Should a patient with a small perirectal abscess and persistent serous drainage after 10 days of Keflex (Cephalexin) receive another round of antibiotics or be referred for surgical evaluation?

From the Guidelines

For a small perirectal abscess with persistent serous drainage after 10 days of Keflex, I recommend referring the patient to surgery for evaluation rather than prescribing another round of antibiotics. Perirectal abscesses typically require surgical drainage as the primary treatment, as antibiotics alone are often insufficient to resolve the infection completely, as suggested by the guidelines from the World Journal of Emergency Surgery 1. The continued drainage suggests that the abscess may not have adequately drained or that there could be an underlying fistula that needs assessment. A colorectal surgeon or general surgeon can perform an examination to determine if incision and drainage is needed, or if there are complications such as a fistula-in-ano that require surgical intervention. Key points to consider in management include:

• The primary treatment of anorectal abscesses remains surgical drainage, with the timing being dictated by the severity and nature of any sepsis 1.
• In patients with drained anorectal abscess, antibiotics administration is suggested in the presence of sepsis and/or surrounding soft tissue infection or in case of disturbances of the immune response 1.
• The role of wound packing after anorectal abscess drainage remains unproven, and its use should be left to individual unit policy and patient discussion 1. While waiting for the surgical consultation, the patient should be advised to maintain good perianal hygiene with warm sitz baths 2-3 times daily and gentle cleansing after bowel movements. Antibiotics alone are generally not curative for perirectal abscesses because they cannot adequately penetrate the abscess cavity, and continued antibiotic use without proper drainage may lead to antibiotic resistance or mask worsening infection. It is also important to consider the risk of recurrence after drainage, which can be as high as 44%, and the associated risk factors, such as inadequate drainage, loculations, horseshoe-type abscess, and time from disease onset to incision 1.

From the Research

Management of Perirectal Abscess

• The patient has a small perirectal abscess and has been treated with Keflex for 10 days, but still has some serous drainage.
• The decision to do another round of antibiotics or refer to surgery for evaluation depends on various factors, including the severity of the abscess, the patient's overall health, and the presence of any underlying conditions.

Evidence from Studies

• A systematic review and meta-analysis published in 2019 2 found that the use of systemic antibiotics for skin and soft tissue abscesses after incision and drainage resulted in an increased rate of clinical cure.
• Another study published in 2009 3 compared the efficacy and safety of sequential intravenous/oral moxifloxacin vs intravenous/oral amoxicillin/clavulanate for complicated skin and skin structure infections, and found that both treatments had similar clinical success rates.
• A review of perioperative antibiotics in clean-contaminated head and neck surgery published in 2020 4 found that cefazolin, ampicillin-sulbactam, and amoxicillin-clavulanate were the most efficient agents in preventing surgical site infections.
• A comprehensive review of antibiotic prophylaxis in surgery published in 2023 5 highlighted the importance of judicious antibiotic stewardship and the need for innovative strategies to enhance surgical site infection prevention.
• A study on the optimal use of surgical drains published in 2018 6 found that closed-suction drains can be optimized by increasing intracavitary tubing length, decreasing extracavitary tubing length, and using perforated drains.

Considerations for Treatment

• The patient's ongoing serous drainage despite 10 days of antibiotic treatment suggests that the abscess may not be fully resolved.
• The decision to continue or change antibiotic treatment should be based on the patient's clinical response and the results of any diagnostic tests, such as imaging or culture results.
• Referral to surgery for evaluation may be necessary if the abscess is large, complex, or not responding to antibiotic treatment.