Serum levels of thymus and activation-regulated chemokine can be used in the clinical evaluation of atopic dermatitis.

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by the predominant infiltration of Th2-type cells in lesional skin. Thymus and activation-regulated chemokine (TARC) is overproduced in AD patients, and its serum levels are significantly higher in individuals with AD than in those with other inflammatory skin diseases.

Objectives: The purpose of this study was to examine whether serum levels of TARC can assess the severity of AD and be used in the clinical evaluation of AD.

Methods: A total of 73 AD patients, 11 patients with generalized atopic eczema (AE), and 30 healthy control subjects were enrolled. SCORAD (SCORing of Atopic Dermatitis) indices were calculated according to skin symptom scores. The Th2 chemokines TARC kit was then used to obtain serum TARC values in each group. Finally, statistical analysis was used to identify any correlations between serum TARC level and SCORAD index in AD and AE patients.

Results: Mean serum TARC values were 159.95 in healthy controls, 146.46 in the mild AD group, 202.71 in the moderate AD group, 1216.61 in the severe AD group and 1554.50 in the severe AE group. The serum TARC level was significantly correlated with SCORAD score in AD patients (P < 0.01). However, there was no significant correlation between SCORAD score and TARC in AE patients (P = 0.610).

Conclusions: The serum TARC level can be used to assess the severity of AD and as a reference index for the fast clinical evaluation of AD.