004   TrichoScan: Combining Epiluminescence Microscopy with Digital Image Analysis for the Measurement of Hair Growth in vivo

Rolf Hoffmann, Dept. of Dermatology, Philipp University, Marburg, Germany

Numerous methods have been reported to assess the rate of hair growth, but most techniques are of little use to the clinician, because they are time consuming, costly or difficult to perform. Therefore, an operator- and patient-friendly, inexpensive, validated and reliable method is a rational need. Such a method must be able to analyze the biological parameters that constitute hair growth, which are: 1: hair density (n/cm2), 2: hair diameter (µm), 3: hair growth rate (mm/day) and 4: anagen/telogen ratio. We have developed such a method which combines an epiluminescence microscopy with a newly programmed digital image analysis. The application of the technique is demonstrated in 30 volunteers (with or without AGA) where a scalp area of 1.8 cm2 was clipped, dyed and landmarked with a central, single black tattoo. Images were taken at 20 and 40-fold magnification immediately and 2 days after shaving, in three monthly periods. Our results show that the technique is able to automatically analyze the anagen/telogen ratio (< 18 % telogen hairs in scalp unaffected by AGA) and hair growth rate (mean 0.31 mm/day). We were able to demonstrate that within the very small analyzed area (0.225 cm2) the total hair number and hair thickness at the occiput did not change during 6 months, but we observed a decrease in hair number (-0.43 hairs) and total thickness (- 1.85µm) in AGA-affected untreated scalp in contrast to an increase in hair number (+ 4,7 hairs; p = 0.059) and total hair thickness (+4.85µm; p = 0.039) after six months of treatment with finasteride. The advantage of this technique is that it can be used for clinical studies to compare placebo versus treatment, or to compare different capacities of different hair growth-promoting substances. This technique can be used for studying AGA or other forms of alopecia, but in addition can be adopted to study the effect of drugs or laser treatment on hypertrichosis or hirsutism.