Pilonidal sinus disease: MedlinePlus Medical Encyclopedia

P Pilonidal sinus disease is an inflammatory condition involving the hair follicles that can occur anywhere along the crease between the buttocks, which runs from the bone at the bottom of the spine (sacrum) to the anus. The disease is benign and has no association with cancer.
P Pilonidal dimple may appear as:
- A pilonidal abscess, in which the hair follicle becomes infected and pus collects in the fat tissue
- A pilonidal cyst, in which a cyst or hole forms if there has been an abscess for a long time
- A pilonidal sinus, in which a tract grows under the skin or deeper from the hair follicle
- A small pit or pore in the skin that contains dark spots or hair

T Considerations
P Symptoms may include:
- Pus may drain to a small pit in the skin
- Tenderness over the area after you are active or sit for a period of time
- Warm, tender, swollen area near the tailbone
- Fever (rare)
P There may be no symptoms other than a small dent (pit) in the skin in the crease between the buttocks.

T Causes
P The cause of pilonidal disease is not clear. It is thought to be caused by hair growing into the skin in the crease between the buttocks.
P This problem is more likely to occur in people who:
- Are obese
- Experienced trauma or irritation in the area
- Have excess body hair, particularly coarse, curly hair

T Home Care
P Wash normally and pat dry. Use a soft bristle scrub brush to prevent the hairs from becoming ingrown. Keep the hairs in this region short (shaving, laser, depilatory) which may decrease risk of flare-ups and recurrence.

T When to Contact a Medical Professional
P Call your health care provider if you notice any of the following around the pilonidal cyst:
- Drainage of pus
- Redness
- Swelling
- Tenderness

T What to Expect at Your Office Visit
P You will be asked for your medical history and given a physical examination. Sometimes you may be asked for the following information:
- Has there been any change in the appearance of the pilonidal sinus disease?
- Has there been any drainage from the area?
- Do you have any other symptoms?
P Pilonidal disease that causes no symptoms does not need to be treated.
P A pilonidal abscess may be opened, drained, and packed with gauze. Antibiotics may be used if there is an infection spreading in the skin or you also have another, more severe illness.
P Other surgeries that may be needed include:
- Removal (excision) of the diseased area
- Skin grafts
- Flap operation following excision
- Surgery to remove an abscess that returns

T Alternative Names
P Pilonidal abscess; Pilonidal sinus; Pilonidal cyst; Pilonidal disease

T Images
- Anatomical landmarks, back view
- Pilonidal dimple

T References
P Coates WC. Disorders of the anorectum. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 96.
P Ferri FF. Pilonidal disease. In: Ferri FF, ed. Ferri's Clinical Advisor 2016. Philadelphia, PA: Elsevier; 2016:963.
P Kliegman RM, Stanton BF, St Geme JW, Schor NF. Surgical conditions of the anus and rectum. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 344.
P Sternberg JA. Management of pilonidal disease. In: Cameron JL, Cameron AM, eds. Current Surgical Therapy. 11th ed. Philadelphia, PA: Elsevier Saunders; 2014:293-401.

T Review Date 2/23/2016
P Updated by: Todd Campbell, MD, FACS, Clinical Assistant Professor, RowanSOM, Department of Surgery; Inspira Medical Group Surgical Associates, Elmer, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

