Infectious Diseases Perspective of Anorectal Abscess and Fistula-in-ano Disease

Anorectal abscess and fistula-in-ano is a rare disease with an exemplary prognosis. Most patients are diagnosed with cryptoglandular disease but unusual infections raise difficult antimicrobial management challenges.All primary references identified in PubMed, EMBASE, the ISI Web of Knowledge database and the Cochrane Library, published between 1960 and 2015, using the keywords "anorectal abscess," "fistula-in-ano," "perianal abscess," or "perianal fistula" or all, were uploaded into a database. The databases were also interrogated using keywords specific for each infection type studied.In all, 52 relevant primary medical publications were identified. There were also 4 relevant organizational standards guideline publications, 1 relevant review and 4 historical publications about the diagnosis and outcomes of anorectal abscess and fistula-in-ano with data derived primarily from prospective and retrospective trials as well as institutional case series to provide an evidence level opinion. The use of antimicrobial therapy in combination with surgical incision and drainage in the treatment of cryptoglandular disease has failed to improved healing times or reduce recurrences or both. Based on limited data, routine antimicrobial therapy may benefit patients with significant comorbid conditions, extensive cellulitis and systemic symptoms. For patients with unusual infecting pathogens (eg, Mycobacterium tuberculosis, Actinomyces species and Chlamydia species) outcomes are favorable with selected antimicrobial therapy agents of various durations.Surgical incision and drainage is the main treatment for anorectal abscess and fistula-in-ano, but a select group of patients with unusual infections benefit from tailored prolonged antimicrobial therapy with the overall recurrence rate remaining low.