Does antibiotic therapy for anal abscess reduce the risk of fistula surgery? A retrospective study

Management of first-time perianal abscesses remains controversial. While the French school of proctology systematically investigates fistulas, other approaches advocate simple incision, given that over 60 % of patients do not develop recurrence. The role of post-incision antibiotic therapy is also debated. This study aimed at evaluating our department's approach to managing first perianal abscesses and identifying predictive factors for recurrence.

We retrospectively included all patients presenting in 2019 with a first perianal abscess treated by incision under local anesthesia, with or without antibiotic therapy post-incision. Patients with evident fistulas underwent surgery. Recurrence was defined as a new abscess or purulent opening. The primary outcome was the rate of patients requiring fistula surgery and/or experiencing abscess recurrence; secondary outcomes included identification of recurrence predictors.

Among the 336 patients who consulted for an abscess, 109 were included. Among 109 patients (mean age 43 ± 13 years; 74 % male), 55 had incision alone, and 54 underwent fistula surgery. The mean follow-up for patients with incision alone was approximately 30 months, during which 18 % (10 patients) experienced abscess recurrence. Univariate logistic regression analysis revealed smoking and absence of antibiotic therapy post-incision as predictive of recurrence with (OR 0.44) were predictive of recurrence. Gender, age, BMI, diabetes, Crohn's disease, HIV infection, prior NSAID use, and abscess location were not predictive. Multivariate analysis was not conducted due to insufficient data.

This study demonstrates that 41 % of patients who underwent incision for a first perianal abscess did not experience recurrence during the follow-up period. Additionally, the administration of antibiotic therapy post-incision was associated with a reduced likelihood of recurrence. However, randomized trials are warranted to validate these findings and specify the optimal antibiotic regimen.