Changes in villus‐like projections of corneocytes from the facial skin in normal infants with or without infantile eczema; useful parameter to assess barrier function

Background/Purpose Skin barrier function changes rapidly during the first year of life in infants. Measuring skin barrier function in infants is difficult because of the burden on patients and their parents or guardians. A simple method for assessing barrier function in infants that can be performed quickly and would enable swift treatment and skin care management. Methods We used laser microscopy to investigate villus‐like projections (VPs) observed on the lower surface of corneocytes obtained on tape strips from 18 normal Japanese infants at the ages of 1, 3, and 6 months. We also performed transepidermal water loss and corneocyte size measurements. A dermatologist clinically assessed the cutaneous findings. We rapidly measured skin barrier function changes during the first 6 months of life in infants. Results During the study period, very slight erythema and pityriasis were the primary reasons for skin rash, which were generally most severe at 3 months. The results showed that barrier function declined at approximately 3 months of age in nearly all subjects. Therefore, we found that normal barrier function of infantile skin becomes temporarily impaired after birth. Conclusion We conclude that even in patients with very mild skin rashes, multiple objective indices of skin barrier function deteriorate simultaneously. Observation of VPs on the surface of corneocytes using laser microscopy is a rapid, painless, and effective method of monitoring skin barrier function in infants, and VP score offers a useful index for assessing barrier function.