The goal of this study was to instrumentally evaluate the skin of healthy infants and to compare it to adult skin. A total of 70 infants, 45 girls and 25 boys, ages 8-24 months, and 30 healthy women were studied by means of transepidermal water loss (TEWL), capacitance, and pH measurements at two different skin sites, the volar forearm and the buttocks. No significant differences in TEWL were found between infants and adults, either on the buttocks or on the volar forearm. On the contrary, capacitance values were higher in infants. Their skin also appeared less acid than that of adults, with high statistical significance. No TEWL, capacitance, or pH variations were observed in infants according to sex and age. On the basis of the above data, the skin of infants 8-24 months of age shows functional signs of immaturity. This may lead to an increased permeability and a reduced capacity for defense against chemical and microbial aggression.

Because definite clinical and histological criteria for the diagnosis of the congenital nature of naevi are lacking, the use of dermoscopy can be of great help in identifying those lesions where the presence of specific dermoscopic features makes the diagnosis of CN more likely. Moreover, dermoscopy can be useful both for the classification of lesions already identified as congenital according to definite clinical and anamnestic data and for a possible correlation of naevus phenotype and dermoscopic patterns to the risk of developing a malignant melanoma in prospective studies.