Background: We aimed to evaluate the influence of cold airflow from the air conditioner on skin barrier function and filaggrin degradation products (FDPs) in children with atopic deramtitis (AD).

Methods: In a case-control study, 28 children with AD and 12 normal children without AD were exposed to one of two air conditioner modes (conventional or wind-free) for 2 h. Skin temperature, transepidermal water loss (TEWL), and skin pH were measured on right cheek and forearm at pre-and post-exposure time points. We also measured filaggrin and FDPs from the volar surface of the forearm.

Results: In AD patients, skin temperature on the forearm decreased after exposure to the conventional and wind-free modes (P< 0.001 and P= 0.026), and TEWL on the cheek and the forearm decreased in the wind-free mode (P= 0.037 and 0.002). Skin pH on the cheek increased only after exposure to the conventional mode in AD group (P= 0.002). However, no changes in TEWL and skin pH were found after exposure to either the conventional or the wind-free mode in the control group. In AD children, the levels of pyrrolidone carboxylic acid (PCA) and cis-urocanic acid (UCA) were reduced only after exposure to the conventional mode (all P= 0.033). The percent changes of PCA and cis-UCA were higher in the AD group than those in the control group after exposure to conventional mode (P= 0.029 and 0.046).

Conclusions: Skin barrier function in children with AD may be altered by the exposure to cold airflow from a conventional air conditioner.