A deep tissue pressure injury is damage that starts underneath rather than at the surface. It’s a pressure sore that develops in the tissue deep below the skin.
What it looks like: the area may be dark purple or maroon, and there may be a blood-filled blister under the skin.
Here’s why it’s singled out: this type of skin injury can quickly become a stage III or IV pressure sore.
Quickly, and to the two stages that are harder to treat and slow to heal. That’s a different path from a stage I mark, and it’s why a dark purple or maroon patch is not something to watch for a few days.
Like an unstageable sore, it sits outside the four stages. Both are types that don’t fit into the staging system: one because a covering hides the depth, the other because the damage is below intact skin.
Where to look is the usual list, and the places people can’t see are the ones that matter: buttocks, elbow, hips, heels, ankles, shoulders, back, and the back of the head. Check your skin for pressure sores every day, and ask your caregiver or someone you trust to check areas you can’t see.
A purple or maroon area on a heel or a tailbone, on someone who spends long periods in a bed or a chair, is exactly what to look out for.