Most brown recluse spider bites heal on their own within three weeks with basic wound care at home. Treatment focuses on keeping the bite clean, managing pain, and watching for signs that the venom is causing deeper tissue damage or, more rarely, a body-wide reaction. There is no antivenom available in the United States, so care is largely supportive.
First Aid Right After a Bite
Clean the bite with mild soap and water, then apply antibiotic ointment to help prevent infection. Place a cool cloth or ice pack on the area for about 15 minutes each hour to reduce swelling and pain. The venom’s tissue-destroying enzyme works faster at higher temperatures, so cooling the bite also helps slow the damage. If the bite is on an arm or leg, keep it elevated above heart level or at least in a neutral position.
Check that your tetanus vaccination is current. If it’s been more than five years since your last booster, a healthcare provider will typically recommend one.
What Healing Looks Like
Brown recluse bites follow a fairly predictable pattern. The area turns red and tender within three to eight hours. Over the next three to five days, if the venom has spread beyond the immediate bite, an ulcer forms at the center. In more severe cases, the skin around that ulcer breaks down between days 7 and 14, creating an open wound.
The majority of bites that aren’t severe will heal within about three weeks. A thick, black scab (called an eschar) covers the wound as it closes. Severe bites with significant tissue death can take several months to fully heal and often leave a scar.
Pain Relief and Itch Control
Over-the-counter pain relievers like ibuprofen or acetaminophen are the starting point for most bites. If pain intensifies over the first few days, your doctor may prescribe something stronger. Antihistamines can help with itching, and one study found they were associated with a reduced risk of scarring, possibly because they help limit the inflammatory cascade the venom triggers.
Wound Care for Deeper Bites
Bites that ulcerate need daily dressing changes to keep the wound clean and promote healing. Simple antibiotic ointment and a bandage work for small wounds. For deeper or more complex wounds, healthcare providers sometimes use specialized foam dressings that deliver antiseptic agents directly to the wound surface. In one clinical case, a patient whose wound wasn’t responding to standard gauze packing saw significant improvement after switching to an antibacterial foam dressing, with reductions in wound size and infection markers.
Antibiotics are only prescribed if the wound shows signs of secondary bacterial infection, such as increasing redness, warmth, pus, or worsening pain after the first week. They aren’t routinely given for every bite.
Treatments That May Do More Harm Than Good
Over the years, doctors have tried a long list of treatments for brown recluse bites, including oral corticosteroids and a drug called dapsone (originally used for leprosy). Research published in the Journal of the American Board of Family Practice found that both performed poorly. Systemic corticosteroids were associated with 45% longer healing times, while dapsone was linked to 28% longer healing and a 45% greater risk of scarring. The type of inflammation caused by the venom doesn’t respond well to corticosteroids, so even topical or injected steroids are unlikely to help. Other proposed treatments like high-dose vitamin C, electrical current, and topical nitroglycerin patches have not shown reliable benefit either.
When Surgery Is Needed
Surgery is reserved for bites where tissue has clearly died and the wound isn’t healing on its own. The key rule is timing: surgeons wait until the wound has fully stabilized and is no longer expanding. Operating too early risks cutting into tissue that’s still being affected by venom, which can make the wound larger. Most guidelines recommend waiting six to eight weeks after the bite, until the boundary between dead and healthy tissue is well defined. At that point, a surgeon can remove the necrotic tissue and, if needed, close or graft the wound.
Systemic Reactions: A Rarer but Serious Risk
Most brown recluse bites cause only local skin damage. In a small percentage of cases, the venom triggers a body-wide reaction called systemic loxoscelism. Symptoms include fever, muscle aches, nausea, vomiting, and a widespread rash. These typically appear within the first few days.
The most dangerous systemic complication is hemolytic anemia, where the venom causes red blood cells to break apart. In a review of nine patients with systemic reactions, all developed hemolysis, with hemoglobin levels dropping by an average of 3.1 g/dL. That’s roughly equivalent to losing a significant amount of blood. Hemolytic anemia tends to develop around day five after the bite. About a third of those patients also developed kidney injury, likely from the debris of destroyed red blood cells clogging the kidneys.
If you develop fever, dark or reddish urine, yellowing skin, or feel increasingly unwell after a bite, these are signs of a systemic reaction that requires hospital care. Treatment in these cases involves IV fluids, blood transfusions when needed, and close monitoring of kidney function.
Make Sure It’s Actually a Spider Bite
One important caveat: most “spider bites” aren’t spider bites at all. In a study of 182 patients who came to a medical facility believing they’d been bitten by a spider, only 3% actually had a confirmed spider bite. A full 84% turned out to have skin and soft tissue infections, most commonly caused by MRSA (methicillin-resistant staph). MRSA infections can look strikingly similar to a brown recluse bite, with a central area of redness, swelling, and tissue breakdown.
If you didn’t see the spider or can’t bring it in for identification, your doctor may treat for both possibilities. Getting the right diagnosis matters because MRSA requires antibiotics, while a true spider bite does not unless it becomes secondarily infected. If your wound is worsening, getting cultured for bacteria can help clarify what you’re actually dealing with.