Cathelicidins are small proteins in the human body that protect against infection. The purpose of this study is to determine if the amount of cathelicidins and other small proteins found in saliva can predict the amount of these in the skin of people who have acute atopic dermatitis (AD) or psoriasis.

People with AD or psoriasis are very sensitive to skin infections and inflammations. A group of small proteins known as cathelicidins are known to be responsible for immune defense against such infections. People with AD or psoriasis seem to be missing these proteins from their skin. The purpose of this study is to determine if the amount of cathelicidins and other small proteins in saliva is a predictor for the amount found in the skin. This is a single visit observational study. People with AD or psoriasis, as well as healthy participants, are being recruited for this study. Participants will provide a detailed medical history and undergo a physical examination. In addition, saliva and blood collection, and skin punch biopsies will be performed.