The Effects of Emollient Therapy on the Skin Barrier

The goal of this study is to better understand what effect emollients (moisturizers) have on the skin in young children and adults. Subjects will be recruited from PI and Sub-I clinics and Oregon Health \& Science University (OHSU) research opportunities website. 1. Adult and Adolescent Study: Moisturizer Intervention - There will be 2-3 visits for this study: a screening visit, a baseline visit, and a final visit. Adults with a history of eczema will be asked to apply one of four possible moisturizers to one arm and nothing to the other arm for four weeks. The moisturizers, which will be assigned to the subjects, include either Cetaphil Cream, Aveeno Eczema Therapy Moisturizing Cream, CeraVe Moisturizing Cream, or Vaseline 100% Petroleum Jelly. Subjects can use other skin treatments as needed for their skin condition, but may not treat the arms during the study. Non-invasive tests of the skin will be made at Visit 1 and after four weeks (Visit 2). The skin measurements that will be performed are: * Transepidermal loss (TEWL)- measures how much water is lost across the skin barrier * Skin Cohesion and TEWL - TEWL after 5, 10, 15, and 20 tape strips will measure skin barrier function after tape-stripping * Skin electrical capacitance - measures the moisture in the top layer of skin * Skin pH - measures the acidity of the skin * Stratum corneum cohesion assay - tape-stripping to measure the protein removed from the top layer of skin * Lipidomic analysis - measures the lipids, or oils, in the top layer of skin Control - There will be 1-2 visits for this group: a screening visit and baseline visit, which can be combined. Non-invasive tests of the skin will be taken and include the skin measurements that will be performed are the same as the Moisturizer Intervention group. 2. Pediatric Study: There will be 2-3 visits for this study: a screening visit, a baseline visit, and a final visit. Infants and toddlers between 3 months and 3 years of age wit