What Is Pilonidal Sinus and Who Gets It?

ايه هو الناسور العصعصي ومين بيصاب بيه؟

Pilonidal sinus disease occurs when loose hairs penetrate the skin of the natal cleft, triggering a foreign body reaction and chronic inflammation. Over time, this creates sinus tracts — small tunnels under the skin that harbor hair and debris, leading to recurrent infection and drainage.

Who is affected: The condition predominantly affects young males between ages 15 and 35. Risk factors include coarse or abundant body hair, a deep natal cleft, obesity, prolonged sitting (desk workers, drivers), and a sedentary lifestyle. It is uncommon after age 45 as the natal cleft becomes shallower and hair growth decreases with age.

How it presents: The typical patient notices intermittent pain and swelling at the top of the buttock crease, with discharge that may be clear, bloody, or purulent. Some patients experience acute episodes — a pilonidal abscess — with intense throbbing pain, redness, and swelling that may require emergency drainage. Between acute episodes, the chronic sinuses continue to drain and cause discomfort.

Why it recurs: Recurrence is the central problem in pilonidal sinus surgery. It happens for several reasons: incomplete excision leaving behind sinus tracts or hair follicles, midline wound placement (the depth of the natal cleft creates a moist environment that impairs healing and traps new hairs), poor surgical technique, and failure to address the underlying mechanism of hair penetration. The choice of surgical technique is the single most important factor in preventing recurrence.

Surgical Techniques — The Right Approach for Each Case

التقنيات الجراحية — الطريقة المناسبة لكل حالة

There are several surgical approaches to pilonidal sinus, each with different recurrence rates, recovery times, and indications. We select the technique based on the size of the disease, number of sinus openings, whether there is active infection, and whether this is a first operation or a recurrence:

Excision with primary closure: The sinuses are excised and the wound is closed directly. Recovery is faster (2-3 weeks), but recurrence rates are higher (10-20%) because the wound is in the midline where the natal cleft is deepest. This technique is appropriate for small, limited disease in patients with shallow natal clefts.

Limberg (rhomboid) flap: After excision, a rhomboid-shaped flap of tissue is rotated to cover the defect, shifting the wound away from the midline. This flattens the natal cleft and moves the scar to one side, reducing hair penetration and improving wound healing. Recurrence rates are significantly lower — 3-5% in most studies. This is our preferred technique for moderate to large pilonidal disease.

Karydakis flap: An asymmetric closure technique that shifts the wound off the midline. The incision is made to one side, and a skin flap is mobilized to cover the excised area. Recurrence rates are comparable to the Limberg flap (4-6%). This technique is particularly useful for extensive or recurrent disease.

Open excision (secondary healing): The sinuses are excised and the wound is left open to heal from the base up. Recovery is slow (6-12 weeks of daily wound care), but recurrence rates are low (5-8%) because all diseased tissue is removed and the wound is not closed under tension. We reserve this approach for acutely infected cases or complex recurrent disease where flap closure is not feasible.

Pilonidal abscess — emergency drainage: An acute pilonidal abscess requires immediate incision and drainage, not definitive excision. We drain the abscess, allow the acute inflammation to settle over 4-6 weeks, and then plan definitive surgery. Operating on acutely infected tissue increases complication and recurrence rates.