BackgroundPemphigus vulgaris (PV) and pemphigus foliaceus (PF) are autoimmune blistering diseases targeting desmoglein 3 (Dsg3) or desmoglein 1 (Dsg1). The current scoring system, pemphigus disease area index (PDAI), has limitations including inter‐ and intra‐evaluator variability, as well as a time‐consuming evaluation process.ObjectivesTo identify objective and quantitative surrogate markers for assessing disease severity in PV and PF.MethodsEleven PV and PF patients were included. PDAI scores and candidate biomarkers [anti‐Dsg3 antibody, anti‐Dsg1 antibody, thymus and activation‐regulated chemokine (TARC)/CCL17, immunoglobulin E (IgE) levels and eosinophil counts] were measured before oral corticosteroid treatment. Pearson's correlation coefficient was used for correlations between PDAI and candidate biomarkers.ResultsSerum TARC/CCL17 levels significantly correlated with PDAI scores in PV and PF (R = 0.72, p = 0.02), while anti‐Dsg3 antibody levels correlated with PDAI scores for PV (R = 0.86, p = 0.012). No significant correlations were observed for anti‐Dsg1 antibody, eosinophil counts or IgE levels.ConclusionsSerum TARC/CCL17 may be a quantitative and unbiased disease biomarker in pemphigus patients, although further studies involving larger patient cohorts are needed.