pilonidal fistula
pilonidal sinus

Material from the cyst may drain through the pilonidal sinus.

The only way to get rid of a pilonidal sinus is to cut it out with a wide margin of surrounding healthy tissue.

Plewig and Kligman added another element to their acne triad, pilonidal sinus.

A pilonidal cyst is a pilonidal sinus that is obstructed.

In more severe cases, the cyst may need to be lanced or surgically excised (along with pilonidal sinus tracts).

However, unlike pilonidal sinus in humans, dermoid sinus in dogs is a neural tube defect.

In older children and adults, the tumor may be mistaken for a pilonidal sinus, or it may be found during a rectal exam or other evaluation.

It is also known (apparently incorrectly) as pilonidal sinus because it resembles pilonidal sinus in humans.

Plewig et al. noted that this new "acne tetrad" includes all the elements found in the original "acne triad", in addition to a fourth element, pilonidal sinus.

In 1975, Plewig and Kligman, following Pillsbury's research path, modified the "Acne triad", replacing it with the "Acne tetrad: acne triad, plus pilonidal sinus".

A number of morphological studies from this period focus on the causes of pilonidal sinus disease disease and of tract-forming suppurative hidradenitis as well the embryology and function of the pelvic structures.

A pilonidal cyst, also referred to as a pilonidal abscess, pilonidal sinus or sacrococcygeal fistula, is a cyst or abscess near or on the natal cleft of the buttocks that often contains hair and skin debris.