Pilonidal disease is a type of skin infection which typically occurs as a cyst between the cheeks of the buttocks and often at the upper end. Symptoms may include pain, swelling, and redness. There may also be drainage of fluid, but rarely a fever.Risk factors include obesity, family history, prolonged sitting, greater amounts of hair, and not enough exercise. The underlying mechanism is believed to involve a mechanical process. The lesions may contain hair and skin debris. Diagnosis is based on symptoms and examination.If there is infection, treatment is generally by incision and drainage just off the midline. Shaving the area and laser hair removal may prevent recurrence. More extensive surgery may be required if the disease recurs. Antibiotics are usually not needed. Without treatment the condition may remain long term.About 3 per 10,000 people per year are affected, and it occurs more often in males than females. Young adults are most commonly affected. The term "pilonidal" means "nest of hair". The condition was first described in 1833. Signs and symptoms
Pilonidal cysts are itchy and often very painful, and typically occur between the ages of 15 and 35. Although usually found near the coccyx, the condition can also affect the navel, armpit, the cheek, or the genital region, though these locations are much rarer.
Signs and symptoms may include:
Intermittent pain/discomfort or swelling above the anus or near the tailbone
Opaque yellow (purulent) or bloody discharge from the tailbone area
Unexpected moisture in the tailbone region
Discomfort sitting on the tailbone, doing sit-ups or riding a bicycle—any activities that roll over the tailbone areaSome people with a pilonidal cyst will be asymptomatic. Pilonidal sinus
Pilonidal sinus (PNS): is a sinus tract, or small channel, that may originate from the source of infection and open to the surface of the skin. Material from the cyst drains through the pilonidal sinus. A pilonidal cyst is usually painful, but with draining the patient might not feel pain. Causes
One proposed cause of pilonidal cysts is ingrown hair, although hairs found in pilonidal sinus tracts may originate from the head. Excessive sitting is thought to predispose people to the condition, as sitting increases pressure on the coccygeal region. Trauma is not believed to cause a pilonidal cyst; however, such an event may result in inflammation of an existing cyst; there are cases where this can occur months after a localized injury to the area. Some researchers have proposed that pilonidal cysts may be caused by a congenital pilonidal dimple. Excessive sweating can also contribute to the formation of a pilonidal cyst: moisture can fill a stretched hair follicle, which helps create a low-oxygen environment that promotes the growth of anaerobic bacteria, often found in pilonidal cysts. The presence of bacteria and low oxygen levels hamper wound healing and exacerbate a forming pilonidal cyst.