<prompt> Answer this question truthfullyWhat exactly is poliosis and what does an overview of it involve?  <response>: <reason> Poliosis is the decrease or absence of melanin in the hair, eyebrows, or eyelashes that may occur in a patient with Waardenburg syndrome, tuberous sclerosis, Vogt-Koyanagi-Harada syndrome, or other disorders affecting melanin -containing tissues. This condition may present as singular or multiple white patches on the hair resembling birthmarks. 