According to PetMD, mange in cats manifests itself as small hairless patches on the head, particularly around the eyelids, as well as hair loss on the neck and flank. The bare patches of skin may display scaling, red lesions and crusty scabs.
MangeCure.info states that mange is caused by mites, which are tiny arthropods that live off blood. The site notes that although almost all mammals can get mange, the kind of mange specific mammals get infected with differs. While dogs primarily get demodectic mange, cats are most frequently infected with notoedric mange, which is also known as "feline scabies."
In feline scabies, mites burrow under the skin, causing intense itchiness that is so difficult to relieve that infected cats typically injure themselves. This produces the characteristic scabbing and hair loss. The ASPCA describes the early stages of the infection as producing restlessness and frequent scratching behavior, particularly around the face and head. Although most infections are on the face and head, feline scabies can spread to the rest of the body.
LoveToKnow Cats adds that infected cats may display other signs of skin irritation, such as ear discharge and brown marks on the nose and ears, as well as symptoms of general illness, such as weight loss, loss of appetite and dehydration.