Poliosis circumscripta, commonly referred to as a "white forelock", is a condition characterized by localized patches of white hair due to a reduction or absence of melanin in hair follicles.

Although traditionally associated with the scalp, poliosis can affect any hairy area on the body, including eyebrows, eyelashes, and beards.

In addition to genetic factors, poliosis can develop due to various inflammatory, autoimmune, or neoplastic conditions, or as a side effect of medication.

Several genetic and acquired disorders can mimic poliosis, and they should be considered during diagnosis: Poliosis occurs in several genetic syndromes such as piebaldism, Waardenburg syndrome, neurofibromatosis type I, and tuberous sclerosis.

[16] It can also occur in conditions such as vitiligo, Vogt–Koyanagi–Harada disease, alopecia areata, and sarcoidosis, and in association with neoplasms and some medications.