Are White Spiders Poisonous & What to Do If You’re Bitten

White spiders found in gardens, windowsills, and flower beds are overwhelmingly harmless to people. Nearly all spiders produce venom, but the white-colored species you are most likely to encounter lack the potency to cause anything beyond brief, mild discomfort in a healthy adult. The distinction between “poisonous” and “venomous” matters here, too, and it is one many searchers get wrong. Beyond that, a surprising amount of what people believe about white spider bites, especially the idea that they cause festering wounds, has been thoroughly debunked by clinical research.

Which Spiders Are Actually White

Several spider species appear white or very pale, and the ones you are most likely to see depend on where you live. The most common globally is the goldenrod crab spider (Misumena vatia), a stocky, slow-moving ambush predator that sits inside flowers waiting for pollinators. Crab spiders can shift between white and yellow over the course of days to match the flower they are hunting on. The color change involves a set of pigment molecules called ommochromes: white individuals have high levels of certain precursor compounds, while yellow individuals accumulate different pigments in their outer tissue.¹ These spiders have no interest in biting humans and their fangs are too small to penetrate skin in most cases.

In Australia, the term “white spider” almost always refers to the white-tailed spider (Lampona cylindrata and Lampona murina). These are dark-bodied hunting spiders with a distinctive white or cream-colored spot on the tip of their abdomen. They often wander indoors at night. Despite a fearsome reputation online, the clinical evidence on their bites tells a very different story, which we will get to shortly.

Other pale or white spiders you might encounter include certain species of running crab spiders, ghost spiders (Anyphaenidae), and some orb weavers. Pale yellow sac spiders (Cheiracanthium species) are sometimes mistaken for white spiders because their bodies range from cream to light green. These are among the few “whitish” spiders that have a noticeable bite, though even they are medically mild.

Venomous vs. Poisonous

Almost every article on spider safety has to make this correction, so let’s get it out of the way: spiders are venomous, not poisonous. Venom is injected, typically through fangs. Poison is ingested or absorbed through touch. You could, in theory, swallow spider venom without ill effect because your digestive system would break it down. The distinction is not pedantic. It tells you that the risk from a white spider comes specifically from a bite, and that simply handling one or finding one on your skin is not dangerous. Most white spiders you will encounter are reluctant biters in the first place, since their venom is designed for subduing insects, not defending against something thousands of times their size.

What Happens When a White Spider Bites You

The most well-studied white spider bites come from the Australian white-tailed spider, and the findings are reassuringly boring. A prospective study tracked 130 confirmed Lampona bites and found that the typical result was localized pain and a red mark. About half of the patients developed a persistent painful red lesion, but there were no cases of tissue death or confirmed infections.² A separate review noted that more than 135 confirmed white-tailed spider bites have now been documented in the medical literature, with no evidence of skin necrosis in any of them.³

For yellow sac spiders, which are sometimes light enough to be called white, the bite can be more immediately painful. Their venom has some ability to damage cells and break down membranes locally. A case series from Slovenia found that bites from Cheiracanthium punctorium were often very painful and sometimes came with temporary neurotoxic effects, but all patients recovered completely with no lasting damage.⁴ A larger review of 20 verified Cheiracanthium bites in the United States and Australia found no necrosis in any case.⁵

Crab spiders, ghost spiders, and most other white species rarely bite people at all, and when they do the result is comparable to a mild bee sting or less. The fangs of many small white spiders cannot reliably break human skin.

The Skin-Rotting Myth

If you have ever searched online for white spider bites, you have probably seen alarming photos of open, necrotic wounds attributed to spider bites. This idea, sometimes called “necrotic arachnidism,” has been attached to white-tailed spiders in Australia and yellow sac spiders in North America for decades. The clinical evidence does not support it.

The white-tailed spider myth is especially persistent. Despite the growing body of published bite cases showing no skin ulceration, internet forums and even some older medical references continue to blame Lampona for necrotic wounds.³ The same pattern holds for yellow sac spiders: medical textbooks and review articles have repeated the necrosis claim for years, yet among dozens of verified bites across multiple countries, only one case of mild necrosis has ever been documented, and that was in a European species.⁵

So where do those horrific wound photos come from? In most cases, the real culprit is something entirely unrelated to spiders. A study examining patients referred with suspected white-tailed spider bites and necrotic ulcers found that every single case turned out to have a different diagnosis upon proper investigation. The actual causes included fungal infections, staph infections, an autoimmune skin condition called pyoderma gangrenosum, and even an infected diabetic ulcer.⁶ The researchers concluded that all ulcers blamed on spider bites should be properly investigated with bacterial and fungal cultures and a skin biopsy, because the spider explanation is almost always wrong.

When “Spider Bite” Means Something Else Entirely

The misdiagnosis problem extends far beyond white-tailed spiders. Across emergency rooms worldwide, skin lesions are frequently diagnosed as spider bites based on nothing more than a guess. The patient wakes up with a painful red bump, assumes a spider did it, and the treating clinician goes along with the story. In reality, bacterial infections are one of the most commonly misattributed causes. Methicillin-resistant Staphylococcus aureus (MRSA) skin abscesses are particularly notorious for being mistaken for spider bites.⁷ The early stages of a MRSA boil, a developing fungal infection, or even a herpes outbreak can all look like something a spider might have done.

This matters because a misdiagnosis delays the correct treatment. If you have a skin wound that is growing, becoming more painful over days, producing pus, or developing black or purple edges, the most useful thing you can do is see a doctor who will culture the wound and test for bacteria or fungi. Insisting it was a spider bite can lead to antibiotic-free watchful waiting when you actually need targeted treatment. The spider, to put it bluntly, is almost always innocent.

What to Do If You Are Bitten

If you see a white spider bite you and want to know what to do next, the honest answer is that most bites need nothing more than basic wound care. Here is what that looks like:

• Clean the site: Wash the bite area with soap and water as soon as you can. This is the single most useful step because it removes bacteria from the skin surface.
• Apply a cold pack: A wrapped ice pack or cold compress held on the bite for 10 to 15 minutes reduces swelling and numbs pain.
• Take a pain reliever: Over-the-counter options like ibuprofen or acetaminophen are enough for the mild pain most white spider bites cause.
• Watch for changes: Over the next day or two, keep an eye on the bite. A little redness and soreness is normal and should fade. Spreading redness, warmth radiating outward from the bite, swelling that worsens rather than improves, or any sign of pus or fever is a reason to see a doctor.

There is one practical addition to this: if you can safely capture or photograph the spider, it helps. Many bites are never confirmed because the spider is not identified. Having a photo allows a healthcare provider or entomologist to determine whether the spider is medically relevant at all, which in most cases it is not.

When You Should Get Medical Help

The vast majority of white spider bites resolve on their own. But there are situations where you should not wait. Seek medical attention if you develop any of the following after a bite:

• Spreading redness or red streaks: This can signal a secondary bacterial infection, not venom toxicity.
• Fever or chills: Systemic symptoms suggest the bite introduced bacteria or that you are having an unusual reaction.
• Muscle cramps or widespread pain: While not typical of white spider bites, some pale spiders are misidentified, and widespread muscle pain could indicate a bite from a more medically significant species.
• A wound that worsens after 48 hours: Normal spider bites improve steadily. A lesion that keeps growing after two days is probably not a simple bite and needs investigation.

One underappreciated reason to see a doctor is bacterial contamination of the bite itself. Research has shown that synanthropic spiders (the ones that live alongside humans in homes and sheds) can carry a range of pathogenic bacteria on their fangs and body surfaces. In the noble false widow spider, for example, researchers isolated 11 species of potentially harmful bacteria from the spiders’ chelicerae and exoskeletons. Those bacteria could be introduced directly into the skin during a bite, and in some cases the venom’s ability to damage local skin cells may create conditions that help bacteria thrive.⁸ This does not mean every spider bite gets infected, but it does mean that cleaning the wound thoroughly is not just a formality.

Spiders You Should Actually Worry About

For context, the white spiders you find in your garden or home are not on the short list of medically significant spiders. That list is surprisingly brief. In North America, the two groups that can cause serious harm are widow spiders (Latrodectus species, whose venom targets the nervous system) and recluse spiders (Loxosceles species, whose venom genuinely can cause tissue necrosis). In Australia, the funnel-web and redback spiders carry the real medical risk. In South America, the Brazilian wandering spider and certain recluse species round out the dangerous roster.

None of these are white. Widows are black or brown with distinctive markings. Recluses are brown. Funnel-webs are dark. The color white, ironically, is one of the safer colors a spider can be from a human medical perspective. If you see a white spider, your odds of being seriously harmed are about as low as spider encounters get.

Why Our Fear of Spiders Outpaces the Actual Risk

Part of the reason people search for whether white spiders are dangerous is that spiders as a group trigger an outsized fear response. Research looking at emotional reactions to live arthropods found that spiders and scorpions provoked the highest fear scores of any group tested, significantly higher than insects, crabs, or beetles.⁹ Spiders also scored among the highest for disgust. These reactions are remarkably consistent across populations and seem to be at least partly innate rather than learned.

An unusual-looking spider, like a bright white one sitting in a flower, can amplify this reaction. Anything unfamiliar tends to be perceived as more threatening, so a white spider you have never seen before feels more dangerous than the ordinary brown house spider you see every week, even though neither one can hurt you. The fear is doing the threat assessment, not the evidence. Online image searches reinforce this: searching for any spider species plus the word “bite” returns a mixture of actual spider bite photos and unrelated wound images that have been incorrectly attributed to that spider. After scrolling through enough of those, anyone would feel concerned.

The mismatch between fear and actual risk is worth sitting with. People bitten by spiders frequently catastrophize the event because of deeply ingrained anxiety about spiders, and that anxiety drives them to emergency rooms where clinicians may validate the fear by diagnosing a “spider bite” without confirming identification. The result is a self-reinforcing cycle: the more people blame spiders for wounds, the more fearsome spiders seem, and the more willing the next clinician is to accept the spider-bite diagnosis. Breaking that cycle starts with recognizing that most white spiders are about as threatening as a ladybug with better PR.

Keeping White Spiders Out of Your Home

If you would rather not share your living space with white spiders regardless of how harmless they are, the approach is the same as for any indoor spider. Seal gaps around windows, doors, and utility openings. Remove clutter where spiders like to hide, especially in garages, closets, and under beds. Reduce outdoor lighting near doors and windows, because lights attract the insects spiders feed on, and the spiders follow the food. White-tailed spiders in particular come indoors to hunt other spiders, so reducing the general indoor spider population removes their incentive to enter.

Sticky traps placed along baseboards and in corners can catch wandering spiders and give you a sense of how many and what species you are dealing with. Chemical pesticides are generally unnecessary for spiders and often do more harm than good, since spiders eat pest insects and their presence usually means a healthy local ecosystem. If you find a crab spider in your garden, leaving it alone is the best option. It is there to eat aphids, mosquitoes, and other genuinely annoying creatures, and its contribution to natural pest control is far more significant than any risk it could ever pose to you.