Correlation of skin barrier impairment in atopic dermatitis with aeroallergen sensitization

Background: Atopic dermatitis (AD) often predates the development of allergic sensitization in the so-called atopic march. Several studies have pointed out epidermal barrier impairment as a major cause of this evolution. Objective: The present study aimed to assess atopic skin integrity by means of transepidermal water loss (TEWL) and Corneometer, and to investigate possible correlations between barrier integrity measurements and the degree of sensitization to aeroallergens (allergy score). Methods: Sixty-one children (6 months to 17 years old) with AD were clinically evaluated by the Scoring Atopic Dermatitis index. TEWL and Corneometer evaluations were performed on lesion sites as well as on healthy skin. The subjects underwent skin-prick testing, and the severity of allergic sensitization was assessed for each patient by summing all wheal diameters (the allergy score). The same tests were performed in 20 children without AD. Results: In patients with AD, TEWL and Corneometer results were found to be higher and lower, respectively, on eczematous areas in comparison with healthy skin, and differences were significantly correlated to the Scoring Atopic Dermatitis index (p < 0.0001 and p = 0.007, respectively). The TEWL result was significantly higher in nonlesional skin of the patients with AD compared with that of individuals without AD (p = 0.017). Of the patients with AD, 59% were sensitized to inhalant allergens; allergy scores were positively correlated with both AD duration (r = 0.63; p < 0.0001) and nonlesional skin TEWL values (r = 0.46; p = 0.002). No significant correlation was found between allergy scores and skin parameters in subjects without AD. Conclusion: Patients with AD are affected by barrier function impairment, even on noneczematous skin. This defect is associated with greater aeroallergen sensitization and may contribute to allergic respiratory symptom development.