Atopic dermatitis is a common disease which affects about one million people in Finland at some stage of their life. In atopic dermatitis we see a superficial inflammation of the skin and a defect in skin barrier function. The filaggrin protein plays a central role in the skin barrier function and studies indicate that about 30% of patients with atopic dermatitis have a mutation in the filaggrin gene. The aim of the study is to investigate whether a mutation in the filaggrin gene affects the clinical treatment outcome in patients with atopic dermatitis. If a mutation predisposes to a worse response to treatment, this could be examined and those patients with the mutation could be given extra treatment support for their atopic dermatitis. The prevalence of filaggrin mutation in the Finnish non-atopic population is studied in the control group.

Inclusion Criteria (patients with atopic dermatitis):

• Age at least 18 years
• Clinical diagnosis of atopic dermatitis
• Need for follow-up at the Skin and Allergy Hospital
• Patient gives signed informed consent to participate in this study
• Patients parents and grandparents are of Finnish origin

Inclusion Criteria (Controls):

• No history of atopy or skin disease
• Age at least 18 years

Patients with atopic dermatitis who are followed-up at the Skin and Allergy Hospital in Helsinki for at least one year can be included in the study.

The control population consists of non-atopic persons without any other skin disease (samples for the control population are applied for from a sample collection of the National institute for health and welfare).