How deep should a puncture wound be before you start worrying about it? (answer not needed fast)

To be honest, the impetus for this came because I stepped on… something… this morning on our kitchen floor. I’m not even sure what it was; it looked to me like nothing so much as a broken-off piece of a fruit pit (which, WTF, because we haven’t eaten pitted fruit in some time, but I dunno, it could have been something else – the Little One leaves all kinds of food on the floor in her wake, and I’m not always the best at cleaning up after it). Anyway, it was my heel and the whole weight of my body was on it, and when I looked at my sole I realized it had broken the skin, and I was able to squeeze a drop of blood out.

I’m not too worried about it. I think it was not at all deep, and I cleaned it off with alcohol and neosporin and I’m sure it will be just fine.

But because I have definite hypochondriac tendencies, that started me getting curious, because obviously I’ve heard of people losing their legs from blood poisoning after stepping on a nail and so on. How deep does a puncture wound, or a wound breaking the skin in general, need to be before you start worrying about that kind of thing, calling the doctor, getting tetanus shots, or whatever? Because obviously on one hand you have the paper cuts that break the skin but which no one ever worries about (I’m lucky if I remember to wash my hands after getting a paper cut on them), and on the other you have a nail going an inch into your foot which is clearly something where you need to get it looked at. So where should the line be drawn?

Generally speaking, any cut in the skin can introduce infection. Something like a paper cut closes quickly, and isn’t dangerous. Something like a nail in your foot won’t heal for a while, and even a very long time, without stitches. Doctors can clean and irrigate a wound, but when it’s something like a nail or knife going in and out, there’s not going to be much debris left.
So to answer your question, the line is whether or not a wound will heal reasonably quickly on its own. If you’ve potentially damaged interior things like nerves or blood vessels, then obviously that’s worth a check as well.

I see. That’s exactly the kind of thing I wanted to know. Thank you!

If it’s metal and it punctured skin, you could technically get tetanus. I keep my tetanus shot up to date when I go to my doctor normally so I don’t have to worry about that.

Metal doesn’t cause tetanus. Rusty metal has an association with tetanus because it’s a good breeding ground for the bacteria responsible, and metal is an easy way to get the deep puncture wounds that facilitate an infection.

A good way* to determine if a wound is deep enough to require medical attention is with a yardstick. No, I’m not joking about a 3 foot deep wound. Use the yardstick to measure the distance blood is spurting out of the wound. At 3 feet, you’ll probably pass out and die. At 2 feet you had a good chance of surviving except you wasted time finding a yardstick and measuring, so you’re probably going to die. 1 foot or less, stop the bleeding and get medical attention. If blood is spurting at all, as opposed to just dripping out of a wound, it’s pretty bad and a good idea to get it looked at even you have a good chance of surviving.

  • not actually a good way

The trouble with punctures is that you can get anaerobic bacteria deep in the wound that aren’t easy to clean out. If you cleaned the puncture really well and it isn’t terribly deep, I wouldn’t worry too much about it beyond keeping it clean and keeping an eye on it. Here is some wound care advice.

I stepped on a nail a few years ago and it went about an inch into my foot, but didn’t cause any significant bleeding. I got a tetanus shot because mine was out of date, but that was the only medical attention I received. Absent major bleeding that obviously needs stitches, I’m not going to the doctor for a wound. Haven’t died or had an infection yet. :slight_smile:

I’d say this is the main concern. It makes sense to me to get a tetanus shot if yours aren’t up to date, both as a precaution for this incident and as a preventive for the next ten years.

Tetanus is caused by a bacteria, not by metal. A thorn penetrating with bacteria on it could cause tetanus. Always good to have the shots up to date regardless.

IF you’re a diabetic or you have peripheral vascular disease or neuropathy or decreased sensitivity in your feet or you’re immunocompromised, then any cut deep enough to draw blood on your foot should be examined by a doctor and thereafter monitored closely for infection or nonhealing.

Assuming you’re none of those, it’s kind of a judgement call. You may need a butterfly bandage, steri-strips, glue or stitches* if there’s a flap of skin or incision type cut where the edges don’t stay together on their own after 10 minutes or so.

Puncture wounds tend to be more of a problem because the edges DO stay together, and that creates the oxygen free environment that tetanus and botulism love. This is just a generalization off the top of my head, and I reserve the right to be wrong, but I think I’d take any puncture wound larger than a pencil eraser, either in depth or width, to a medical professional. Something smaller (and assuming the person doesn’t have any of the medical conditions in my first paragraph), I’d run water over it for 5-10 minutes to clean it out very well, and use triple antibiotic and a nonstick bandage. Then I’d watch it carefully as it healed and take any signs of infection like redness, swelling and especially streaks of red to the ER toot suite.

Whatever the type of wound, seek medical attention if the bleeding doesn’t stop with constant (and I mean CONSTANT!) pressure for 10-15 minutes. If there’s something embedded in there, do *not *remove it - go to an ER and let them do it. You could be plugging up a severed blood vessel with the foreign body, and best to remove it and gush blood where there’s a suture kit handy.

*It depends on what you’ve actually done to yourself, but you may not need literal stitches, but another form of “stick your skin together”. There’s at least one orthopedic surgeon here in Chicago that uses NO sutures or staples for his spinal fusion surgeries…just steri-strips and maybe glue. This is after he’s cut through skin, muscle and BONE! So don’t let the fear of stitches or needles keep you from getting a serious cut looked at. Chances are good that they can use some other technique, if you don’t want stitches.