Anal fistulas and abscess in Crohn disease

This picture shows anterior perianal fistulas involving the vulva and anterior perineum (arrows) in a woman with Crohn disease being prepared for surgery. The surrounding skin is erythematous and indurated. An abscess (arrowhead) appears as a localized swelling. Hypertrophic skin tags (dashed arrows) in the anal canal are commonly observed in perianal Crohn disease and may be confused with external hemorrhoids.