Causes

Unintentional injury can be due to pressure or crush damage as in the common straddle injury but also sharp penetrating injury and bites [2,3]. The majority of accidental injuries in children are falls in a straddle position often involving a gymnastic bar or bicycle. In a case series, 70% of genital injuries in children were straddle injuries, 23.5% blunt injuries, and only 6% penetrating injuries [4]. Skating accidents in can result in deep fissures of the perineum due to rapid adduction of the thighs [5], but penetrative injury is also described in this sport [6]. Rope swing injury can lead to laceration and avulsion of the labia with haematoma formation [7]. Vaginal injury from insufflation in water sports is also described [8]. Rarely, there may be tears of the fourchette in the neonate after breech delivery [9].

Although not an acute injury, prolonged cycling can result in oedema of the labia majora, often unilateral, and has mainly been described in adults (see Chapter 54). One case is reported in an adolescent [10]. See Table 52.1.

Clinical features

The labia majora and minora are most commonly involved as the soft tissue is compressed against the pubic symphysis and rami. There is swelling and bruising and haematoma formation if severe. The hymen and posterior fourchette are rarely involved in straddle injury, but deep posterior fissures can result after rapid adduction injury. In penetrating injuries, laceration and abrasions are usually evident, as well as bruising.