The pilonidal sinus (pilus = hair, nidus = nest) is an acute abscessing or chronically secreting inflammation in the subcutaneous fat tissue in the region of the coccyx.
The clinical picture usually occurs in the 2nd to 3rd decade of life, often in men with pronounced hair in the gluteal region before the age of 40. Its development seems to be based on a multifactorial event triggered by the following mechanism: rubbing the buttocks together drives broken hair with the ends near the roots into the skin. This creates so-called pori or pits, i.e. deepening that can contain hair. Since the horny scales of the hair act as barbs, the hair penetrates deeper and deeper into the subcutaneous fatty tissue. A foreign body granuloma develops there that does not heal spontaneously (asymptomatic form), but can become infected (abscessing and chronic form). Heavy hair and excessive sweat secretion seem to favor the development of the pilonidal sinus.
A bland pilonidal sinus does not require therapy. In the case of the acutely festering form, there are indications that purification of the pus focus, followed by secondary treatment of the pilonidal sinus in the inflammation-free interval using one of the treatment methods described below, is advantageous. Excision is currently the standard treatment for chronic pilonidal sinus.
Open wound treatment with secondary wound healing is a safe procedure in terms of the complication rate, but it is associated with a long wound healing time and a not insignificant recurrence rate (recurrence up to 30%). The minimally invasive techniques – including the so-called pit-picking – also represent a treatment option for the chronic manifestation, whereby a higher recurrence rate must be expected compared to the excision techniques. However, they can be used as the first method for uncomplicated pilonidal sinus. If minimally invasive methods are not used, plastic (asymmetric) techniques and sliding flaps should be used, for example limber flap plastic, which also has a very low recurrence rate (<3%).