Atopic dermatitis (AD) is a heterogeneous disease and many attempts have been made to define subsets of patients based on clinical characteristics. However, the current characterization of patients with AD might not adequately reflect the pathophysiologic diversity within patients with AD. This article reviews current biomarkers for AD and future perspectives. In the future, patients with AD will be stratified based on biomarker expression levels in body fluids and tissue, genetic variants, or combined biomarker expression patterns. With new targeted therapies for AD currently investigated in clinical trials this will lead to better identification of patients that can benefit from these highly specific, but expensive new treatments.