Facial and abdominal hair growth in hirsutism: a computerized evaluation

Methods of objectively assessing the growth rate of hairs in hirsute women have generally required some form of shaving and have focused on studying hairs affecting the face, which has reduced the number of patients willing or able to participate in such studies. A possible solution is to assess the terminal hairs on the lower abdomen (ie, the male escutcheon) because these two body areas are the most frequently affected with excess hair growth in hirsute patients. Nonetheless, it is unclear how the growth characteristics (density, diameter, and growth rate) of the hairs on the abdomen and face differ in these patients. We hypothesize that the growth characteristics of terminal hairs on the abdomen and face are similar and that evaluation of either area may be sufficient in assessing the hair growth rate of these patients. To objectively evaluate hair growth in the face and abdomen in hirsute patients, we developed a computer-aided image analysis system capable of measuring several growth parameters. Twenty hirsute women (12 white and 8 black), aged 31.2 +/- 6.1 years, were studied. Facial and abdominal skin areas were shaved, and 3 to 5 days later the areas were photographed through a calibrated glass plate and 5 terminal hairs were plucked from each area. The daily hair growth rate (assessed by photography and by direct measurement of the plucked hair), the density of hairs (number of hairs per surface area assessed by photography), and hair diameter (of the plucked hairs) were determined. The extent of hirsutism was also measured, albeit subjectively, by a modification of the Ferriman-Gallwey method, with each area given a score of 0 (no terminal hairs seen) to 4 (terminal hairs in a pattern similar to that of a very hirsute man). Facial, abdominal, and total Ferriman-Gallwey scores were 1.3 +/- 0.6, 1.8 +/- 0.9, and 12.5 +/- 5.4, respectively. Our results indicated that facial hairs were distributed in greater density and had a greater diameter than abdominal hairs (15.6 +/- 14.2 hairs/cm(2) vs 5.4 +/- 1.9 hairs/cm(2), and 84.5 +/- 19.5 microm and 66.2 +/- 17.5 microm, respectively, P <.005). Alternatively, the growth rates of facial and abdominal hairs were similar, whether determined photographically (0.36 +/- 0.18 mm/day vs 0.43 +/- 0.19 mm/day, respectively) or from plucked hairs (1.2 +/- +0.2 mm/d vs 1.4 + 0.4 mm/d, respectively). We conclude that although the density and diameter of facial hairs are greater than that of lower abdominal hairs, these areas have very similar growth rates. Hence evaluation of either of the body areas, using an objective method of assessing hair growth, should provide equivalent results.