Pilonidal Sinus in Children and Teenagers

What is a pilonidal sinus?

A pilonidal sinus is a small tunnel or cavity that develops beneath the skin, usually in the crease between the buttocks (the natal cleft), just above the tailbone. It often contains loose hairs and skin debris and can become inflamed or infected.

Pilonidal sinus disease is most common in teenagers and young adults, particularly after puberty. It is thought to develop when loose hairs penetrate the skin, triggering inflammation and, in some cases, infection.

Some children have a pilonidal sinus without any symptoms, while others develop recurrent pain, swelling or abscesses that require treatment.

Our paediatric surgeons provide expert assessment and treatment for pilonidal sinus disease, helping children return to normal activities as quickly as possible.

What are the symptoms?

Symptoms vary depending on whether the sinus is infected.

Children and teenagers may experience:

  • A painful lump near the top of the buttocks
  • Redness and swelling
  • Tenderness when sitting
  • Discharge of blood or pus from a small opening in the skin
  • An unpleasant smell from persistent drainage
  • Recurrent episodes of pain and swelling
  • Fever if an abscess develops

Some patients notice only a small pit or dimple in the skin before symptoms begin.

When should I seek medical advice?

You should arrange an assessment if your child develops:

  • A painful lump near the tailbone
  • Persistent discharge from the area
  • Recurrent swelling or infections
  • Ongoing discomfort when sitting
  • A wound that does not heal

Urgent assessment is recommended if your child develops severe pain, a rapidly enlarging swelling, fever or significant pus, as these may indicate an abscess that requires prompt treatment.

How is a pilonidal sinus diagnosed?

A pilonidal sinus is usually diagnosed during a physical examination. Your consultant will examine the affected area, looking for:

  • Small skin pits or openings
  • Signs of infection
  • Swelling or abscess formation
  • Persistent drainage

Further investigations are rarely needed unless another diagnosis is suspected.

What treatment is available?

Treatment depends on the severity of the condition.

Conservative treatment

For mild symptoms, treatment may include:

  • Keeping the area clean and dry
  • Regular hair removal around the natal cleft (where appropriate)
  • Good hygiene
  • Avoiding prolonged pressure on the area
  • Antibiotics if there is surrounding skin infection (although antibiotics alone do not cure a pilonidal sinus)

Treatment for an abscess

If a painful abscess develops, it usually requires incision and drainage to release the infection and relieve pain.

Surgical treatment

If symptoms keep returning or the sinus causes ongoing problems, surgery may be recommended to remove the affected tissue.

Several surgical techniques are available, and your surgeon will recommend the most appropriate approach based on your child's condition. The aim is to remove the sinus while minimising the risk of recurrence and promoting good wound healing.

Recovery

Recovery depends on the type of procedure performed.

Following simple drainage of an abscess, discomfort usually improves rapidly over a few days.

After definitive surgery, healing may take several weeks, particularly if part of the wound is left open to heal naturally. Your surgical team will explain how to care for the wound and advise when your child can return to school, sport and other activities.

Good wound care and reducing hair accumulation in the area can help lower the risk of recurrence.