Most spider bites heal on their own within a few days to a week with basic home care: clean the wound, reduce swelling, and manage pain. The vast majority of spiders produce bites no worse than a mild bee sting. What matters is acting quickly with the right first aid, keeping the area clean as it heals, and knowing the warning signs that mean you need medical attention.
First Aid in the First Hour
Start by washing the bite with mild soap and water. This is the single most important step because it reduces the risk of infection, which causes more problems than most spider venom. After cleaning, apply an antibiotic ointment to the area. Reapply the ointment three times a day for the first few days.
Next, place a cool compress on the bite for 15 minutes each hour. A clean cloth dampened with cold water or wrapped around ice works well. This slows swelling and dulls the pain. If the bite is on your arm or leg, elevate it above heart level when you can, especially while icing. Elevation helps fluid drain away from the area and keeps swelling from building up.
Managing Pain, Swelling, and Itching
Over-the-counter pain relievers like ibuprofen or acetaminophen handle most spider bite discomfort. Ibuprofen also reduces inflammation, so it does double duty. If the bite is itchy or the swelling is significant, an oral antihistamine like diphenhydramine or cetirizine can help. Diphenhydramine tends to cause drowsiness, which can be useful if the bite is keeping you up at night, while cetirizine is less sedating for daytime use.
Resist the urge to scratch. Scratching breaks the skin and introduces bacteria, turning a minor bite into an infected wound. If itching is persistent, a cool compress usually provides more relief than scratching ever does.
What a Normal Bite Looks Like as It Heals
A typical spider bite starts as a small red bump, sometimes with two faint puncture marks. It may look similar to a wasp sting. Over the first day or two, you can expect mild redness, some swelling, and tenderness around the site. These symptoms peak within 24 to 48 hours for a common (non-venomous) bite.
By day three or four, the redness should be shrinking rather than spreading. Any pain should be fading. Most bites from common house spiders resolve completely within a week, leaving little or no mark behind. If your bite follows this pattern, your home care is working.
Brown Recluse Bites: A Different Timeline
Brown recluse bites don’t always look alarming at first, but they follow a distinct pattern. Within three to eight hours, the bite area becomes sensitive, red, and feels like it’s burning. The skin may develop a bullseye pattern or turn bluish from bruising.
Between three and five days, one of two things happens. If the spider injected only a small amount of venom, the discomfort fades and the bite heals normally. If more venom was injected, the pain continues and an ulcer forms at the bite site. In severe cases, by one to two weeks the skin around the ulcer breaks down into an open wound that can take months to fully close. By three weeks, the majority of brown recluse bites have healed, typically leaving a thick black scab over the wound site.
If you suspect a brown recluse bite, try to capture or photograph the spider for identification. Knowing the species changes how a medical provider manages the wound at each stage. Left untreated, brown recluse wounds can lead to serious infection or scarring, but with proper care, most people recover fully.
Black Widow Bites: Systemic Symptoms
Black widow bites cause a different kind of problem. The bite itself may feel like a pinprick, but within 15 minutes to an hour, a dull, spreading muscle pain radiates outward from the bite. Where you feel that pain depends on where you were bitten: upper body bites tend to send pain into the chest, while lower body bites cause intense abdominal cramping.
This is where black widow bites get tricky. The abdominal or chest pain can be severe enough to mimic appendicitis, gallbladder problems, or even a heart attack. Other symptoms that can develop include difficulty breathing, high blood pressure, heavy sweating, nausea, vomiting, muscle rigidity, and facial swelling. Black widow bites require medical treatment. The symptoms are caused by the venom affecting your nervous system, and a healthcare provider can offer pain management and muscle relaxants to get you through the worst of it.
Signs That Need Medical Attention
Not every spider bite is a simple bump. Get medical care right away if you notice any of the following:
- Spreading redness or red streaks moving outward from the bite, which signals infection traveling through your lymphatic system
- A growing wound at the bite site, especially if the center is darkening or forming an ulcer
- Severe pain or abdominal cramping that goes beyond localized soreness
- Difficulty breathing or swallowing, which may indicate an allergic reaction
- Fever developing in the hours or days after the bite
You should also seek care if you’re unsure whether the spider was venomous. If you can safely bring the spider (even if it’s been crushed) or a clear photo of it, that helps with identification and guides treatment decisions.
What Not to Do
Some common instincts actually make spider bites worse. Don’t apply a tourniquet or try to cut open and “suck out” venom. These techniques don’t work and risk additional tissue damage or infection. Don’t apply heat to the bite in the first couple of days, as warmth increases blood flow to the area and can worsen swelling. Stick with cool compresses instead.
Avoid popping any blisters that form over the bite. Blisters are your body’s natural bandage, protecting the healing skin underneath. Breaking them open creates an entry point for bacteria. If a blister breaks on its own, clean the area gently and apply antibiotic ointment.
Keeping the Bite Clean as It Heals
For the first several days, continue cleaning the bite once or twice daily with soap and water, followed by a thin layer of antibiotic ointment. Cover the area with a loose bandage if it’s in a spot that rubs against clothing or gets dirty easily. Change the bandage daily or whenever it gets wet.
Watch the bite each day for changes. A healthy healing bite will gradually shrink in redness and become less tender. If the redness expands, the center darkens, or you notice pus, those are signs of infection that need professional treatment. Taking a daily photo of the bite with something for scale (like a coin placed nearby) gives you an objective record of whether it’s improving or getting worse.