In the United States, fewer than three people a year are estimated to die from spider bites.1Boston Children’s Hospital. Spider Bites That is far rarer than most people fear, even though venomous spiders live in many homes.
What The Numbers Show For The Most Feared Spiders
Black widows have the scariest reputation in the US, yet among more than 15,000 black widow bites reported to poison centers, none were fatal.2Poison Control. How dangerous is a black widow spider bite? Only 1 in 10 of those bites led to a hospital stay.3Poison Control. How dangerous is a black widow spider bite? Europe looks different: about 1 in 75 recorded widow bite cases ended in death, mostly from heart complications.4PubMed. Latrodectism in Europe (1973-2025): A systematic review of clinical manifestations, management and outcomes Those figures come from published case reports, which tend to capture the most serious cases.
A bad black widow bite is still unlikely to kill. The venom acts on nerves, so pain and cramping can spread from the bite to the belly, back or chest. Symptoms usually peak within the first several hours and ease over a day or two, though some soreness can linger. Healthy adults generally recover with pain relief and observation. Hospital care matters most for those at higher risk: young children, older adults, pregnant women and people with heart disease or high blood pressure.
Part of the reason for the low toll is that a bite does not always deliver venom. Spiders use venom to catch prey, and when they bite something as large as a person in defense, they often hold it back. Even when venom goes in, the amount varies a lot, so two people bitten by the same kind of spider can have very different symptoms. Many bites that leave a bit of redness, a sting or a small bump come from spiders whose venom is not medically important to people at all.
Australia’s dangerous spiders stopped killing once treatment arrived. The last recorded spider bite death there was from a Sydney funnel-web spider in 1979.5CPR First Aid. How Many People Die From Spider Bites In Perth And Australia? Thirteen funnel-web deaths were recorded before antivenom, and seven of them were children.6Medical Journal of Australia. Funnel-web spider bite: a systematic review of recorded clinical cases Since antivenom was introduced around 1980, no confirmed deaths have followed.7Medical Journal of Australia. Funnel-web spider bite: a systematic review of recorded clinical cases
Spiders also account for a small share of deaths from venomous animals. In older California records, bees, wasps and ants caused 56% of those deaths and snakes 35%.8PubMed Central. Deaths from bites and stings of venomous animals Spiders caused only 6%.9PubMed Central. Deaths from bites and stings of venomous animals
Where In The World Spider Bites Are Deadlier
Brazil shows how location changes risk. The country records more than 145,000 bites and stings from insects, spiders and scorpions every year, with about 145 deaths.10PubMed. Epidemiology of arthropods envenomation in Brazil: a public health issue More than 60% of those deaths are from scorpions, not spiders.11PubMed. Epidemiology of arthropods envenomation in Brazil: a public health issue Among spider bites specifically, the far-northern Amazon state of Roraima saw about 1 in 130 prove fatal.12PubMed Central. An overview of spider accidents in the Brazilian Amazon In Brazil’s non-Amazon states, the rate was about 1 in 2,500.13PubMed Central. An overview of spider accidents in the Brazilian Amazon Distance from hospitals and antivenom seems to matter as much as the spider.
Wandering spiders, among Brazil’s best-known biters, are rarely serious. About 9 in 10 people they bit had only mild symptoms such as pain.14PubMed. A clinico-epidemiological study of bites by spiders of the genus Phoneutria Only about 1 in 200 bites became severe, and those cases were in young children.15PubMed. A clinico-epidemiological study of bites by spiders of the genus Phoneutria
If you’re traveling to Brazil or Australia, shake out shoes, boots and clothes left on the floor before putting them on, and wear gloves when moving firewood, debris or stored boxes. In remote areas, find out beforehand how far the nearest hospital is.
Why Young Children Face The Greatest Risk
When a widow or recluse bite does turn deadly, it is rare, and it is most often in small children.16Mayo Clinic. Spider bites – Symptoms and causes In a child’s smaller body, the same amount of venom is more concentrated, so it can hit harder.17Pediatric Emergency Medicine Reports. Envenomations in Children Children are also much more likely to develop the whole-body reaction to a brown recluse bite.18PLoS ONE. Children at greater risk for complications from brown recluse spider bites In Brazil, wandering spider bites pose the most risk to children under 10 and adults over 70.19PubMed. A clinico-epidemiological study of bites by spiders of the genus Phoneutria
A child who can’t explain what hurts may show it in other ways. Unusual fussiness, inconsolable crying or pain that doesn’t let up can be the first sign. Vomiting, heavy sweating or stiff, cramping muscles suggest the venom is affecting more than the bite spot and deserve prompt medical attention. Trouble breathing is an emergency, so call emergency services right away rather than waiting. In the US, Poison Control at 1-800-222-1222 is free, open at all hours, and can tell a parent whether to watch at home or go to a hospital.
Clear clutter in garages, sheds and closets, where widows and recluses hide. Move beds away from walls and keep bedding off the floor. Check toys and shoes stored outdoors before a child uses them.
Symptoms That Mean You Should Get Help And How Treatment Works
Brown recluse bites usually stay on the skin. The venom can cause a slow-healing open sore that may take months to heal.20PubMed Central. Fatal Viscerocutaneous Brown Recluse Envenomation With Orbital Compartment Syndrome Much more rarely, it destroys red blood cells, harms the kidneys and blocks normal clotting.21PubMed. Emergency department death from systemic loxoscelism These whole-body effects usually show up within 24 to 48 hours of the bite.22PubMed Central. Fatal Viscerocutaneous Brown Recluse Envenomation With Orbital Compartment Syndrome So dark urine, fever or severe weakness in the first two days needs urgent care.
Antivenom is a medicine made to block a spider’s venom, and its value depends on the spider. Funnel-web antivenom fully reversed symptoms in 97% of confirmed bites, and severe allergic reactions to it were uncommon.23Medical Journal of Australia. Funnel-web spider bite: a systematic review of recorded clinical cases24PubMed. Funnel-web spider bite: a systematic review of recorded clinical cases For Australian redback bites, though, adding antivenom to pain medicine did not clearly improve pain.25PubMed. Randomized controlled trial of intravenous antivenom versus placebo for latrodectism: the second Redback Antivenom Evaluation (RAVE-II) study In one California group, black widow antivenom relieved pain for every patient, with only minor side effects.26PubMed. Examination of adverse events following black widow antivenom use in California
In the first minutes after a bite, wash it with soap and water, which lowers the chance of infection, a more common problem than venom. Apply a cold pack wrapped in cloth for short periods to ease pain and swelling. In Australia, a suspected funnel-web bite calls for a firm bandage over the bite and limb, keeping the person still, and calling emergency services right away.
At the hospital, the main work for most bites is controlling pain and watching for symptoms that spread beyond the bite. After a suspected recluse bite, blood and urine tests can check for red blood cell damage and kidney trouble. Antivenom is saved for serious cases, such as a funnel-web bite with body-wide symptoms. Most people go home after a period of observation once symptoms are under control.
Many Spider Bites Are Not Spider Bites At All
Among emergency patients who thought they had a spider bite, fewer than 4% actually did.27PubMed. “Spider bite” lesions are usually diagnosed as skin and soft-tissue infections About 86% had a skin infection instead.28PubMed. “Spider bite” lesions are usually diagnosed as skin and soft-tissue infections A common culprit is MRSA, a staph infection that resists common antibiotics and is often mistaken for a spider bite.29PubMed. It’s Not a Spider Bite, It’s Community-Acquired Methicillin-Resistant Staphylococcus aureus Brown recluses don’t even live in Canada, yet Canadian sores are often blamed on them.30PubMed Central. An approach to spider bites. Erroneous attribution of dermonecrotic lesions to brown recluse or hobo spider bites in Canada
If an infection is blamed on a spider, it can go untreated while the person waits for a bite to heal, and it can spread. A drug-resistant staph infection may not respond to the usual first-choice antibiotic. A sore that is red, warm, swollen and growing, or that has pus, points to infection more than a spider bite. A doctor may drain it, prescribe an antibiotic that works against resistant staph, or both.
You can help a doctor sort out a mystery sore. Say plainly if you never saw a spider, since a guessed bite can push a doctor toward the wrong diagnosis. Mention when the sore appeared, how fast it has changed and whether anyone around you has had similar sores, which can suggest infection. Marking the edge of the redness with a pen shows whether it is spreading over hours.
Why Spider Bite News Feels Scarier Than The Numbers
In stories about Mediterranean recluse bites, fewer than 1 in 10 bites were from the spider named.31People and Nature. Media framing of spiders may exacerbate arachnophobic sentiments Two of three deaths reported were fake, and the third couldn’t be confirmed.32People and Nature. Media framing of spiders may exacerbate arachnophobic sentiments The exaggerated stories were also shared more on social media.33People and Nature. Media framing of spiders may exacerbate arachnophobic sentiments
To judge a scary spider story, check whether a doctor or spider expert confirmed the spider, because many stories rely on a guess by the patient or a reporter. Ask whether that spider lives in the area, since a recluse bite story far outside its range is likely wrong. Many sores called bites are infections, so a story that skips testing or diagnosis deserves doubt.
Some ranges may be shifting. Warming may push brown recluses into states such as Ohio, Pennsylvania and Michigan.34PubMed Central. Tracking a Medically Important Spider: Climate Change, Ecological Niche Modeling, and the Brown Recluse (Loxosceles reclusa) A venomous yellow sac spider is spreading north across Europe.35PubMed Central. Rapid genetic and ecological differentiation during the northern range expansion of the venomous yellow sac spider Cheiracanthium punctorium in Europe