Most spider bites can be treated at home with basic first aid, and the majority heal within one to three weeks without complications. The key steps are cleaning the wound, managing swelling with ice, and watching for signs that something more serious is happening. Only a small number of spider species cause bites that require medical attention, but knowing what to look for can make the difference between a smooth recovery and a dangerous delay.
Immediate First Aid Steps
As soon as you notice a bite, or suspect one, start with these steps:
- Wash the area with warm, soapy water using a gentle cloth. This is the single most important thing you can do to prevent infection. Rinse thoroughly. As emergency physicians put it: the solution is dilution.
- Apply ice for 15 minutes on, then 15 minutes off. Use a bag of ice or a cold pack wrapped in a clean cloth. Repeat as needed throughout the day. This reduces both swelling and pain.
- Apply antibiotic ointment to the bite three times a day to help prevent secondary infection.
- Elevate the area if possible. If the bite is on your hand or foot, prop it up above heart level to limit swelling.
- Take an over-the-counter pain reliever as soon as you can. For adults, 500 to 1,000 milligrams of acetaminophen or 400 to 600 milligrams of ibuprofen will help reduce inflammation, redness, and pain. Taking these early makes a noticeable difference because they slow the inflammatory response before it peaks.
Calamine lotion or a hydrocortisone cream can also help with itching and irritation around the bite site. Most bites from common house spiders or garden spiders will improve within a few days with just this level of care.
How to Tell if a Bite Needs Medical Attention
The vast majority of spider bites look and behave like any other bug bite: a red, slightly swollen bump that itches or stings for a day or two. What makes some bites dangerous isn’t the wound itself but the venom spreading through your body. Watch for these warning signs:
- Severe pain that keeps getting worse rather than fading
- Abdominal cramping or rigid stomach muscles (this is common with widow spider bites and is sometimes mistaken for appendicitis)
- Nausea, vomiting, tremors, or heavy sweating
- Difficulty breathing or swallowing
- A wound that keeps growing in size over several days
If you experience any of these, get medical care immediately. Children, older adults, and people with heart disease or weakened immune systems are at higher risk of severe reactions and should be evaluated sooner rather than later.
Brown Recluse Bites and Skin Breakdown
Brown recluse bites follow a distinctive timeline. In the first three to five days, if the spider injected only a small amount of venom, the initial discomfort usually fades on its own. But if a larger dose of venom spread beyond the bite area, the pain persists and an ulcer forms at the bite site.
Between seven and 14 days, in severe cases, the skin around the ulcer breaks down into an open wound. This is the necrotic tissue damage that brown recluse bites are known for, and these wounds can take several months to fully heal. The good news is that the majority of brown recluse bites heal within about three weeks without reaching that severe stage.
If you suspect a brown recluse bite and notice the wound growing or darkening over several days, don’t try to manage it at home. A growing wound needs professional evaluation. You may need wound care to remove damaged tissue and prevent deeper infection.
Black Widow Bites and Systemic Symptoms
Black widow bites are a different kind of problem. The bite itself may not look alarming, but the venom affects your nervous system. Symptoms tend to spread outward from the bite: pain and muscle spasms that start near the wound can move to your abdomen, back, and chest. Severe abdominal rigidity, heavy sweating, nausea, and elevated blood pressure are hallmarks of a significant envenomation.
Antivenom exists for black widow bites and is given to patients with systemic symptoms, meaning symptoms that have moved well beyond the bite site. The threshold for using it is generally based on how severe and widespread the muscle spasms and pain become. Children, older adults, and people with cardiovascular disease may need antivenom earlier in the process because they’re less able to tolerate the stress the venom puts on the body.
Preventing Infection After a Bite
One of the biggest real-world risks with any spider bite isn’t the venom. It’s the secondary bacterial infection that develops when the wound isn’t kept clean. Spider fangs can introduce bacteria into the skin, and scratching an itchy bite with dirty hands makes it worse.
Keep applying antibiotic ointment three times daily for the first several days. Watch for signs of infection: increasing redness that spreads outward from the bite, warmth, pus, or a fever. A red streak running away from the wound toward your torso is a sign the infection is spreading and needs prompt treatment. Many skin infections that people assume are spider bites are actually staph infections, including MRSA, so if a “bite” keeps getting worse despite home care, it’s worth getting it checked.
Tetanus and Puncture Wounds
Spider bites that resemble puncture wounds can carry a risk of tetanus, particularly if the wound is deep or gets contaminated with dirt. CDC guidelines classify puncture wounds as “dirty or major” wounds with increased tetanus risk. If you’ve completed your tetanus vaccine series but your last booster was five or more years ago, you may be due for another one. If you’ve never been fully vaccinated or don’t know your vaccination history, it’s especially important to follow up with a provider after any significant puncture wound. The general recommendation is a tetanus booster every 10 years, but dirty wounds can move up that timeline.
What Recovery Looks Like
For a typical spider bite, you should see improvement within two to three days. The redness shrinks, the swelling goes down, and the itch or sting fades. Most bites are fully healed within three weeks. During that time, keep the area clean, avoid scratching, and continue applying antibiotic ointment if the skin is broken.
Brown recluse bites that develop into open wounds are the exception. These can take weeks to months to close, and they sometimes leave a scar. If you’re dealing with a slow-healing wound from a suspected brown recluse bite, your provider may schedule regular wound checks and give you specific dressing instructions to follow at home.
The bottom line: clean it, ice it, medicate early, and keep a close eye on it. Most spider bites are more annoying than dangerous, but the ones that aren’t will make themselves known within the first few days through worsening pain, spreading symptoms, or a wound that refuses to shrink.