The optimal management of perianal abscesses and fistula in children is controversial and differs from therapy recommendations in adults (1–3). In adults, about 90% of all cases with anal abscess and fistula in ano are assessed to have cryptoglandular etiology (4). An anal fistula and an anal abscess may occur alternately at the exact location and are therefore considered two clinical presentations of cryptoglandular infection (4, 5). In contrast, the pediatric disease affects almost exclusively boys, is only infrequently associated with sepsis, and may resolve spontaneously (6–8). While various approaches have been suggested to manage pediatric perianal abscess and fistula in ano, the optimal treatment is not well defined (9). While some authors favor conservative therapy with sitz baths with or without antibiotics (7, 10), others advocate incision and drainage followed by fistulotomy or fistulectomy (11–13). However, there may be a concern that fistula probing in pediatric settings could lead to iatrogenic fistula due to more delicate tissue in children. It is unknown which patients benefit from intensive fistula probing. The aim of this study was to evaluate the efficiency of surgery for perianal abscess in children and identify parameters that predict recurrence.

Clinical characteristics and recommendations for managing pediatric perianal abscess and fistula in ano are heterogeneous in the literature.

This study aimed to identify risk factors for recurrence after surgery for a perianal abscess in children. In the present study, recurrence occurred in 27 out of 103 (26%) patients following surgical management of perianal abscess. Probing for possible fistula during the initial surgery was identified as a positive predictor for treatment success. In contrast, a history of a prior perianal abscess was a risk factor for recurrence.

The recurrence rate following surgery in our study is comparable to other studies in the pediatric population (14, 15) but lower than in the adult population, where recurrence as high as 40% has been described following incision and drainage (14, 15).

Recurrence may occur either as an abscess or a fistula in ano and is caused by persisting infection (4). Search for fistula and fistulotomy during abscess incision, and drainage prevent recurrence in the adult population (16). While there is concern that fistula probing in the pediatric setting may lead to iatrogenic fistula due to more delicate tissue in young individuals, when performed accurately, probing may identify a co-existing fistula as a potential source of recurrence. In our study, fistula probing was a significant predictor of therapy success. Interestingly, we found no difference in fistula probing between primary and recurrent abscesses. Concordantly with the multivariate analysis for therapy failure after surgical treatment which revealed fistula probing as a positive predictor for successful treatment, one can assume that the lack of consequent fistula probing in the recurrent abscess group may be a cause of undetected fistulas and secondary abscess formation. Recurrence was prevented in 16 cases (15%) by fistulotomy in the current study due to probing. This intriguing finding may suggest that the risk of creating an iatrogenic fistula during probing is minor. However, fistula probing in young individuals may be technically challenging, especially in infants. Knowledge of fistula routes is essential for correct probing, and probing must be cautiously performed. A relevant finding from our study was the history of perianal abscess as a risk factor for recurrence. This finding is similar to the adult population (17).

Many studies have reported a tendency for higher recurrence in infants compared to older children (9, 18, 19). In our study, younger age was associated with recurrent disease in univariate analysis but not multivariate analysis. This is in line with other studies, including the largest cohort reported so far by Gong et al. (6, 20). It remains unclear whether this is due to an alternative etiology or insufficient surgery, probably due to an overlooked fistula, especially in infants.

Christison-Lagay et al. report a significant reduction of fistula formation in patients receiving antibiotics (10). In our study cohort, antibiotics before or after surgery were not associated with the recurrence rate. This finding goes with many studies in adults, where antibiotics have not been shown to improve healing time or reduce recurrence rate (7–9, 19). In the present study, microbiological examination revealed the presence of enteric flora on wound swabs to be a risk factor for recurrent disease at univariate analysis but not at multivariate analysis. This is similar to findings in adults, where microbiological examination does not predict outcome and is thus not recommended (21, 22).

Nonetheless, our study demonstrates that probing for fistula could positively influence surgery outcomes for perianal abscesses in the pediatric population. A history of prior perianal abscess increases the recurrence probability following surgical management of perianal abscess in children. Therefore, all recurrent cases are best managed by specialists in colorectal surgery to reduce recurrence risk via cautious probing.

Taken together, the risk of recurrent disease after simple abscess drainage in children, especially in individuals with a history of a perianal abscess, is noteworthy. Therefore, active probing for a fistula is strongly recommended, especially in cases with recurrence. Search for fistula and fistulotomy significantly decreases the risk of recurrence.

This study has several limitations. The main limitation is the retrospective study design. Because the patients in this study were all seen in a hospital setting after surgical referral, it is possible that many perianal abscesses were treated medically without a surgical referral or surgically by the primary care provider using incision and drainage or needle aspiration. Therefore, we would advocate a prospective, randomized study to clarify the role of surgical treatment in this population.