Echographic measurement of skin thickness in sites suitable for intradermal vaccine injection in infants and children.

Whereas the knowledge of skin thickness is essential to determine microneedle length and ensure proper administration of and better responses to intradermal vaccines, very few figures are available, especially in infants and children. Using ultrasound echography, we investigated skin thickness in 384 children aged 4-7, 12-18, and 54-66 months at potential body sites for intradermal vaccine delivery: deltoid, suprascapular, upper back, and lumbar area. The mean epidermis plus dermis thickness was significantly higher at the suprascapular than at the deltoid site (1.29mm vs. 1.22mm) and remained relatively unchanged whatever the BMI, age, sex, and skin phototype. In the 43 children aged 54-66 months, the mean skin thickness was significantly higher in the upper than in the lumbar area (1.39mm vs. 1.31mm). In this study setting, the heterogeneity in skin thickness cannot be considered sufficient to indicate various microneedle lengths for various ages or injection sites.