Anorectal Abscess in Children Workup

Updated: Dec 02, 2019
  • Author: Nelson G Rosen, MD, FACS, FAAP; Chief Editor: Robert K Minkes, MD, PhD  more...
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Laboratory Studies

In otherwise healthy babies with anorectal abscess or fistula, no laboratory studies are required. A complete blood count (CBC), culture of perianal abscess drainage, or both may be warranted in some clinical scenarios; however, these studies are not of great utility in focusing therapy and can usually be omitted without risk or detriment to the patient.

Blood counts and cultures should be obtained in all patients with immune compromise from any cause (eg, inflammatory bowel disease, an immune disorder, or malignancy).


CT, Radiography, and MRI

No imaging studies are necessary for the evaluation of otherwise healthy infants with perianal abscess or fistula-in-ano. In older children with a greater likelihood of Crohn disease or in any older child who appears systemically ill, computed tomography (CT) of the pelvis may be required to rule out a deep-space infection.

Referral to a gastroenterologist is recommended in all children with suspected Crohn disease once the abscess has been treated. Studies that may be employed to evaluate for other Crohn disease manifestations include a contrast enema and a small-bowel contrast study.

Magnetic resonance imaging (MRI) may be useful for delineating the anatomy of a fistula or deep abscess, especially in children with Crohn disease.


Other Studies

Colonoscopy with biopsy may be needed to confirm Crohn disease. Endoscopy is not required in otherwise routine cases.

No histologic analysis is required in the routine treatment of perianal abscess and fistula. Biopsy may be performed in older children with a chronic fistula to evaluate for granulomas as a sign of Crohn disease.