A sebaceous filament is a tiny collection of

sebum A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest nu ...

and dead skin cells around a

hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction betwe ...

, which usually takes the form of a small, yellow to off-white hair-like strand when expressed from the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...

. These filaments are naturally occurring, and are especially prominent on the

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next pass ...

. They are typical among those with naturally oily skin and large pores, even if those individuals have ceased to produce

acne Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and ...

. They are not a sign of

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable d ...

or any other ailment including acne, and are commonly mistaken for, though cannot form 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

scarring A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs, and tissues of the body. Thus, scarring is a natu ...

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

. They help to channel the flow of sebum within a given pore, allowing it to seep gradually to the surface. David A. Whiting described them in his review in the ''

Western Journal of Medicine The ''Western Journal of Medicine'' was a peer-reviewed medical journal. It was established in 1856 as the ''Transactions of the Medical Society of the State of California''. It was renamed ''California State Journal of Medicine'' in 1902 and volum ...

'' as "a loose, porous mass of horny detritus".

References

Dermatologic terminology {{dermatology-stub