Reflex anal dilatation: An observational study on non-abused children.

Objectives: Reflex anal dilatation (RAD) is considered as a possible sign of anal abuse,however studies evaluating its prevalence in non-abused children are limited. The aim of this study was to evaluate the prevalence of RAD in a convenience sample of children with no suspicion of abuse admitted to a Pediatric Emergency Department (PED).
Methods: Prospective observational study including children admitted to the PED of Padova, Italy, between January and June 2011. Patients with no suspicion of abuse and for whom ano-genital examination was part of their medical evaluation were included. Children were excluded if in critical clinical conditions or if any suspicion of abuse arose during medical evaluation. Presence/absence of RAD and of factors favoring its appearance were recorded for each patient.
Results: Two-hundred and thirty children (median age of 12 months, interquartile range 5-35 months) were finally included. A positive RAD was reported in 14 (6.1%, CI 95% 3.4-10). Only 3 patients (1.3%, CI 95% 0.3-3.7) showed a positive RAD in the absence of any predisposing factor.
Conclusions: RAD is an infrequent sign in non-abused children and it is particularly rare in the absence of any predisposing factor. Case-control studies are necessary to better clarify its diagnostic relevance.
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