26 citations,
January 1993 in “Dermatology” Exclamation mark hairs are not exclusive to alopecia areata.
15 citations,
November 2016 in “Journal of The American Academy of Dermatology” Exclamation mark hairs suggest early scalp disease, while white dots indicate it's chronic.
April 2024 in “Journal of cosmetic dermatology” Children with alopecia areata have more exclamation mark hairs and fewer yellow dots than adults.