Thick crusts
Severe scabies can cause crusts to form on this skin. This type of scabies is called Norwegian scabies [6]. In people with this condition, several thick crusts form on the skin and have hundreds to thousands of mites lodged within them. The symptoms of scabies are extremely bad in people with Norwegian scabies.
The people at the greatest risk of developing Norwegian scabies are immune-compromised individuals and elderly people. The associated crusts are often gray, thick, and crumbling [7]. The crusts can detach from the skin and harbor mites for more than a week, nourishing them with food within the crusts.