Dermatitis is a general word for any type of inflammation of the skin. It is usually used until a specific diagnosis is reached. There are many causes of skin inflammation, including external irritants, burns, allergens, trauma, and infection (bacterial, viral, parasitic, or fungal).
The signs of dermatitis can include itching, scaling, abnormal redness, thickening of the skin, and hair loss. The usual progression of a skin disease involves an underlying trigger that causes boils, scabs, scales, or blisters.
Abnormal itching, called pruritus, occurs in many diseases and is often present because of secondary infections. As the inflammation progresses, crusting and scaling develop. If the problem reaches the deeper dermis, fluid discharge, pain, and sloughing of the skin may occur. Secondary bacterial and yeast infections commonly develop as a result of skin inflammation. If the dermatitis does not improve, early signs of inflammation (such as redness) become obscured by signs of chronic inflammation (thickening of the skin, color changes, scaling, fluid discharge). Often the skin becomes drier. If itching is not already a sign, it will often develop at this stage.
Resolving dermatitis requires that your veterinarian identify the underlying cause and treat secondary infections or other complications. A review of your cat's history and a physical examination can more precisely define the problem.
Last full review/revision July 2011 by Karen A. Moriello, DVM, DACVD; Thomas R. Klei, PhD; David Stiller, MS, PhD; Stephen D. White, DVM, DACVD; Michael W. Dryden, DVM, PhD; Carol S. Foil, DVM, MS, DACVD; Paul Gibbs, BVSc, PhD, FRCVS; John E. Lloyd, BS, PhD; Bernard Mignon, DVM, PhD, DEVPC; Wayne Rosenkrantz, DVM, DACVD; Patricia A. Talcott, MS, DVM, PhD, DABVT; Alice Villalobos, DVM, DPNAP; Patricia D. White, DVM, MS, DACVD