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Posted by Dr. Monica Wonnacott | June 15, 2020

How Do I Know if a Cut Needs Stitches?

One of the most common questions I get is, “Does this need stitches?” Here are a few tips that might help. (Note: When I say “stitches,” that simply means the wound needs closure by a doctor — see types of closures below).

 Wounds that need stitches are:

  1. Gaping open. If a wound is in a high tension area (think body areas that bend, pull, or move a lot) it is not likely to heal up on its own very well. Also, if the wound is quite deep, the edges will pull apart and need to be stitched closed.
  2. Deep. Wounds that involve just the top layer of skin don’t usually need stitches. If the cut is deep enough to be where the tissue changes color (the dermis) or you can see fat layers, muscle, or bone, you certainly will need stitches. Deep enough to need stitches is roughly 1/8 – 1/4 inch (2-4 mm) deep.
  3. Most wounds that are more than a ½ inch long, (1/4 inch for faces) will need to be stitched (unless it’s just a long stratch).
  4. Bleeding a lot. Typically, superficial wounds don’t bleed that much. It’s the deeper, more involved wounds that do. If you can’t get the cut to stop bleeding after a few minutes, you probably need medical care.
  5. Cosmetically tricky areas. Usually a wound that is professionally cleaned out and perfectly closed will heal with less scarring than a wound that is allowed to heal up on its own. So if scarring is a huge concern (say on a face), you may want to have a doctor address it.

Wounds that don’t need stitches:

  1. If the wound is a little deeper than a scratch, there’s no need for stitches.
  2. Puncture wounds. These injuries happen from accidents like stepping on a nail or a dog bite (with the canines). These wounds are really deep, but very small at the surface. The risk with these injuries is infections. Often these wounds will require medical care (e.g., a tetanus shot or antibiotics), but not stitches.
  3. Wide abrasions or scrapes. If the skin has been scraped off or injured so badly that there are no edges to sew together, you won’t need stitches. The biggest problem with these sorts of wounds is getting them properly cleaned out and preventing infection. Usually these sorts of wounds happen from bike crashes or bad trip and fall moments. These types of wounds might get lots of dirt, rocks, and road (road rash) in them, but there’s nothing to stitch.

Kinds of closures:

  1. Sutures. These are traditional stitches. Now there are lots of different materials designed for different circumstances (e.g., fine, thin stitches for faces and big, thick hardy stitches for knees).
    1. Absorbable (dissolvable): These are used when cuts are so deep that they need a layer on the inside. The body breaks them down and they don’t have to be removed.
    2. Non-absorbable (not dissolvable): These are used on the outside/top layer of the skin. They have to be cut and taken out.
  2. Staples. This method of closure uses a staple gun (not unlike a stapler you’d have in your office). The materials are a bit different though (designed for skin). It is quick and easy for a doctor to use. Ideal for use where scarring isn’t such a big deal and won’t be seen (e.g., will be used on a child’s head, covered by the hair). It requires a special device/remover to get them out (it bends the staple in half and the edges pull up and out).
  3. Glue. Imagine sterile super glue designed for skin and you’ve got the right idea. Glue can be wonderful (since you don’t have to numb the area first to fix it), but it has a lot of limitations. It can only be used in areas where there isn’t tension (otherwise it pulls apart easily) and the wound is a clean line. It also won’t work for big, deep cuts (it simply isn’t strong enough).
  4. Steri-strips. These can be used independently (in relatively small, shallow wounds) or as an added layer of strength to help hold another type of closure together. Steri strips are kind of like an extra strong, sterile piece of tape.

How long can I wait to get stitches?

The general rule of thumb is 6 hours (especially if it was a dirty wound). The worry about waiting a long time is risk of infection. Additionally, the wound starts healing in a different way when open for a long time. When a big, deep cut doesn’t get sewn up, it will eventually heal from the inside up (called secondary intention). This sort of healing has more risk of infection and scarring. Some wounds (especially if well cleaned), will still qualify for stitches up to 24 hours after the injury. The rule of thumb is close wounds as soon as possible. If circumstances prevented an immediate closure, see your doctor to see what your options are.

What if it the wound reopens?

This gets tricky. Depending on the location and what it looks like, sometimes they qualify for re-closure. If the cut is on the face, it is more likely to get re-glued or re-stitched. If it’s on the body, it depends on how long (48 hours is often the cut off) and how involved the wound is. Either way, it is a good idea to talk to your doctor in this circumstance.