Genital lacerations may occur following sexual assault or after accidental or self-inflicted trauma. Dermatologic conditions causing pruritus can also lead to minor lacerations, abrasions, and excoriations. Acute lacerations or extensive bruising of the labia, perihymenal tissues, penis, scrotum, or perineum are considered moderate specificity of abuse. Injury to the genital area in children always gives cause for concern. Parents are often worried about permanent damage and are concerned about sexual abuse.
Accidental injuries to the genitalia usually have a clear history, with findings on examination consistent with that history. Straddle injuries are a type of accidental trauma that lead to compression of the soft tissues of the vulva, scrotum, or penis between the object and the pubic ramus, causing bruising, abrasions, and/or lacerations. In a typical straddle injury, one foot slips and the child falls forward, compressing the genital area (eg, on the monkey bars). This causes anteriorly placed abrasions and asymmetric bruising of the genitalia. Scraping of the medial side of one thigh may also occur, especially if the object straddled has a rough surface (eg, on the side of a swimming pool). Associated lacerations, if present, are most often superficial. In girls, the hymen is protected by the vulva and, therefore, should not be injured. Impaling injury (eg, from a picket fence) may lead to hymenal trauma, usually with a corresponding clear history.
Stretch injuries, “the splits,” can result in superficial lacerations in the skin of the perineum or fourchette, especially if there were preexistent labial adhesions.
Severe self-inflicted injury is unlikely because of the pain caused by self-trauma. Minor abrasions may occur if children scratch because of vulvovaginitis or pinworm infection. Rarely do these conditions lead to severe lacerations.
Children with genital lacerations typically complain of genital pain, soreness, and sometimes dysuria when the urine passes over the exposed area. The urethral meatus may also have lacerations, erythema, and discharge. The external genitalia of boys must also be evaluated for lacerations and abrasions possibly due to bite injury and associated erythema and ecchymosis.
Perineal irritation and erythema with associated abrasions are most likely due to excoriation secondary to pruritus associated with contact dermatitis (often caused by diapers), seborrheic dermatitis, poor hygiene, and candidiasis. Excoriations rarely lead to severe lacerations and most often present as minor abrasions.
Because positive physical findings of sexual abuse occur infrequently, one cannot overemphasize that the history from the child still remains the single most important diagnostic feature in assessing whether a child has been sexually abused.