Most spider bites heal on their own with basic first aid: cleaning the wound, applying ice, and managing pain with over-the-counter medication. The vast majority of spiders in North America produce bites no worse than a mild bee sting, and symptoms resolve within a few days to three weeks. The exceptions are bites from black widows and brown recluses, which can cause serious reactions that need medical treatment.
First Aid Steps Right After a Bite
Start by washing the bite with mild soap and water. This is the single most important step, since it reduces the risk of bacteria getting into the wound. Once it’s clean, apply a cool cloth or a cloth filled with ice for 15 minutes each hour. Keep the cooling going as long as swelling persists, especially in the first 72 hours. If the bite is on a hand, arm, foot, or leg, elevate that limb to help reduce swelling.
For pain, an over-the-counter pain reliever like ibuprofen or acetaminophen works well. If the area is itchy, an antihistamine such as diphenhydramine (Benadryl) or cetirizine (Zyrtec) can help. Avoid scratching the bite, which opens the skin to infection.
What Not to Do
Skip the folk remedies. Don’t try to suck venom out of the bite, cut the wound open, or apply a tourniquet. These tactics do nothing to remove venom and can cause additional tissue damage or introduce bacteria. There’s also no evidence that applying heat, essential oils, or baking soda paste speeds healing. Cool compresses are more effective because the venom compounds that break down skin tissue are temperature-dependent, meaning cold slows their activity.
Normal Healing Timeline
A typical, non-venomous spider bite follows a predictable path. You’ll notice redness and mild swelling for the first day or two, some itching as the area heals, and full resolution within one to two weeks. Even most brown recluse bites, which are among the more serious spider bites in North America, heal within three weeks. A thick, dark scab forms over the wound, and new skin grows underneath.
In severe brown recluse cases, the skin around the bite can break down into an ulcer within 7 to 14 days. These wounds may take several months to fully close and sometimes require skin grafting by a specialist. This level of severity is uncommon, but it’s why monitoring the bite over the first week matters.
Signs a Bite Needs Medical Attention
Most spider bites don’t require a doctor. But certain symptoms signal that venom is affecting your body beyond the bite site, or that an infection has set in. Get medical care if you notice any of these:
- Difficulty breathing or tightness in the chest
- Severe muscle pain or cramping, especially in the abdomen or back (a hallmark of black widow bites)
- Heart palpitations or a racing pulse
- Nausea and vomiting
- Vision problems or severe headache
- Fever or yellow discharge from the bite, which suggest bacterial infection
- A wound that keeps expanding over several days rather than shrinking
Children under 16 and adults over 60 are more vulnerable to serious reactions from black widow bites and may need hospitalization for breathing support, blood pressure management, or muscle relaxants. Black widow bites are treated with a specific antivenom in serious cases, given by injection at a hospital.
Infection vs. Venom: Why It Matters
A red, swollen, painful bump that appears days after a bite isn’t always from spider venom. Staph infections, including MRSA, are frequently mistaken for spider bites because they look strikingly similar: a raised, red, warm area that may develop a central blister or pus. Johns Hopkins Medicine notes that MRSA can look exactly like a spider bite, but the treatment is completely different. Antibiotics clear a bacterial infection, while they do nothing for venom.
If you didn’t actually see a spider bite you, and you’re developing a worsening red bump with warmth and pus, it’s worth having a doctor evaluate it rather than assuming it’s a bite. This is one of the most common misdiagnoses in emergency rooms.
Brown Recluse Bites: What Recovery Looks Like
Brown recluse venom contains an enzyme that destroys skin cells, which is why these bites can develop into open wounds. The standard approach is conservative wound care: keeping the area clean, applying cool compresses, elevating the limb, and limiting movement of the affected area with a splint if needed. The cooling is especially important in the first 72 hours, since it slows the enzyme’s activity and limits tissue damage.
Despite what you might read online, there’s no well-studied home treatment or prescription drug that reliably changes the outcome of a brown recluse bite. Medications like dapsone, steroids, and colchicine have all been tried, but no controlled studies in humans have shown clear benefit. The best approach remains basic wound care, patience, and daily monitoring until the wound stabilizes or starts improving. If the wound keeps expanding or shows signs of infection (fever, spreading redness, pus), a doctor can clean the wound more thoroughly and treat any bacterial infection that has developed on top of the original bite.
Black Widow Bites: What to Expect
Black widow bites cause a different kind of problem. Rather than skin damage, the venom targets the nervous system. The bite itself may feel like a pinprick and leave only a small red mark. Within 30 to 60 minutes, though, you can develop intense muscle cramping that spreads from the bite site. Abdominal rigidity, back pain, and chest tightness are common and can be alarming enough to mimic a heart attack or appendicitis.
Hospital treatment focuses on controlling pain and muscle spasms. In severe cases, an antivenom is available that targets black widow venom specifically. Most healthy adults recover fully, but the muscle pain can linger for days to weeks. The very young, the elderly, and people with heart conditions face the highest risk of complications.