German S3 guideline: anal abscess.

Background: The incidence of anal abscess is relatively high, and the condition is most common in young men.

Methods: A systematic review of the literature was undertaken.

Results: This abscess usually originates in the proctodeal glands of the intersphincteric space. A distinction is made between subanodermal, intersphincteric, ischioanal, and supralevator abscesses. The patient history and clinical examination are diagnostically sufficient to establish the indication for surgery. Further examinations (endosonography, MRI) should be considered in recurrent abscesses or supralevator abscesses. The timing of the surgical intervention is primarily determined by the patient's symptoms, and acute abscess is generally an indication for emergency treatment. Anal abscesses are treated surgically. The type of access (transrectal or perianal) depends on the abscess location. The goal of surgery is thorough drainage of the focus of infection while preserving the sphincter muscles. The wound should be rinsed regularly (using tap water). The use of local antiseptics is associated with a risk of cytotoxicity. Antibiotic treatment is only necessary in exceptional cases. Intraoperative fistula exploration should be conducted with extreme care if at all; no requirement to detect fistula should be imposed. The risk of abscess recurrence or secondary fistula formation is low overall, but they can result from insufficient drainage. Primary fistulotomy should only be performed in case of superficial fistulas and by experienced surgeons. In case of unclear findings or high fistulas, repair should take place in a second procedure.

Conclusion: In this clinical S3 guideline, instructions for diagnosis and treatment of anal abscess are described for the first time in Germany.