Skin Flap

Skin Flap, Full Thickness

Scenario:
In mountain biking, skin flaps are either the result of catching skin on a branch or peeling the skin away during a fall.

Description:
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 doctor. In an older adult with thin skin, it can be difficult for a layman to see the difference between "blister thickness" and "all layers of skin." Best to get medical attention if you're not very very sure.

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. This was not a superficial blister-like flat of epidermal skin. It was the entire epidermis and dermis.
Semicircular flap of skin was pulled away during a fall onto the outstretched hands.
Semicircular flap of skin was pulled away during a fall onto the outstretched hands.

Caution:
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!

Immediate care:
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

Scenario:
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.

Description:
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 injury!
Result of grabbing a gambel oak trunk with the ungloved hand while careening out of control. Note the fingerprint lines.
Result of grabbing a gambel oak trunk with the ungloved hand while careening out of control. Note the fingerprint lines.

Concerns:
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 flap remains.

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)

Immediate care:
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.
Removing the dead skin because the underside is contaminated with debris.
Removing the dead skin because the underside is contaminated with debris.

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.)

Ongoing care:
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.

Watch for:
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.