The correct answer is poliosis (choice “d”), which has been described as a reliable indicator of tuberous sclerosis when seen early in life.1 Poliosis is the specific term for focal loss of color in scalp hair. Technically, this process is a form of hypomelanosis (choice “b”), although the latter is a more generic term used to refer to loss of pigment in any area. Graying (choice “a”) usually refers to uniform loss of hair color all over the scalp—albeit with focal accentuation over the temples, as opposed to the sharply demarcated areas of complete color loss seen in poliosis. Poliosis can be seen as a feature of vitiligo (choice “c”), but the latter usually also involves pigment loss elsewhere.
Poliosis, which is often idiopathic, can be seen in a number of conditions besides tuberous sclerosis and vitiligo, including halo nevi of the scalp, alopecia areata (as hair regrows), and Waardenburg’s syndrome. As mentioned above, it can appear early in life as an indicator of tuberous sclerosis, particularly when coupled with involvement of adjacent dermatomal skin. This was likely the case with this patient. No permanent treatment exists for this problem.
1. Apibal Y, Reakatanan W, Chunharas A. Poliosis as the first clue of tuberous sclerosis. Pediatr Dermatol. 2008;25(4):486-487.