What's the difference between scab and crust? Can hair grafts come off when there are crusts?

A scab is basically clotted blood on top of your skin. A crust is the yummy part at the edge of your pizza.  A crust is a description of a hard outer layer.  So a scab can be described as a crust.

A scab is a layer that forms over a wound or cut. A crust is a hard layer that forms over a surface.Each hair transplant recipient site incision will form a scab. Depending on the amount of blood or tissue fluid that oozes from the incisions, the scabs may coalesce to form areas of crusting.Often the crusting cracks after a few days forming fissures that can be of concern for patients if they have not been pre-warned that this is normal.When the scabs and crusts fall off, the transplanted hair shafts may also shed.If this occurs after one week it should not affect the final transplant results.If you have concerns after a hair transplant you should always contact the doctor who performed your surgery.

These terms are used interchangeably. The crusts form on wounds and is part of the healing process above the skin. If they are washed off immediately after surgery and not allowed to form as we do in our patients, there is no impact on healing; however if they are pulled off before they are ready to be normally shed by the body, then the grafts, which are almost always attached to the underside of the crusts, will be pulled out. We wrote a paper on this about 13 years ago, studying what happens when crusts are pulled out. We looked the what looked like grafts attached to the crusts and sent them off to a hospital labs (over 100 patients were tested) and the lab confirmed that the grafts were in-fact pulled out.