Over the last several decades, a great number of research exploring the relationship between the severity of atopic dermatitis and different biomarkers have been published. The goal of this study was to find, analyze, and synthesize literature investigating the connection of biomarkers with disease severity in atopic dermatitis patients, which has never been done before. Three electronic databases were examined methodically, and suitable studies were chosen for inclusion. A total of 222 papers were critically reviewed, reporting on 115 distinct biomarkers in 30 063 patients. The studies were split into two categories. The first category included longitudinal randomized controlled trials and cohort studies that provided data at several time periods. The second segment included cross-sectional studies that only reported one measurement per subject. 108 of the 222 publications supplied enough data for meta-analysis. Only four biomarkers from the longitudinal group and nine from the cross-sectional group were qualified for meta-analysis.

The most reliable biomarker investigated was serum thymus and activation-regulated chemokine (TARC), which had pooled correlation values of 0.60 and 0.64 in longitudinal and cross-sectional investigations, respectively. Serum cutaneous T-cell attracting chemokine (CTACK), sE-selectin, macrophage-derived chemokine (MDC), lactate dehydrogenase (LDH), and interleukin (IL)-18 are other biomarkers that may be helpful but require further investigation.