I must take issue with Dr Mahé's accusation that our "ignorance of these traumatic factors seems particularly unfortunate." I have considered, over and over again, the possibility that grooming practices contribute to the pathogenesis of various forms of scarring alopecia. I am far from ignorant of these practices, and counsel patients to avoid potentially traumatic styling. Nor do I dismiss the possibility that grooming practices exacerbate central, centrifugal scarring alopecia (CCSA)1 and acne keloidalis (AK). Traumatic grooming may very well explain the uneven sex ratios found in these conditions. But this is certainly not "proven" by the circumstantial and uncritical evidence supplied by Dr Mahé.
Sperling LC. Scarring Alopecia and Ethnicity. Arch Dermatol. 2001;137(3):375. doi: