Common House Spider Bite: Symptoms & Treatment (2026)
Most people who blame a bump on a house spider never actually see one bite them, and that's the point: common house spiders almost never bite, and when they do, the bite is mild enough to go unnoticed. If you're staring at a red mark and a spider in the corner of the room, here's what actually separates a house spider bite from something that needs more attention.
What the common house spider bite looks like
Bites are rarely felt as they happen. Common house spiders (Parasteatoda tepidariorum) have small fangs and mild venom, so most people only notice a mark hours later — if they notice it at all. When a bite does register, it's usually described as a faint pinprick rather than sharp pain, which is one reason so few bites are ever confirmed.
What you'll typically see is a small, slightly raised red bump, often no bigger than a mosquito bite, with mild surrounding redness. There's no reliable "signature" mark — no double puncture, no bullseye ring, no blister in most cases. Some mild itching and tenderness at the site is normal in the first day.
Because the mark is so nondescript, if you want to confirm what actually bit you, the BugKnow app can identify a common house spider from a phone photo in seconds, which is often more useful than trying to match the bite mark alone.
Misidentification runs both directions. People blame house spiders for bites actually caused by fleas, bed bugs, or mosquitoes, and they also mistake bites from more concerning spiders — like a brown recluse or black widow — for a "harmless house spider bite" simply because a house spider happened to be nearby.
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For an authentic common house spider bite, the majority-outcome fact is straightforward: most bites resolve on their own within a few days to about a week, with nothing more than local redness and itching. There's no confirmed evidence that house spider venom causes tissue damage or systemic illness in humans.
The signature complication people worry about — a spreading, blackened, non-healing wound — is almost never caused by this species. When that kind of wound does occur near a spot someone recalls being bitten, it's more often a secondary bacterial infection or the work of a different spider entirely, and that risk, while real, is uncommon.
Children, older adults, and people who are immunocompromised are somewhat more likely to develop a secondary infection at any minor wound site, including a spider bite, simply because their skin heals more slowly and their immune response is less robust. That's a wound-care risk, not a house-spider-venom risk specifically.
Bottom line: monitor a bite for the first 48 hours. If it's shrinking and less itchy each day, you're on the expected track. If it's spreading, darkening, forming an open sore, or accompanied by fever, treat it as an escalation trigger rather than something to wait out.
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Hours 0–2. A faint pinprick sensation or nothing at all. A small red mark may already be visible, with mild itching starting to develop.
Hours 2–8. Redness and mild swelling typically peak in this window. Itching is usually the most noticeable symptom; sharp or spreading pain is not typical for this species.
Day 1–2. Most bites are already fading by day two — less redness, less itch, no new symptoms. This is the window where a genuinely mild bite starts visibly improving.
Day 3–7. By this point the mark should be flat, pale, and no longer itchy for most people. If the bite is still worsening, spreading, or forming an open sore at day 3-7, that pattern doesn't match a typical house spider bite, and it's worth seeking medical care to rule out infection or a different spider.
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For a deeper visual reference, insectio.com's common house spider identification guide breaks down markings most photos miss.
Treatment
Wash and elevate. Clean the bite with warm water and mild soap as soon as you notice it, then keep the area elevated if any swelling starts.
Cool, don't heat. A cool compress or ice pack wrapped in a cloth for 10-15 minutes at a time is the safer general-purpose choice for calming swelling and itch; there's no reason to apply heat to this type of bite.
OTC support. An oral antihistamine handles itching well, and a topical hydrocortisone cream or an over-the-counter pain reliever can ease mild soreness. If you want a fast reality-check on whether the mark matches this species at all, a home bug identifier comparison photo can help before you commit to a treatment plan.
Watch, don't wrap. Leave the area uncovered or loosely covered so you can monitor it, and trace the border of any redness with a pen. If it's spreading past that line, developing pus, or accompanied by fever, that's the trigger to escalate to medical care.
Prevention
Because bites almost always happen when a spider is trapped against skin, the most useful habit is checking bedding, shoes, and stored clothing before use, especially in fall when spiders move indoors seeking warmth. Reducing clutter in closets, garages, and basements removes the tight, undisturbed corners these spiders prefer for webbing.
Sealing gaps around doors, windows, and utility entry points limits how many spiders get inside in the first place, and regularly clearing webs and egg sacs keeps populations from re-establishing in the same spots. If you've spotted more than one in your home, a full inspection is warranted.
Wondering whether to head to urgent care?
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A short decision tree based on CDC and Mayo Clinic guidance.
1 / 3 Are you having difficulty breathing, chest tightness, or swelling of the face, lips, or throat?
2 / 3 Is the bite spreading into a dark, blistering, or ulcerated wound?
3 / 3 Has the redness or pain been getting steadily worse for more than 48 hours?
Take 30 seconds to check your bite now.
Check My SymptomsFrequently asked questions
Do common house spiders actually bite?
Common house spiders rarely bite people. They avoid confrontation and only bite when trapped against skin, such as when rolling onto one in bed. Most encounters end with the spider retreating rather than biting. When a bite does happen, it's often not felt in the moment, and many people never trace a red mark back to a spider bite at all. Confirmed bites are uncommon enough that many reported "spider bites" turn out to be something else entirely.
What does a common house spider bite look like?
A house spider bite usually looks like a small, slightly raised red bump, similar to a mosquito bite. There's typically no distinct pattern, no double puncture mark, and no surrounding halo. Mild swelling and itching are common, but blistering or ulceration is unusual. Because the mark is so nondescript, people often misattribute unrelated skin irritation, other insect bites, or early infections to a house spider.
Are common house spider bites dangerous?
No. House spider venom is considered mild and not medically significant to humans. The large majority of bites cause only brief local irritation that resolves within a few days without treatment. Serious reactions are not documented for this species. The bites that do turn dangerous are almost always caused by a look-alike spider, such as a black widow or brown recluse, being misidentified as a common house spider.
How long does a house spider bite take to heal?
Most house spider bites heal within a few days to about a week, following the general pattern described in Mayo Clinic's overview of spider bite symptoms: redness and itching peak early, then fade without scarring. If a bite is still growing, spreading, or forming an open sore after several days, it's more likely a secondary infection or a different insect entirely, and it's worth having it checked.
How can I tell a house spider bite from a hobo spider bite?
Both are often mixed up because the spiders look similar and both bites tend to be mild. Hobo spiders build funnel-shaped webs and have plain, unpatterned legs, while common house spiders build messy tangled webs and have banded legs. Bite-wise, neither typically leaves a distinct mark, and current research finds no strong evidence that either species causes tissue death in humans, despite the hobo spider's old reputation.
Can a house spider bite make you sick?
It's unlikely. House spider bites are not known to cause systemic illness such as fever, muscle cramps, or vomiting the way black widow or brown recluse bites sometimes can. If you develop those symptoms after a bite, the spider was probably misidentified, or the symptoms are coming from an unrelated infection or illness rather than the spider itself.
Should I catch or kill the spider after a bite?
If you can safely capture the spider without risking another bite, doing so can help a doctor confirm what actually bit you, since many reported spider bites turn out to be something else. Take a clear photo instead if catching it isn't practical. Never try to handle or provoke a spider you can't positively identify as harmless.
How do I keep house spiders from biting me again?
Reduce clutter where spiders like to hide, seal cracks and gaps around doors and windows, and shake out shoes, gloves, or stored bedding before use. Vacuuming webs and egg sacs regularly discourages them from settling back in. Because bites usually happen when a spider is trapped against skin, checking bedding and clothing is the single most effective habit for avoiding accidental contact.
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