Most spider bites can be safely treated at home with basic first aid, and the vast majority heal on their own within a few days. Only two spiders in North America, the brown recluse and the black widow, pose a serious medical threat. For everything else, cleaning the wound, managing pain, and watching for signs of trouble is all you need to do.
Immediate First Aid Steps
Start by washing the bite area with soap and water. This is the single most important thing you can do, because bacterial infection from the wound is actually more common than serious venom reactions. Once it’s clean, apply a cold pack wrapped in a cloth (never directly on skin) for 10 to 20 minutes at a time, three or more times a day. Cold reduces both swelling and pain in the first 48 to 72 hours.
If the bite is on an arm or leg, keep it elevated at or above heart level whenever you’re sitting or lying down. This limits swelling significantly. You can also wrap the area lightly with an elastic bandage for compression, but loosen it immediately if you notice numbness, tingling, increased pain, or coolness below the wrap. After the first two to three days, once swelling has gone down, you can switch from cold to warm compresses to help with residual soreness.
Managing Pain and Itching
An over-the-counter pain reliever like ibuprofen or acetaminophen handles the soreness from most bites. If itching is the bigger problem, an antihistamine like diphenhydramine (Benadryl) or cetirizine (Zyrtec) can help. A dab of hydrocortisone cream on the bite also calms localized itch and inflammation. For most common spider bites, like those from wolf spiders or jumping spiders, symptoms clear up on their own within a few days with just these measures.
What Not to Do
Skip any home remedy that involves cutting the bite open, trying to squeeze or suck out venom, or applying a tourniquet. None of these work, and they increase your risk of infection or tissue damage. Don’t apply rubbing alcohol, hydrogen peroxide, or bleach directly to the wound either. Stick with mild soap and water. Resist the urge to scratch, which can break the skin and introduce bacteria.
How to Tell What Bit You
Most spider bites look like a generic bug bite: a red bump with some swelling, mild pain, and maybe a little itching. Wolf spider bites sometimes leave two visible fang marks, but the reaction is still minor and localized. This describes the overwhelming majority of spider bites people encounter at home.
Brown recluse bites are different. They’re painless at first, so you may not notice one right away. Over the following hours, the site develops a distinctive pattern: a ring of redness surrounding a pale white center with a darker, bruised-looking core. Doctors sometimes call this the “red, white, and blue sign.” Without treatment, the center can blister, form a dark scab, and eventually ulcerate into an open sore. You may also feel pain radiating into your back, abdomen, or chest, along with fever and muscle aches.
Black widow bites attack the nervous system rather than the skin. The bite itself may feel like a pinprick, but within 30 to 60 minutes you can develop severe, bodywide muscle pain and cramping, particularly in the abdomen, shoulders, chest, and back. The abdominal cramping can be intense enough to mimic a surgical emergency. Stiffness and muscle spasms are hallmarks of this bite.
Signs a Bite Needs Medical Attention
Get medical care right away if any of the following apply:
- You know or suspect the spider was a brown recluse or black widow.
- The wound is growing. An expanding area of redness, especially with streaks radiating outward, suggests spreading infection or a necrotic venom reaction.
- You develop severe pain or stomach cramping that goes beyond the bite area.
- You have trouble breathing or swallowing. This can signal a systemic allergic reaction.
- Fever, rash, or dizziness appear in the hours or days following the bite.
If the area around the bite becomes increasingly warm, swollen, and tender over two to three days rather than improving, that pattern points toward a secondary bacterial infection (cellulitis) rather than venom. Cellulitis typically spreads outward in a roughly even pattern, whereas a venom-related wound often has that asymmetric, bull’s-eye appearance. Either way, worsening symptoms mean it’s time for professional evaluation.
Tetanus and Spider Bites
Spider bites that break the skin are considered puncture wounds, which fall into the “dirty or major wound” category for tetanus risk. If your last tetanus shot was five or more years ago, or if you’re unsure of your vaccination history, a booster is recommended. If you’ve had a tetanus shot within the past five years and completed the full primary series, you’re covered. This is worth checking, because most people don’t remember exactly when they last had one.
What to Expect During Healing
A typical non-venomous spider bite follows a predictable course. Redness and swelling peak within the first 24 to 48 hours, then gradually fade. Mild itching may linger for a few days as the skin heals. The whole process usually wraps up within a week. If you’re still seeing swelling or new symptoms after three to four days, something else may be going on, whether that’s an infection, an allergic reaction, or a bite from a more dangerous species than you initially thought. At that point, having a doctor look at it is the smart move.