John Libbey Eurotext

Hépato-Gastro & Oncologie Digestive


Fistulas in-ano with specific bacterial infectious causes Volume 27, issue 10, Décembre 2020


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Institut Léopold Bellan, Groupe hospitalier Paris Saint-Joseph, Service de proctologie médico-chirurgicale, 185, rue Raymond Losserand, 75014 Paris
* Correspondance

Fistula in-ano is a common condition whose aetiology is most often cryptoglandular (infection of Hermann and Defosses glands). Although rare, some infectious causes need to be known because they justify an appropriate antibiotic treatment that can sometimes avoid the use of surgery. This is the case for actinomycosis, tuberculosis, atypical mycobacterial infection and sexually transmitted infections by Chlamydia and Neisseria gonorrhoeae. These diagnoses should be considered when there is an atypical fistula, a recurrent and/or a prolonged progression, unprotected sexual intercourse, or precarious social situations. Actinomycosis is an infection due to an anaerobic Gram positive saprophyte bacterium that may be responsible for fistula in-ano. Microbiological diagnosis is sometimes difficult, but histology can provide arguments by revealing “sulfur granules”.G Penicillin therapy is recommended during 6 to 12 months, according to the duration of healing, in association with surgery. Anal fistula represents a rare location of tuberculosis; it is associated with pulmonary damage in most cases, but isolated forms are possible. The diagnosis is confirmed by the identification of the Koch Bacillus (culture or PCR) or the presence of giant cells in histology. Treatment with anti-tuberculosis therapy for a period of 6 to 12 weeks and then bitherapy for a total duration of 6 months is necessary. Nontuberculosis mycobacteria are even more rare and occur almost exclusively in immunocompromised patient. Lymphogranuloma venereum (LGV) and N. gonorrhoeae are sexually transmitted infections with increasing incidence. The rectal swab with PCR identification confirms the diagnosis. Treatment is based on doxycycline for a duration of 21 days for LGV and the single injection of 3rd generation cephalosporin for N. gonorrhoeae.