Perianal abscess and fistula-in-ano in children: clinical characteristic, management and outcome.

Purpose: The aims of this study are to evaluate the clinical characteristics of perianal abscess and fistula-in-ano in children, and to assess our experience in treatment, and to identify factors that affected the clinical outcomes.

Methods: A retrospective review of children with perianal abscess and fistula-in-ano was carried out in a tertiary care children's hospital from January 2005 to December 2010. Demographic information of the patients, localization of the lesions, treatment procedures, microbial organisms in pus, usage of antibiotics, abscess recurrence, development of fistula-in-ano, and duration of symptoms were recorded. Patients with systemic diseases and inflammatory bowel diseases were excluded from the study.

Results: A total of 158 children (146 males, 12 females) treated for perianal abscess and fistula-in-ano with a median age of 7.2 months (ranging 16 days to 18 years) were eligible for the study. Initial examination of the 136 patients revealed perianal abscess and 22 patients with fistula-in-ano. Primary treatment was incision and drainage (I/D) for the fluctuating perianal abscess (73.5%), and local care for the spontaneously (S/D) drained abscess (26.5%) with or without antibiotic therapy. Patients were divided into two groups according to age distribution, 98 of the patients were younger than 12 months, and 60 were older than 12 months of age. There was no significant difference in sex distribution, localization of the lesions, treatment procedures, recurrence of abscess and fistula-in-ano formation between the two age groups (p > 0.05). Recurrence rates (27% in I/D and 30.6% in S/D, p > 0.05) and development of fistula-in-ano (20% in I/D and 27.8 in S/D, p > 0.05) were not significant I/D and S/D groups. Kind of the microorganisms in pus swaps did not effect the fistula-in-ano formation. Usage of antibiotics significantly reduced the development of fistula-in-ano (p = 0.001), but did not effect the recurrence of perianal abscess (p > 0.05). The mean follow-up period was 10.6 ± 8.6 months. While the 9 of the overall 52 fistula-in-ano (22 initial, 30 after abscess treatment) were resolved spontaneously, 43 of the remaining needed surgical intervention (fistulotomy/fistulectomy).

Conclusions: Although management of perianal abscess is still controversial, simple drainage of the perianal abscess with additional antibiotic therapy reduces the development of fistula-in-ano. Fistula-in-ano within children has a chance of spontaneous resolution thus the immediate surgical intervention should be avoided.