Natural course of perianal abscess in infants: a real-world study.

Natural course of perianal abscess (PA) in infancy remains obscure. This study aimed to investigate the natural course of infants with PA after conservative treatment. A retrospective cohort study was conducted in infants with PA who were treated conservatively (due to the parents' refusal of surgery), for more than 2 months between 2014 and 2020 at a single tertiary center. 153 patients (149 boys and 4 girls) were identified. The median follow-up was 5.3 years (range 3-8.2 years). Initially, 119 patients (77.8%) were completely cured by conservative treatment, and 34 (22.2%) failed. Among the 34 patients, 23 continued conservative treatment (20 cure, 3 fistula formation) and 11 underwent surgery. After conservative treatment, the rate of fistula formation, abscess recurrence, and new-onset abscess were 15.0%, 4.6%, and 6.5%, respectively. Overall, 139 patients (90.8%) were cured conservatively without surgery, and 11 (7.2%) underwent surgical management. In addition, 3 (2.0%) patients developed fistula-in-ano (under observation). PA in infants may be a time-limited and self-limited condition. Conservative management should be the first choice of treatment in most cases. Longer periods of conservative treatment may achieve better clinical outcomes in selected cases. There will be a percentage of patients (about 10%) that would require surgical treatment.