As structured and detailed data on the management of AD, a common chronic inflammatory skin disease which has a high impact on patients' quality of life and socioeconomic burden, are not available in Switzerland, the planned registry will overcome this gap. It will provide data on the medical care of patients with AD for health care research and allow to study the efficacy and safety of approved and available therapies for AD in daily life.

A prospective, non-interventional, national multicenter study in patients with moderate-to-severe AD. According to the availability of approved systemic drugs for the treatment of AD, the study will include children ≥12 years, adolescents and adult patients.

The general goal of the AD registry TREATswitzerland is to provide the scientific community with a disease-oriented prospective cohort of patients suffering from moderate-to-severe AD.

The primary objective of the AD registry is the documentation of medical care given to patients with moderate-to-severe AD in order to assess the appropriateness of care.

Further objectives of the AD registry are:

1. to evaluate the psychosocial impact of AD;
2. to provide up-to-date epidemiologic data that allow investigating risk factors for favorable or unfavorable disease courses and comorbidities; and
3. to establish a research network and foster clinical research projects.

The study procedures include:

• No study related intervention will be performed
• Patients have to fulfill all inclusion criteria to be enrolled in the study.
• Included patients are prospectively followed for at least 24 months. A maximum duration of follow-up is not intended.
• During the observation period, standardized study visits are performed to prospectively document patient characteristics, clinical data, patient-reported outcomes, reasons for treatment decisions, and satisfaction with treatment.

Inclusion Criteria:

• Age ≥ 12 years
• AD according to the UK Working Party's Diagnostic Criteria (28)
• Moderate to severe AD as defined by
• objective SCORAD > 20 or IGA ≥ 3 (moderate) or
• currently on systemic antiinflammatory therapy for AD or
• previous systemic antiinflammatory therapy for AD within past 24 months

Exclusion Criteria:

• refusal to sign the informed consent form

The study aims at including 700 patients with moderate to severe atopic dermatitis in the registry.