A standardized 60-second hair count is a reliable method when assessing hair shedding, according to an article released on June 16, 2008 in the Archives of Dermatology, one of the JAMA/Archives journals.
According to the study, assessment of shedding, as opposed to baldness, is not standardized across the medical profession. It is widely believed that it is normal to shed 100 hairs each day, which is based on the assumption that the average scalp has 100,000 hairs, and 10% of these are in the resting phase. However, this popular opinion has not been validated scientifically, and does not account for different rates based on age or gender.
In order to investigate the shedding of hairs, Carina A. Wasko, M.D., of Baylor College of Medicine, Houston, and colleagues investigated 60 healthy men, half aged between 20 and 40 years, and half aged between 41 and 60 years, who showed no evidence of baldness, or alopecia. The participants were given identical combs and the directions to wash their hair with the same brand of shampoo for three consecutive mornings. On the fourth day, they were asked to comb their hair forward for 60 seconds over a cloth of contrasting color before shampooing, then count the number of hairs that were shed. This process was repeated for three consecutive days, then repeated in eligible participants six months later.
From these results, the researchers were able to summarize. Between the ages of 20 and 40 years, between 0 and 78 hairs were shed, with an average loss of 10.2 hairs per 60 second test. Between the ages of 41 and 60, between 0 and 43 hairs were shed, with an average loss of 10.3 hairs per 60 second test. These results were consistent from day to day for all participants. The authors write: “When repeated six months later in both age groups, the hair counts did not change much. The hair counts were repeated and verified by a trained investigator, with results similar to those of subject hair counts.”
The authors conclude that this test is a reasonable standardized measure for hair loss. “In summary, the 60-second hair count is a simple, practical and objective tool for monitoring conditions associated with hair shedding,” they say. “Low intrapatient variability demonstrates that dependable results over an extended period of time are obtainable. The similarity between investigator and subject hair counts indicates that patients can reliably count hairs.” They also indicate the need for further experimentation: “Studies of the 60-second hair count in normal women and in the setting of hair disease still need to be performed.”
Standardizing the 60-Second Hair Count
Carina A. Wasko, MD; Christine L. Mackley, MD; Leonard C. Sperling, MD; Dave Mauger, PhD; Jeffrey J. Miller, MD
Arch Dermatol. 2008;144(6):759-762.
Written by Anna Sophia McKenney