pilonidal sinus
Last reviewed 01/2018
'Pilonidal' means a nest of hairs. A pilonidal sinus is a sinus that contains a tuft of hairs. These sinuses are commonly found in the skin covering the sacrum and coccyx but can occur between the fingers, particularly in barbers, and at the umbilicus.
A pilonidal sinus is not lined by skin and there are no hairs growing within it. In fact, the hairs in the sinus are short, broken pieces of hair that either get sucked into a pre-existing dimple or actually pierce the normal skin in the gluteal cleft and then, by acting as foreign bodies, aid and support the development of chronic infection. The result is a chronic abscess which contains hair and which flares up at frequent intervals into an acute abscess.
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