Dupilumab Skin Barrier Function Study in Atopic Dermatitis

Inclusion criteria : \- Participant must be between 12 to 65 years of age (inclusive), at the time of signing the informed consent. Atopic dermatitis participants: * Male or female participants. * Participants with AD diagnosis according to Hanifin and Rajka criteria at least 1 year before screening. * Investigator Global Assessment score of \>=3 at screening (on the 0-4 scale). * Participants with moderate to severe atopic dermatitis that were eligible to be treated with dupilumab according to product monograph. * Participants with AD must have had active lesions on the upper limbs or lower limbs, with severity for lesion erythema or edema/papulation \>=2 at screening on the 0-3 scale of the individual signs score. * Patients must have had a non-lesional (normal looking) skin area 4 centimeters from the edge of the lesional area. * Were willing to refrain from applying any topical medication products on the target assessment areas (including lesional and non-lesional) throughout the study unless necessary to alleviate intolerable symptoms. * Were willing to refrain taking showers or soaking in a bathtub with soaps and body washes within 6 hours before TEWL assessments. * Were willing to apply Cetaphil or Vanicream moisturizer up to twice a day with an exception of moisturizer application on the targeted assessment areas (lesional and non-lesional areas) during the entire study from Day -7 to end of treatment. * Were willing and able to comply with all clinic visits and st…