The role of pH: a common misconception.
Diaper rash is caused in large part by an elevation in skin pH, rather than a more acidic pH as commonly believed. In 1955, the average pH of the perianal skin in breastfed infants has been reported to be between 5.3-5.552. However, prolonged exposure of the perianal region to urine and feces leads to a more alkaline pH, increasing the risk for diaper rash53. Fecal pH also plays a significant role in the development of diaper rash, in that fecal enzymes, which are activated by elevated pH, have a direct irritant effect on the skin54.