Treatment Visit (Day 28 +/- 7) Eligible subjects with + S. aureus screening cultures will be enrolled in the study and instructed to return to the clinic approximately 28 days after their screening visit. This 3-week waiting period will allow laboratory staff to grow and prepare the subject's endogenous AMP-producing bacteria to be mixed with Cetaphil for application at the treatment visit. AMP-producing bacteria will also be screened to ensure that it is not pathogenic. To simulate real-life scenarios as much as possible, the subject will be allowed to continue their usual activities during this study, including bathing, showering, and exercising. This visit will begin by reviewing the subject's interim medical history, including medication history to ensure that he/she did not use any topical AD treatments on their arms within 7 days or oral AD treatments within 28 days of this visit. For subjects who had a S. aureus (+) nasal culture at screening visit, a repeat nasal culture will be performed. For all subjects, a focused physical exam will then be performed of the subject's bilateral arms to ensure that there is no evidence of cracks, breaks or infections of the skin on the arms. The localized SCORAD and Eczema Severity Scale will be completed on each antecubital fossa. A TEWL meter will then be used to measure the TEWL of each antecubital fossa. Next we will pre-treat both arms with a regimen of washing with Dial liquid antibacterial soap, followed by wiping the arms with 70%, then 80% alcohol. Once the alcohol has dried, a thin coat of the subject's individualized AMT cream will then be applied to one arm by the gloved hands of a study coordinator, and Cetaphil lotion alone to the other arm. The two creams will be labeled as either 'Right' or 'Left' to allow the study to be conducted in a double-blind manner (both the subject and the clinical investigator/coordinator will be blinded as to which arm received which treatment). Five minutes later, a quantitative washing will be performed on eczematous skin of both antecubital fossae as well as on an area of non-lesional skin of both arms. For each wash, a sterile stainless steel cylinder with an approximate area of 3.5 cm2 will be held firmly to the skin surface, and 2.5 mL of a sterile stripping fluid (SSFN) will be carefully instilled into the cylinder. The skin will then be massaged for 60 seconds using a sterile rubber policeman. The SSFN will be aspirated with a pipette and transferred to a sterile test tube. This entire process will be repeated a second time and the fluid pooled together. The pooled fluid will be analyzed in the lab via colony counting methods to determine the amount of viable bacteria on the skin at this time point. Skin swabs of lesional and non-lesional skin of both arms will also be taken to determine what type and the abundance of each bacteria present on the skin. The subject will then receive single-use aliquots of his individualized AMT cream and Cetaphil lotion alone, as well as gloves, and instructed to apply one aliquot to its assigned arm at the dosing interval determined in Experiment 1 (but not to exceed TID). All aliquots will be labeled with either 'Left' or 'Right' depending on which arm they should be applied to based on whether the aliquot is of control Cetaphil lotion or the AMT cream. Since the two products are identical in appearance and consistency, subjects should not be able to distinguish between the two products. All subjects will be instructed to wash their hands and put on clean gloves before each aliquot application. This will conclude the treatment visit. We expect this visit to take approximately 60 minutes.