Pilonidal abscesses typically occur at the superior aspect of the gluteal fold and are more common in teenage and young adult males. Patients present with pain, swelling, and drainage, but usually do not have systemic symptoms. They are thought to occur when bacteria enter the hair follicle and cause edema that obstructs the opening to the skin surface. Eventually the follicle may rupture, which allows spread into the subcutaneous fatty tissue and abscess formation. Acute abscesses typically contain mixed organisms, including Staphylococcus aureus and Streptococcus species. Anaerobes and gram-negative organisms may also be present. Cellulitis in the sacrococcygeal area may result from a simple abscess or furuncle. Consider alternative causes such as anal fistulae, hidradenitis, inflammatory bowel disease, or tuberculosis.
Pilonidal Abscess. Redness, fluctuance, and tenderness in the gluteal cleft seen with a pilonidal abscess. (Photo contributor: Louis La Vopa, MD.)
Management and Disposition
An acutely fluctuant abscess requires incision and drainage under local anesthesia. Instruct the patient on careful wound care and sitz baths. Antibiotic therapy is indicated in immunocompromised patients or those with significant surrounding cellulitis or systemic symptoms. Pilonidal abscesses have a high recurrence rate. Refer chronic or recurrent cases to a surgeon for evaluation for operative management.
Pilonidal Abscess. Close-up of the cutaneous manifestations of a large pilonidal abscess. (Photo contributor: Lawrence B. Stack, MD.)
Pilonidal abscesses almost always occur in the midline but can have sinus tracts extending off the midline.
Pilonidal disease is three times more common in men than in women.
Pilonidal Abscess with Cellulitis. Middle-aged male with recurrent pilonidal abscess and surrounding cellulitis. (Photo contributor: Lawrence B. Stack, MD.)