acquired sinus tracts may form external to the postsacral fascia Pilonidal abscess is not to be confused with perirectal abscess, which may need urgent surgical consultation due to invasion of deeper structures Patients with pilonidal abscess typically complain of low back pain, increased on sitting, and local tenderness On examination, a tender, indurated swelling is noted overlying the sacrococcygeal area with the original sinus at its cephalad end ( Fig 120.22 ) Treatment consists of incision and drainage with careful probing to break up loculations and extract any hairs present because these act as foreign bodies Incision should be lateral to the intergluteal cleft due to inferior healing of midline wounds Cultures usually grow mixed organisms, including staphylococci, anaerobes, and fecal flora Home care includes improved hygiene and sitz baths Oral antimicrobial therapy should be considered if there is overlying cellulitis, incomplete drainage, immunodeficiency, or high-risk patient medical history Elective excision of the entire cyst and all associated sinus tracts by a surgeon is indicated once inflammation has resolved Local reoccurrence is high after both local incision and drainage and elective excision FIGURE 120.22 Infected pilonidal cyst (Courtesy of Scott Van Duzer, MD In: Chung EK, Boom JA, Datto GA, et al., eds Visual Diagnosis in Pediatrics Philadelphia, PA: Lippincott Williams & Wilkins; 2006 With permission.) Cutaneous Manifestations of Spinal Dysraphism