Atopic dermatitis represents a real challenge in public health as it affects a large percentage of children and adults. Affected individuals must cope with a significant psychosocial burden, in addition to dealing with the medical aspects of the disease.

The purpose of this exploratory study is to collect clinical severity AD data, using PO-SCORAD (self-assessment by the subjects), SCORAD evolution, instrumental measurements and treatment follow up of subjects.

The future objective is to develop a personalised prediction model of AD flares in order to improve management of AD by more accurate severity evaluations by the subject and the physician. Development of a method of early detection of flares will open new treatment pathways for AD management.

This study will be conducted as a French monocentric exploratory study in adults with mild to moderate Atopic Dermatitis, and will be conducted on a maximum 25 included subjects.

The clinical study will include 4 study visits, after inclusion visit, and the maximum duration of the study for each subject will be 3 months : Day 1, Day 29, Day 57, Day 85.

In case of AD flare suspicion, the investigator may recommend a complementary visit. Any complementary visit will be confirmed by investigator according to the subject's information: photographs and PO-SCORAD sent by the subject. If visit is confirmed, it will be scheduled as soon as possible.

The objectives are:

• to collect clinical AD severity data in order to evaluate natural AD evolution with clinical and subject's scales, during a three-month period.
• to collect non-invasive instrumental AD data on a target area and on adjacent area: cutaneous hydration, epidermal barrier conditions and colorimetric parameters on cutaneous erythema
• to examine clinical and instrumental AD data
• to collect illustrative photographs of AD lesions

Only most important inclusion and exclusion criteria are listed : those which are study specific.

Inclusion Criteria:

• Subject suffering from Atopic Dermatitis according to the U.K. Working Party's Diagnostic Criteria for Atopic Dermatitis (3).
• Subject with mild to moderate Atopic Dermatitis with 20 <= SCORAD <= 40 at inclusion
• Subject with flare frequency ≥ 4 over the last year
• Subject with a cutaneous target area, allowing the measurements, located on upper or lower limbs and defined as a usual AD flare area according to the subject
• Subject owning a smartphone suitable with the 5.0 downloaded version of PO-Scorad® app
• Subject who agrees to use daily a free mobile app: PO-Scorad®

Exclusion Criteria:

• Subject having received artificial UV exposure or excessive exposure to natural sunlight within the 2 weeks before the inclusion visit or planning to be exposed to excessive or prolonged natural sunlight or UV exposures for the duration of the study
• Subject with a hirsute target area
• Systemic immunosuppressive therapy (excepted systemic corticoids) within 3 months before the inclusion visit or ongoing at inclusion visit.
• Systemic corticoids taken (whatever the number of intake) within 4 weeks before the inclusion visit or ongoing at inclusion visit.
• Phototherapy performed within 4 weeks before the inclusion visit or ongoing at inclusion visit
• Systemic antibiotics taken within 7 days before the inclusion visit or ongoing at inclusion visit.
• Moderate to high-potency topical corticosteroids applied within 7 days on upper or lower limbs before the inclusion visit or ongoing at inclusion visit
• Topical immunomodulators (TIMs), applied within 7 days on upper or lower limbs before the inclusion visit or ongoing at inclusion visit
• Any topical treatment or product applied between the evening before the inclusion visit and the inclusion visit
• Water applied on target area within 4 hours before the inclusion visit