A Black Widow Bit Me. What Actually Happens Next?
By IdentifyThese Editorial · · 3 min read
Widow bites are frightening in a way that is disproportionate to their usual outcome, and the internet does not help. The honest version is that they hurt a great deal, that they are treated routinely, and that deaths in the United States are extraordinarily rare.
This is a description of what typically happens, not medical advice. A suspected widow bite is a reason to call a doctor or poison control — in the US, 1-800-222-1222.
The timeline
| Time after the bite | What is typically reported |
|---|---|
| 0–10 minutes | A pinprick, sometimes barely noticed. Two small marks may or may not be visible |
| 10–60 minutes | Pain begins spreading from the site, often up the limb |
| 1–3 hours | Muscle cramping, most characteristically in the abdomen or back. Sweating, raised blood pressure |
| 3–12 hours | Peak symptoms. Restlessness, nausea, headache |
| 1–3 days | Gradual decline in symptoms with treatment |
| Up to a week | Residual aching, weakness, poor sleep |
Why it is not a wound problem
This is the part that surprises people. Widow venom is a neurotoxin, and the trouble it causes is systemic rather than local.
There is no expanding ulcer, no tissue death, no wound that needs debriding. The bite site itself often looks like almost nothing — which is why people sometimes do not connect the abdominal cramping to a spider at all, and are investigated for appendicitis or a kidney stone before anyone asks about spiders.
If you have a spreading, blackening, ulcerating wound, that is not a widow bite. It may be a bacterial infection, and it needs looking at for its own reasons.
What treatment usually involves
Most cases are managed with pain relief and observation. Strong analgesia and muscle relaxants handle the cramping; the patient is monitored and goes home.
Antivenom exists and is effective, but it is reserved rather than routine — kept for severe cases, very young or very old patients, pregnancy, and people with cardiovascular disease. It carries its own risk of allergic reaction, which is why it is not given by default.
How dangerous is it really
Deaths from widow bites in the United States are vanishingly rare — the last confirmed cases are decades apart, against thousands of bites reported to poison control every year. Nearly everyone who is bitten recovers fully.
That is not a reason to ignore one. It is a reason not to panic while you arrange to be seen.
Who should go straight in
- Children and elderly people
- Anyone pregnant
- Anyone with heart disease or high blood pressure
- Anyone with severe cramping, chest tightness, or difficulty breathing
- Anyone who is not sure
The identification question
You do not need to identify the spider to be treated. Hospitals treat symptoms.
If the animal is safely contained, bring it. Do not go back to look for it, and do not delay getting seen in order to find it. For what a widow looks like against the far commoner house spider, see the hourglass and what else to check.
What people get wrong about the two marks
Textbooks show two puncture marks. In practice they are frequently invisible, and their absence proves nothing either way — fang spacing on a widow is roughly a millimetre, and on skin that is not a mark most people can find.
Looking for punctures is a poor use of the time. The cramping pattern is far more informative than the bite site, and it is what a clinician will ask about.
Where they actually are
Widows build untidy, strong, three-dimensional tangle webs low down in undisturbed places — under garden furniture, in meter boxes, beneath decking, in the corner of a garage. They bite defensively when pressed against skin, most often when someone puts a hand into a space without looking.
Gloves when reaching into dark corners outdoors is the whole precaution, and it is a good one.
If you think you were bitten
- Most suspected spider bites are not spider bites. Studies of patients presenting with a “spider bite” repeatedly find that the large majority are bacterial skin infections — frequently MRSA — which need antibiotics rather than reassurance. A spreading, painful, pus-filled sore is far more likely to be an infection than a spider.
- Wash it, ice it, and watch it. Clean the area with soap and water, apply a cold pack, and keep an eye on it.
- Get medical care if the wound spreads or darkens, if you develop cramping, sweating, fever or severe abdominal pain, or if you are confident it was a widow or a recluse.
- Bring the spider only if it is already dead and to hand. Do not go looking for it. Doctors treat symptoms, not species.
In the US, the Poison Help line is 1-800-222-1222. This site is a reference, not medical advice.
Keep reading
- Black Widow or Common House Spider? Look UnderneathWidows and house spiders build the same messy web in the same dark corner. The red hourglass underneath is the whole test — plus three backup checks including the egg sac.
- Do Brown Recluses Live Where You Do? Probably NotBrown recluses live in a small part of the United States, and are absent from California, Florida, the Pacific Northwest and the northeast — despite constant reports.
- Do Brown Recluses Come Out During the Day?They are nocturnal, but that is not the useful answer. What matters is when and why they end up on an open floor, and which encounters actually lead to a bite.