Scratching Validation Study

Inclusion Criteria: * Be aged 18 to 75 years, inclusive * Be willing and able to undergo a single night of actigraphy and video monitoring overnight in a laboratory * Be willing and able to provide informed consent * (patients only): Diagnosed with atopic dermatitis by a clinician, following the criteria listed in Table 1. * (patients only): IGA score ≥ 2. * (patients only): Willing and able to use only non-medicated topical therapy (i.e., bland emollient/moisturizer) for 7 days before the overnight visit. * Participants should be in bed a minimum of 4 hours Exclusion Criteria: * Any acute and/or unstable illness or medical complication which, in the opinion of a clinician, could compromise data collection and/or interpretation * Use of any over-the-counter, prescription, or recreational drugs that may induce sleep or pruritus within 24 hours prior to overnight monitoring * Use of any over-the-counter or prescription treatment (systemic, or topical) that could affect the course of atopic dermatitis during the study period. Key medications are listed below: * From 3 Months prior to overnight visit: Biological products that might have significantly affected the evaluation of atopic dermatitis condition (e.g., tumor necrosis factor inhibitors, antiimmunoglobulin IgE antibodies, anti-CD20 antibodies, anti-interleukin-4 receptor) * Has used systemic treatments that could affect AD within 30 days or 5 half- lives before the overnight visit. (i.e. retinoids, methotrexate, cyclosporine, hydroxycarbamide (hydroxyurea), azathioprine and systemic corticosteroids) * Phototherapy treatment, laser therapy, bleach baths, tanning booths or extended sun exposure that could affect disease severity or interfere with disease assessments within 30 days before the overnight visit. * Use within 21 days before the overnight visit: Topical corticosteroids that were classified as super-high potency (clobetasol propionate). * Use within 14 days before the overnight visit: any other topical phosphodiesterase 4 (PDE4) inhibitor; Tacrolimus and pimecrolimus cream and/or ointment; Topical corticosteroids that were classified as low, medium, or high potency (e.g., fluocinonide, triamcinolone acetonide, desonide, hydrocortisone). * From 7 days before the overnight visit: * antibiotics * antifungal or antivirus medications * Antihistamines/anti-allergics: diphenhydramine, chlorpheniramine maleate, hydroxyzine) * Topical phosphodiesterase 4 (PDE4) inhibitor * Topical calcineurin inhibitors (tacrolimus and pimecrolimus cream and/or ointment) * Topical corticosteroids that were classified as low, medium, or high potency (e.g., fluocinonide, triamcinolone acetonide, desonide, hydrocortisone) * Any other topical therapy with active ingredients to treat AD or with additives that could affect AD (e.g., hyaluronic acid, urea, ceramide or filaggrin degradation products). * Individuals clinically diagnosed with a sleep disorder who are NOT on a controlled treatment regime * An Epworth Sleepiness Scale score of ≥11, indicating daytime hypersomnolence * Previous diagnosis of a movement disorder, including but not limited to, restless legs syndrome, periodic limb movement disorder, Tourette's syndrome, tremor, or dystonia * Commercial driver's license and/or high-risk occupation that could be impacted by the occurrence of daytime sleepiness * Self-reported habitual sleep duration of \<6 hours per night on average * Shift worker, advanced/delayed circadian phase, and/or any other condition suggesting that the participant would be unable to sleep during overnight monitoring * Self-reported pregnancy current or planned during the study * Employee or spouse of an employee of company that designs, sells, or manufactures sleep related products and/or wearable devices (including Philips). * (patients only): Any significant dermatological condition, other than atopic dermatitis, as determined by a clinician. * (controls only): Any significant dermatological condition as determined by a clinician. * Currently using medication for any skin disease/condition and could not, in the opinion of the investigator, tolerate restriction or discontinuation of the medication as required by the study.