Sexual maturation effects changes in both structural and functional properties of the skin and its appendages. That these developments are in progress is indicated not only by the appearance of facial and body hair and the occurrence of acne but also by a biochemical sign: Conversion of the skin pH from acid to neutral or alkaline on the surface of one particular site, namely the axillary vault. In a previous report,1 we have described the sequence of the axillary pH changes in relation to the appearance of secondary sex characteristics in boys. In the present communication we will discuss the results of similar studies in girls.
Material and Methods
Skin pH determinations were made on 417 females ranging in age from 1 month to 17 years. While infants, children, and young adolescents were selected from hospital wards and private practice, the more mature adolescents were tested at the New