Regional variations in density of cutaneous propionibacteria: correlation of Propionibacterium acnes populations with sebaceous secretion.

Cutaneous Propionibacterium acnes populations were quantitatively measured in 33 young adults and compared with the rate and composition of sebum secretion in nine skin regions. Bacteriological and lipid analyses were performed on the forehead, cheek, anterior chest, abdomen, lower back, volar forearm, upper inner arm, thigh, and calf. P. acnes populations in these sites correlated significantly with the total amount of lipid produced (r = 0.77) as well as with di- and triglycerides (r = 0.68), squalene and wax esters (r = 0.72), cholesterol and cholesterol esters (r = 0.67), and free fatty acids (r = 0.67).