Erosions are shallow defects in the skin that only affect the skin's upper layers. Erosions can be quite painful, but tend to heal quickly if the skin is protected and the underlying cause is eliminated.
Signs include partial or total hair loss. The skin surrounding the area of hair loss can appear normal or it can have redness, bumps, scabs, and skin loss. Alopecia may appear in a symmetrical form, or it can be random on the cat's skin.