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 wer e measured on the forehead and back of men, and on the forehead, cheek , and back of women.with acne. Hair growth was assessed by computerize d image analysis (phototrichogram), and sebum excretion by computer an alysis using Sebutape(R). In patients with acne, marked differences we re revealed when results were compared with recent data from healthy p ersons. In particular, the mean growth rate of vellus hairs was higher , whereas the percentage of anagen hairs was lower, and the duration o f the anagen phase shorter in patients with acne than in healthy indiv iduals. 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 g rowth revealed significantly higher values in females than in males fo r (i) percentage of anagen hairs (P > 0.01), (ii) for vellus hair leng th (P < 0.05), and (iii) for the duration of the anagen phase (P < 0.0 1). The present study demonstrates that the activity of the vellus hai r follicle is influenced by acne, and vice versa, and therefore its ro le in the aetiopathogenesis of acne should be reconsidered.