What to do
Routine spider bite
- 1Clean the bite with mild soap and water.
- 2Apply an antibiotic ointment to help prevent infection.
- 3Apply a cool compress over the bite (about 15 minutes at a time) to reduce pain and swelling.
- 4Elevate the area if it's on an arm or leg.
- 5Use an over-the-counter pain reliever if needed.
- 6Watch the bite over the next hours and days for spreading, worsening, or the symptoms below.
If a black widow or brown recluse is suspected
- 1Seek emergency/medical care. Bring a description or a safe photo of the spider if you have one.
- 2Clean and cool the bite as above while arranging care.
- 3Keep the person calm and still, and monitor breathing.
When to use it
- Reaching into woodpiles, sheds, gloves, boots, and dark corners — where recluses and widows hide — is when bites happen.
- Reassuring a scout the usual bite is minor, while knowing the two that aren't.
- Recognizing a brown-recluse sore or black-widow cramping early enough to get care.
Common mistakes & safety
- Most spider bites need only basic wound care. Don't panic — but do watch for the danger signs.
- Black widow and brown recluse bites need medical care — and so does a bite you can't identify that has severe pain, cramping, or a growing wound.
- A brown-recluse bite can slowly turn into an expanding, darkening ulcer. A wound that keeps getting bigger or turns purple/black over days is a see-a-doctor sign.
- Black-widow cramping can be mistaken for a stomach emergency. Severe belly rigidity after a bite is a reason to get seen, not to wait it out.
- Trouble breathing or swallowing, or spreading redness and streaks, is an emergency — call for help.
- Don't cut, suck, or apply a tourniquet. As with snakebite, those "remedies" don't help and can harm — clean, cool, and get care.
- Prevention: shake out boots, gloves, and sleeping bags; wear gloves in woodpiles; don't reach blindly into dark spaces.
Going deeper
- Judge by symptoms, not a positive ID. The black widow is glossy black with a red hourglass underneath; the brown recluse is brown with a darker violin-shaped mark — but most people never see the spider.
- Why the recluse wound grows. Its venom can kill tissue around the bite, producing a slowly enlarging sore — which is why "the wound is getting bigger" is a specific warning to act on.
- Reaction vs. envenomation. As with stings, a rare person can have an allergic (whole-body) reaction to a spider bite separate from the venom — trouble breathing means 911.
Official source
Spider bites: first aid — Mayo Clinic →This is general first-aid information, not a substitute for professional care. A suspected widow or recluse bite needs medical evaluation.