<prompt> Urinary retention in child is most commonly caused byMetal scab with ulcerationPosturethral valveUrethral strictureEpispadius  <response>: A Metal scab with ulceration Acute urinary retention in a male child may be due to local inflammatory causes like meatal ulcer with scabbing. Etiology of Urinary Retention in Children: Neurological processes Severe voiding dysfunction UTI Constipation Adverse drug effect Local inflammatory causes Locally invading neoplasms Benign obstructing lesions Idiopathic Combined UTI and Constipation Incarcerated Inguinal Hernia. 