The pilonidal cyst ("pilus": hair) is an acute or chronic inflammation in the subcutaneous fatty tissue, predominantly in the region of the coccyx, i.e. at the upper end of the bottom fold. Commonly, the disease is usually referred to as tailbone fistula; less common terms are pilonidal sinus, pilonidal disease, hair nest pits and hair fistula. The disease was first described in 1833. The frequency of the pilonidal cyst and tailbone fistula shows an increasing tendency for unknown reasons.
Three types of fistula are distinguished: the accidentally discovered form, which does not cause any discomfort, the acute abscess formation and the chronic form. Usually granulation tissue, which is inferior connective tissue, hair and cell detritus, is found in the cyst-shaped sinus. The latter is a mushy, unstructured and usually greasy mass that develops due to an inflammatory melting of tissue.
For the development of a pilonidal cyst several factors must coincide, whereby the hair roots in the area of the gluteal fold play a decisive role. More details can be found in the chapter "Causes off pilonidal cysts". Young men of dark hair type develop a coccyx fistula disproportionately frequently.
There are a variety of treatment methods for the pilonidal cyst and its fistula. The most common method is to generously cut out the affected area with an open wound treatment. This means that the wound is not sutured, but provided with tamponades that have to be changed daily. The procedure is safe, but for those affected it means months of healing with correspondingly long restrictions for leisure activities and, if necessary, time off work. "Safe" means that the procedure is not risky and also quick, but it does not protect against recurrences, i.e. the recurrence of the pilonidal cyst and fistula.
Literature sources:
Anderson NP (1947) Cysts, sinuses and fistulas of dermatologic interest. J Am Med Assoc 135:607– 612
Da Silva JH (2000) Pilonidal cyst: cause and treatment. Dis Colon Rectum 43:1146–1156
Hull TL, Wu J (2002) Pilonidal disease. Surg Clin North Am 82: 1169-1185
