Perianal abscess and fistula in ano in infancy and childhood: a clinicopathological study.

This is a retrospective study of 78 children with perianal abscess and/or fistula in ano presenting during a 6 1/2-year period. Sixty-five were males and 13 females. Their ages at presentation ranged from 22 days to 18 years (median 1.7 year), and the majority of males were below 2 years of age. The 13 females all presented with perianal abscess, the majority of which grew Staphylococcus aureus (69.2%). On follow-up, none of them developed fistula in ano. Twenty-two of the 65 males (33.8%) presented initially with fistula in ano. The remaining 43 presented with perianal abscess. Four of them were found to have fistula in ano at the time of incision and drainage and on follow-up, and 14 others developed fistula in ano. Of the 40 cases of fistula in ano, all were males; 25 were on the right side and 9 on the left side, 5 had bilateral fistula in ano, and 1 had two fistulas on the left side at 3 and 5 o'clock positions. Gut-derived organisms were isolated from 88.4% of the males with perianal abscess. There appears to be a causal relationship between perianal abscess and fistula in ano.