Comparison of Cathelicidin Expression in Skin and Saliva in Patients With Atopic Dermatitis and 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.