Serum <scp>TARC</scp> Levels Reflect the Severity and Prognosis of Atopic Dermatitis in Infants Under 6 Months of Age: A Retrospective Study in a Pediatric Primary Care Practice

This study evaluated the clinical utility of serum TARC levels as an objective biomarker in infants with atopic dermatitis (AD) under 6 months of age in pediatric primary care practice, a population for which evidence remains limited. A retrospective search identified 61 infants (median age: 4 months) diagnosed with AD using The UK Working Party criteria and the Japanese guidelines for atopic dermatitis. These findings suggested a strong correlation between serum TARC levels and Objective SCORAD, and proposed the cutoff value for serum TARC demonstrating mild and moderate-to-severe AD was 2100 pg/mL derived using ROC analysis. Furthermore, in the group classified as the moderate-to-severe group based on the cutoff value, the period required to the duration until discontinuation of topical anti-inflammatory drugs was significantly longer than in the mild group. The recurrence rate of AD up to age 5 was significantly higher in this group than in the mild group. It is interesting to note that the incidence rate of Japanese cedar pollen allergy up to age 5 was significantly higher in the moderate-to-severe group. Based on these findings, it is hoped that measuring serum TARC in early infants with AD will be clinically useful for assessing the severity and prognosis.