Atopic Dermatitis Phenotypes in Preschool and School-Age Children: A Latent Class Analysis

Background: Atopic dermatitis (AD) is the most common chronic inflammatory skin disease in childhood. Few data are available about AD phenotypes and their nationwide distribution. Methods: We performed a cross-sectional multicenter study involving some of the main Italian pediatric allergy centers from 9 Italian cities. A structured questionnaire was administered to 371 children with AD. Patients were divided in 2 groups: preschool children (aged <= 5 years) and schoolchildren (aged 6-14 years). A latent class analysis was used to detect AD phenotypes and to investigate their association with risk factors and other atopic diseases. Results: Latent class analysis identified 5 AD phenotypes in preschoolers (moderate-severe AD, high comorbidity, 8%; moderate-severe AD, low comorbidity, 35%; mild AD, low comorbidity, 20%; mild AD, respiratory comorbidity, 32%; mild AD, food-induced comorbidity, 5%) and 4 AD phenotypes in schoolchildren (moderate-severe AD, high comorbidity, 24%; moderate-severe AD, low comorbidity, 10%; mild AD, low comorbidity, 16%; mild AD, respiratory comorbidity, 49%). Parental history of asthma and eczema, early day-care attendance, and exposure to molds were significantly associated with the moderate-severe AD, high comorbidity phenotype in preschool children (P<.05). The moderate-severe AD phenotypes were also associated with the highest burden in terms of medication use and limitations in daily activities. Conclusions: The detection of different AD phenotypes highlights the need for a stratified approach to the management of this complex disease and for further studies to predict the course of AD and to develop more efficient therapeutic strategies.