These filaments are naturally occurring, and are especially prominent on the nose.[3][2]: 64 They are typical among those with naturally oily skin and large pores, even if those individuals have ceased to produce acne.[2]: 64 They are not a sign of infection or any other ailment including acne,[2]: 16 and are commonly mistaken for, though cannot form,[2]: 26 blackheads. Expression, or squeezing, is discouraged as sebaceous filaments are a natural part of healthy human skin. As such, squeezing can lead to unintentional unnecessary harm, such as scarringorinflammation.[citation needed] They help to channel the flow of sebum within a given pore, allowing it to seep gradually to the surface. In 1979, David A. Whiting described them in a review in the Western Journal of Medicine as "a loose, porous mass of horny detritus".[1]
