Most spider bites can be treated at home with basic first aid: clean the wound, apply ice, and keep the area elevated. The vast majority of spiders in the U.S. produce bites no worse than a bee sting, and symptoms resolve within a few days. The two exceptions are black widow and brown recluse spiders, which can cause serious reactions that need medical attention.
Immediate First Aid Steps
Start by washing the bite with mild soap and water. Apply an antibiotic ointment to the area to help prevent infection, and repeat this three times a day for the first few days. If you can see a stinger or debris in the wound, gently remove it, but don’t squeeze the bite or try to extract venom.
After cleaning, use the RICE approach to manage swelling and pain:
- Rest the affected limb. Avoid putting stress on it for the first day or two, then gradually resume normal movement.
- Ice the bite for 15 to 20 minutes at a time, once every hour or two. Use a clean cloth between the ice and your skin.
- Compress gently with a light bandage if swelling is significant. Don’t wrap tightly. If you feel numbness or tingling below the wrap, loosen it.
- Elevate the bitten area above heart level when possible, especially in the first 24 hours.
Over-the-counter pain relievers like ibuprofen or acetaminophen can help with discomfort. An oral antihistamine can reduce itching if that becomes bothersome.
What Not to Do
Don’t apply a tourniquet, try to suck out venom, or cut into the bite. These outdated approaches don’t work and can cause additional tissue damage. Avoid applying heat to the bite site, which increases blood flow and can worsen swelling. Stick with cool compresses instead.
When the Bite Needs Medical Attention
Get medical care right away if any of these apply:
- You know or suspect the spider was a black widow or brown recluse.
- You have severe pain, especially cramping in your abdomen or chest.
- You’re having trouble breathing or swallowing.
- The wound is growing, or you see spreading redness or red streaks around the bite.
- You develop a fever.
If the bite develops into an open sore or shows signs of infection (increasing warmth, pus, or worsening redness after the first day), you may need antibiotics.
Black Widow Bites
Black widows are found throughout North America but are most common in the southern and western United States. The bite itself feels like a pinprick, and some people don’t notice it at first. Minor swelling, redness, and a target-shaped mark may appear at the site.
The real trouble starts 15 minutes to an hour later, when a dull muscle pain begins spreading outward from the bite. If the bite is on your upper body, you’ll typically feel the worst pain in your chest. A bite on the lower body tends to send pain into the abdomen. This cramping can be severe enough that people mistake it for appendicitis, gallbladder attacks, or even a heart attack.
Other symptoms can include anxiety, difficulty breathing, headache, high blood pressure, heavy sweating, nausea, muscle rigidity, and facial swelling. Pregnant women may experience contractions. In rare cases involving children, seizures can occur. If you suspect a black widow bite, go to an emergency room. Antivenom is available for cases with severe pain or life-threatening symptoms.
Brown Recluse Bites
Brown recluse spiders live primarily in the midwestern and southern United States. Their venom can destroy skin tissue, creating a wound that progresses over days and weeks in a fairly predictable pattern.
In the first three to five days, a bite with a small amount of venom may cause only mild discomfort that fades on its own. If the spider injected more venom, the discomfort continues and an ulcer forms at the bite site. Between days seven and fourteen, severe cases involve the skin around the ulcer breaking down into an open wound. This wound can take several months to fully heal.
The majority of brown recluse bites that aren’t severe heal within about three weeks. But because there’s no way to predict early on whether a bite will progress, any suspected brown recluse bite warrants a visit to a healthcare provider. The resulting skin lesion may require professional wound care to prevent complications.
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 and received your last booster less than five years ago, no additional vaccination is needed. If your last tetanus shot was five or more years ago, or if you’re unsure of your vaccination history, your doctor will likely recommend a booster. This is worth checking even for bites that seem minor.
Normal Healing Timeline
A bite from a common house spider or garden spider typically follows a simple path: redness and mild swelling for one to two days, gradual fading over the next few days, and full resolution within a week. Some itching during healing is normal.
Brown recluse bites have a longer and more variable timeline. Most heal in about three weeks. Severe cases with significant tissue breakdown can take months. Black widow symptoms, when treated, generally improve within a few days, though muscle soreness can linger for a week or more.
Watch any spider bite closely for the first 48 to 72 hours. If pain is worsening rather than improving, the redness is spreading, or you develop any systemic symptoms like fever, chills, or muscle pain away from the bite site, those are signs the bite is more than routine and needs professional evaluation.