Skin Flap, Full Thickness
In mountain biking, skin flaps are either the result of catching skin on a branch or
peeling the skin away during a fall.
A "full thickness" flap or avulsion is complete loss of all layer of the skin.
Even if the skin is still attached (a flap), full thickness injuries should be seen by the
|This full-thickness flap was (IMPROPERLY) snipped off by the patient a few
days ago. It's not healing well, because all layers of the skin were lost. The skin changes
shape when traction is put on it. Note the fatty tissue.
flap of skin was pulled away during a fall onto the outstretched hands.
In an older person with very thin skin, a FULL THICKNESS avulsion or flap can look very
thin. It can appear as thin as the top of a blister! If you're ever unsure whether a flap
is partial or full thickness, treat it as a FULL THICKNESS injury!
If there's a flap, leave it in place. Clean with Betadine. Put on a padded dressing. Go to
the doctor. See section on infection.
Skin Flap, Partial Thickness
Partial-thickness flaps are most likely to occur where the outer layer of the skin is very
thick, such as the palm or fingerpads. Usually, the cause is landing on the hands at a
high speed. This peels the skin back.
A "partial thickness" flap is loss of only the outer (epidermis) layer of the
skin. The skin will re-grow from underneath. The loose skin is dead. We can tell this is a
partial thickness injury because there are "fingerprint lines" on the underside.
Also, the skin doesn't change shape when traction is put on it. If you're ever unsure
whether an avulsion or flap is partial or full thickness, treat it as a FULL THICKNESS
Result of grabbing a gambel oak trunk with the
ungloved hand while careening out of control. Note the fingerprint lines.
You must be sure the flap is truly partial thickness before trimming it away. Old persons
have extremely thin skin -- you may be fooled into cutting off a full thickness flap! Even
physicians make this mistake. If you cut off a full thickness flap, it will take many
weeks to heal and will scar badly. Partial thickness flaps may have debris under them. If
so, it must be trimmed away. Even with cleaning, there's a great risk of infection if the
See the doctor if:
you're unsure of the injury's depth
you can't clean away the contamination
the avulsion involves a large area
the avulsion is larger than a thumbprint on the hand
the avulsion is in a critical area (face, genitals)
NOTE: Whether you replace the skin or snip it away depends on: COMFORT (leave it) versus
INFECTION (if there's dirt under the flap -- snip it). If the flap is absolutely clean
(and is in an area that may be bumped), you can replace the flap. Clean with Betadine.
Wipe away any blood from beneath the flap. Apply antibiotic ointment. Now plaster the flap
back into position. Apply a dressing that puts light pressure on the wound.
If there's dirt on (or under) the flap, you must remove the flap. Clean with Betadine.
Use small, clean scissors to snip away the flap. Apply an antibiotic ointment. Place a
non-stick pad, then roll a kling wrap around the wound. (You can substitute a manufactured
bandage such as a knuckle bandage if you're sure it will cover and compress well.)
Keep the wound clean, dry, and protected from chafing and bumping. Change the dressing
every day, or whenever it accidentally gets dirty. After two days, you can resume washing
(but always put a dry bandage on afterwards). When the wound looks like normal skin and
feels like normal skin you can stop bandaging. Expect about 7 to 14 days for healing.
See the doctor if there is redness around the wound, red streaks, swelling, drainage,
fever, tender bumps in the groin or armpit upstream from the wound, or an unexplained
increase in pain or tenderness. See section on infection.
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