THE VELLUS HAIR FOLLICLE IN ACNE - HAIR-GROWTH AND SEBUM EXCRETION

In this study we investigated the activity of the vellus hair follicle in acne. Hair growth and sebum excretion in vellus hair follicles were measured on the forehead and back of men, and on the forehead, cheek, and back of women.with acne. Hair growth was assessed by computerized image analysis (phototrichogram), and sebum excretion by computer analysis using Sebutape(R). In patients with acne, marked differences were revealed when results were compared with recent data from healthy persons. In particular, the mean growth rate of vellus hairs was higher, whereas the percentage of anagen hairs was lower, and the duration of the anagen phase shorter in patients with acne than in healthy individuals. Hair growth and sebum excretion depended significantly (P < 0.01) on the anatomical site (forehead 414 hairs/cm2, 0.053 mm/day, 34%; back 93 hairs/cm2, 0.16 mm/day, 21%). In addition, analysis of hair growth revealed significantly higher values in females than in males for (i) percentage of anagen hairs (P > 0.01), (ii) for vellus hair length (P < 0.05), and (iii) for the duration of the anagen phase (P < 0.01). The present study demonstrates that the activity of the vellus hair follicle is influenced by acne, and vice versa, and therefore its role in the aetiopathogenesis of acne should be reconsidered.