Irritant contact dermatitis is a common cause of genital eruptions representing at least one-fifth of presenting anogenital symptoms. A spectrum of inflammatory reactions have been identified, some of them with features severely mimicking more serious dermatoses, which may lead unnecessary workup and treatments. We report a case of a 10-year-old girl who presented at birth with cloacal atresia involving the rectum and the urethra. A diverting colostomy and a urethral-vaginal fistula were created to correct the deformity. Physical examination reveals numerous shiny, white-gray, pseudoverrucous papules and nodules coalescing into plaques over the vulva and its surrounding skin. Histological examination showed psoriasiform epidermal hyperplasia with a marked reactive acanthosis and altered cornification with parakeratosis, hypogranulosis, and pale keratinocytes in the upper reaches of the epidermis. The lesions regress when the irritating factor was removed. This case represents a peculiar form of presentation of perianal pseudoverrucous papules and nodules, usually secondary to urinary incontinence or encopresis (inability to control the elimination of stool) after surgery for Hirschsprung disease. Because similar findings have not been previously observed in patients with urethral-vaginal fistula, we attempt to extend the spectrum of presentations for a better knowledge of this condition.