Age incidence of Pityrosporum orbiculare on human skin.

We have investigated the incidence of the lipophilic fungi Pityrosporum orbiculare and P. ovale on clinically normal skin in newborn children and in children at the age of 6 months, 1 year, 5 years, 10 years, and 15 years. P. orbiculare was absent in children of less than 5 years of age. It was present in the highest incidence (93%) in the 15-year-old children, about the same frequency as in adults. The colonization starts during the period when the sebaceous glands become active. P. ovale could not be cultured and this may depend on geographical variations in the distribution of these yeasts.