We're all familiar with abrasions. If you don't get scraped up, you aren't really mountain biking. Most biking abrasions involve knees, back of the elbows and upper forearm, and shoulders.
An abrasion is a scrape. It's caused by a rubbing injury that strips off the outer layers of skin. Large and deep abrasions are more serious. (If the injury changes shape significantly when pulling on the skin, or it fat tissue is seen, this is NOT an abrasion -- it's a full-thickness avulsion, a complete loss of all layers of the skin.)
Any deep abrasion will leave some scar tissue behind. On the face, scars are unsightly. Over joints, a bad scar may prevent full motion. Proper treatment will minimize the scar, making it less noticeable and reducing stiffness. An abrasion is often contaminated with dirt, gravel, and other foreign material. Infection is a risk, especially with deep, crushed, or dirty abrasions. In some severe abrasions, the skin will die -- leaving the equivalent of a third-degree burn.
An abrasion should hold its shape when the skin is moved or stretched. If any part of the wound gapes or changes shape, this is a more serious injury.
See the doctor if:
there is mushy tissue exposed that changes shape easily
the scrape is extremely dirty or won't come clean
the scrape is very large
the scrape is on a critical area: face, genitals, hands
Relieve pain with an anesthetic spray or pain relieving gel. Wash the scrape thoroughly. If necessary, soak in the tub. The quicker you start scrubbing the abrasion, the less it will hurt. Be aggressive. Use a plastic pot-scrubbing mesh if necessary.
After the initial washing, scrub with Betadine, Bactine, or another antiseptic on a gauze pad. If you can't get the abrasion clean, go see the doctor.
Bandage the abrasion. Usually, a non-stick pad, then gauze, then a kling wrap protects a larger scrape well. A self-adhesive wrap, such as Coban, helps hold everything in place. The wrap should be wide enough, and snug enough, that it doesn't slip around. But it shouldn't be "tight." If it feels uncomfortable, loosen it up.
Change the dressing daily. If the bandage sticks, soak it in warm water with a drop of soap. Dilute hydrogen peroxide can help soften a thickly crusted bandage. The scrape will heal much more quickly if it's bandaged for the first few days.
See the doctor if there is redness around the wound, red streaks, swelling, drainage, fever, tender bumps in the groin or armpit upsteam from the wound, or an unexplained increase in pain or tenderness. See section on infection.