Background: Atopic dermatitis (AD) is an inflammatory skin disease characterized by both acute and chronic eczema. Various markers are used to clinically evaluate the severity of AD. In order to identify a marker of local severity of AD, we measured IL-8, IL-18, vascular endothelial growth factor (VEGF), and transforming growth factor-α (TGF-α) levels in the stratum corneum (scIL-8, scIL-18, scVEGF and scTGF-α) and evaluated the correlation between the levels of these cytokines and the clinical severity scores of localized skin lesions. Methods: Stratum corneum samples were collected from the skin lesions of 50 patients with AD using the tape-stripping technique, and the scIL-8, scIL-18, scVEGF and scTGF-α levels were evaluated using the ELISA method. The trans-epidermal water loss and skin water content of the lesions were also measured prior to tape stripping. Results: The levels of scIL-8, scIL-18, scVEGF and scTGF-α were significantly higher in patients with AD than in healthy controls. Additionally, the levels of scIL-8, scIL-18 and scVEGF significantly correlated with the severity of AD. Conclusions: Among these cytokines, scIL-8 showed the highest correlation with the severity scores of lesions in AD as well as other parameters. Our results also suggest that measuring cytokines in the stratum corneum by using ELISA combined with tape stripping is a convenient method to evaluate the severity of skin lesions in AD.

Background: Atopic dermatitis (AD) is an inflammatory skin disease, characterized by existence of both acute and chronic eczema. Various markers are used to clinically evaluate the severity of AD as a whole. However, little is known regarding markers that can efficiently indicate the severity of a localized lesion. Vascular endothelial growth factor (VEGF), a potent activator of vascular permeability, is known to be increased in AD lesions. In order to establish whether the VEGF content in the stratum corneum (scVEGF) can be used as a marker to evaluate severity of AD lesions, we evaluated the association between scVEGF and symptom scores of localized lesions. Methods: Fifty patients with AD and 12 healthy subjects were enrolled. Skin lesions were evaluated and transepidermal water loss and skin water content of the lesions were measured. Stratum corneum samples were collected from the skin of back, neck and arm by the tape stripping technique. The scVEGF were evaluated using a VEGF-specific ELISA method after extracting protein from the scales. Results: The scVEGF levels were significantly higher in patients with AD than in healthy controls. Moreover, the scVEGF levels highly correlated with the manifestation scores of erythema and edema/papulation, and weakly correlated with the scores of excoriation, xerosis and itch. They also correlated significantly with transepidermal water loss and skin water content. Conclusions: The scVEGF levels correlated well with the severity of clinical conditions, especially erythema and edema/papulation. scVEGF level is considered to be a useful marker to evaluate acute inflammatory conditions in individual AD lesions.