A 42-year-old man comes to the office due to increasing anal pain. Three days ago, he noticed mild anal discomfort when wiping after a bowel movement; since then, the pain has steadily increased and is now constant and severe. The patient has had no anal drainage, hematochezia, or melena. Medical history includes hypertension and type 2 diabetes mellitus. There is no family history of colon cancer. Temperature is 38.3 C (100.9 F), blood pressure is 122/74 mm Hg, and pulse is 90/min. Examination shows an erythematous, tender, 2-cm mass external to the anal verge on the right. Digital rectal examination is normal, and stool guaiac testing is negative. Incision and drainage are performed under local anesthesia, yielding approximately 5 mL of purulent fluid. Which of the following is the best next step in management of this patient?

Question

A 42-year-old man comes to the office due to increasing anal pain.  Three days ago, he noticed mild anal discomfort when wiping after a bowel movement; since then, the pain has steadily increased and is now constant and severe.  The patient has had no anal drainage, hematochezia, or melena.  Medical history includes hypertension and type 2 diabetes mellitus.  There is no family history of colon cancer.  Temperature is 38.3 C (100.9 F), blood pressure is 122/74 mm Hg, and pulse is 90/min.  Examination shows an erythematous, tender, 2-cm mass external to the anal verge on the right.  Digital rectal examination is normal, and stool guaiac testing is negative.  Incision and drainage are performed under local anesthesia, yielding approximately 5 mL of purulent fluid.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: This patient with a perianal abscess has undergone incision and drainage and should now receive systemic antibiotic therapy to decrease the risk of abscess recurrence and fistula formation. Anorectal (ie, perianal, perirectal) abscesses arise when an anal crypt gland becomes obstructed, allowing bacterial overgrowth. Initially the obstruction may cause only mild symptoms (eg, discomfort when wiping), but as bacteria and white blood cells (ie, purulent fluid) collect and expand (eg, distally into the perianal skin), severe anal pain and systemic symptoms (eg, fever) may develop. On physical examination, a superficial abscess usually appears as an erythematous, tender mass, often with fluctuance, in the perianal skin. Primary treatment is prompt incision and drainage to prevent continued abscess expansion into adjacent spaces (eg, ischiorectal space). Following drainage, systemic antibiotic therapy is indicated for: patients with systemic illness (eg, fever) or cellulitis patients with increased risk of severe infection (eg, diabetes, immunosuppression). In these patients, antibiotic therapy decreases abscess recurrence. In addition, antibiotic therapy may decrease the odds of anorectal fistula formation, a common (up to 50%) complication of anorectal abscess; therefore, antibiotic therapy should be considered for every patient following abscess drainage (Choice C). (Choice A) Colonoscopy may be indicated to screen for colorectal cancer (eg, age ≥50, strong familial history) or to visualize the colon when symptoms suggest colonic disease (eg, hematochezia suggestive of lower gastrointestinal bleeding, progressive diarrhea in inflammatory bowel disease). This patient has none of these indications. (Choice B) CT scan of the abdomen and pelvis can help visualize deep (eg, ischiorectal, supralevator) anorectal abscesses but is not necessary for superficial abscesses that can be visualized (eg, erythematous mass in the perianal skin) on physical examination. (Choice D) Perianal disease (eg, abscess, fistula) can be the initial manifestation of Crohn disease in a minority (~10%) of patients. Nevertheless, perianal abscesses in Crohn disease are treated with incision, drainage, and antibiotics to eradicate infection prior to the initiation of corticosteroids (eg, oral prednisone) or other medical therapies that affect the immune system. Educational objective: Occlusion of an anal crypt gland can lead to the formation of an anorectal abscess. Primary treatment is prompt incision and drainage. Systemic antibiotic therapy, which may decrease recurrence and anorectal fistula formation, should be given to patients with high-risk features (eg, systemic illness, diabetes) and considered for all patients. References: Antibiotic use in prevention of anal fistulas following incision and drainage of anorectal abscesses: a systematic review and meta-analysis. (http://www.ncbi.nlm.nih.gov/pubmed/30773213) Clinical practice guideline for the management of anorectal abscess, fistula-in-ano, and rectovaginal fistula. (http://www.ncbi.nlm.nih.gov/pubmed/27824697)

A 42-Year-Old Man Comes to the Office Due to Increasing