A pilonidal cyst is a fluid-filled, pimple-like sac at the coccyx (tailbone), just below the crack of the buttocks. Pilonidal cysts are prone to infection; if one does become infected, filling with pus, it is technically called a "pilonidal abscess." Pilonidal abscesses are always treated with excision and drainage because, left untreated, the infection can spread.
Causes of Pilonidal Cysts
Pilonidal cysts are thought to be caused by ingrown hairs (hair follicles are often found in the cysts) or trauma (they were common during World War II in soldiers who spent a great deal of time riding in jeeps, earning the nickname "Jeep disease"). Pilonidal cysts are most common in people between the ages of 15 and 24, and rarely occur in people older than 40. Those with a family history of pilonidal cysts are more likely to develop them.
Risk Factors for Pilonidal Cysts
Those with one or more of the following risk factors are more likely to develop pilonidal cysts:
- Inactive lifestyle or occupation
- Trauma at the site
- Excess body hair
- Stiff or coarse hair
- Poor hygiene
Having a deep cleft between the buttocks also increases the risk of developing pilonidal cysts.
Symptoms of Pilonidal Cysts
Symptoms of pilonidal cysts include the following:
- Pain and pressure at the bottom of the spine
- Swelling at the bottom of the spine
- Redness at the bottom of the spine
- Draining pus, particularly if malodorous
Fever is also a symptom of pilonidal cysts.
Diagnosis of Pilonidal Cysts
Physical examination is the first step in diagnosing a pilonidal cyst. A physician will be able to observe redness and swelling just above the anus, and inflammation of the surrounding skin. If the patient has a high white-blood-cell count, it confirms the diagnosis.
Treatment of Pilonidal Cysts
A common at-home remedy for a pilonidal cyst is soaking in a hot tub. Although this does not eliminate it, it facilitates the cyst's coming to a head, making it easier to lance.
Pilonidal cysts are usually infected with Staphylococcus aureus, and will not heal on their own, or with the administration of antibiotics alone. Rather, they must be surgically drained in one of several ways.
Incision and Drainage, with Packing
During this procedure, the surgeon makes an incision and drains the cyst, removing hair follicles, and packing the cavity with gauze. Although incision and drainage is a simple procedure that can be performed under local anesthesia, it requires frequent changing and repacking of gauze for up to 3 weeks.
In this outpatient procedure, the surgeon creates a pouch designed to heal without packing. Healing can take as long as 6 weeks, however.
Incision and Drainage, with Immediate Closure of the Wound
During this procedure, the surgeon drains and cleans the wound, and sutures it closed. Although there is no need for packing, and the wound heals fairly quickly, there is a good chance of the cyst's recurring.
Recovery from Pilonidal Cyst Removal
Pilonidal cyst removal is usually an outpatient procedure. Painkillers and anti-inflammatory medication are typically prescribed to prevent further infection, and keep the patient as comfortable as possible during healing.
Depending on the size of the cyst and the method of its removal, full recovery can take from a week to several weeks. The wound must be kept clean until it heals.