or fainting
- Severe nausea and vomiting combined with other symptoms
These are signs of systemic envenomation, meaning the venom is affecting your whole body rather than just the bite area. This is most associated with black widow bites but can occur with brown recluse bites in rare, severe cases where the venom triggers widespread inflammation, blood clotting problems, or kidney damage.
Tetanus and Spider Bites
Spider bites are puncture wounds, which the CDC classifies as “dirty or major wounds” for tetanus risk. If you’ve completed your primary tetanus vaccine series but your last booster was five or more years ago, a booster is recommended. If your vaccination history is unknown or incomplete, you should get vaccinated regardless of the wound type. People with compromised immune systems may also need a tetanus immunoglobulin injection for added protection.