21 - Pediatric Gynecologic Disorders

prepubertal girls more sensitive to a variety of chemical, physical, and microbiologic irritants. The normal hymen looks thin, with an average opening of about 4 mm. However, there is great variability in normal hymenal shape, ranging from imperforate to multiple small fenestrations to oval, round, or stellate openings (Fig. 21.1). Abnormal findings that may correlate with vaginal penetration include lacerations of the hymen or a thickened hymen with rolled edges. These findings are extremely difficult to differentiate from normal variations, and photos should always be taken if sexual abuse is suspected. Neonates have swollen labia and thick, moist vaginal epithelium for several weeks after birth, but most prepubertal girls have smooth pink vaginal mucosa and a pale vulva that barely covers the clitoris.