The National Center on Child Abuse and Neglect defines child sexual abuse as “A type of maltreatment that refers to the involvement of the child in sexual activity to provide sexual gratification or financial benefit to the perpetrator, including contacts for sexual purposes, molestation, statutory rape, prostitution, pornography, exposure, incest, or other sexually exploitative activities.”¹

Child sexual abuse includes fondling the child’s genitals, getting the child to fondle an adult’s genitals, mouth to genital contact, rubbing an adult’s genitals on the child, or actually penetrating the child’s vagina or anus. Showing an adult’s genitals to a child, showing the child pornographic material, or using the child as a model to make pornographic material are also forms of child sexual abuse.

Sexual abuse of children is a very real problem in our society. Children are most often abused by adults or older children who are known to them and who can exert power over them. The victim knows the offender in 8 out of 10 reported cases. The offender is more frequently male.² The offender is frequently someone that the child trusts and will often persuade the child with bribes, tricks, or coercion to engage in sex or sexual acts. There is often a period of “grooming” during which time the perpetrator gradually develops the child’s trust. This can be followed by threats to the child if he or she tells.

While 57,300 cases were confirmed according to 2015 NCANDS (National Child Abuse and Neglect Data System) data, sexual abuse affects more than 100,000 children each year in the United States.³ Most abuse goes unreported during childhood. However, it is estimated that 20% of girls and 9% of boys are the victims of sexual abuse during childhood.^1,4 Children of all ages are the victims of sexual abuse, but are most likely to be abused sexually during preadolescence—that is, from ages 8 to 12 years.⁴ Increased risk for sexual abuse of children is not related to socioeconomic status.⁴ While racial disparities have been found for other types of child maltreatment, data does not indicate differences for sexual abuse.^3,4

The vast majority of children who are the victims of sexual abuse will have normal examinations without findings of injury. Studies have found that both normal-appearing genital tissues and nonspecific findings are seen in children known to be sexually abused.^5–7 Kellogg et al. found that of 36 adolescents who were pregnant at the time of or shortly before a sexual abuse examination, 22 (62%) had normal or nonspecific examination findings. Only 2 of these 36 girls (6%) had definitive findings consistent with penetration.⁸

There are many factors that contribute to the majority of examinations being normal even in the face of proven sexual abuse. Most sexual abuse of children occurs without the use of physical force and restraint. The perpetrator generally has no intent of harming the child physically, because of a desire to reengage the child in the activities over time. In addition, studies of the healing process of the anogenital area consistently report that most injuries resulting from sexual abuse heal relatively quickly.^8–12 McCann et al. found that the healing of non-hymenal genital injuries in girls was as short as 24 hours for petechiae, 2 days for bruising, 3 days for abrasions, and 5 days for edema.¹² With frequent delays in disclosure of sexual abuse, injuries that may have been present at the time of the abuse will often have healed by the time the child undergoes a physical examination. Further, genital tissues are mucosal tissues that are elastic in nature, well vascularized, and heal quickly without scarring, making the tissues less prone to permanent tissue injury. This point is particularly pertinent to girls who are undergoing pubertal changes with the presence of estrogen that creates thicker and more redundant tissues, particularly thicker and more redundant hymenal tissue. Also of note, the anus can enlarge to large diameters to pass bowel movements and therefore injuries to the anus from penetrating abuse are infrequent.¹³

When a child does have physical injuries from sexual abuse, the findings can involve the genitalia, anus, oral cavity, extragenital sites, or any combination of the above. These injuries might include superficial abrasions, bruises, tearing of the hymen, or deeper genital injury. In prepubertal girls, the most common genital injuries include superficial abrasions of the inner aspects of the labia minora, the periurethral area, and the posterior fourchette.¹³ If an object such as a finger or penis has penetrated through the hymenal orifice, an interruption of the integrity of the hymenal edge may occur. If the hymenal tissue is thought of as the face of a clock (with the child in the supine position), the findings of the hymenal tissue from the 3- to 9-o’clock positions are particularly noteworthy when assessing for injuries from abuse. Interruptions, lacerations, or injuries to the hymenal tissue may extend into the vagina or through the fossa navicularis, and in cases of extreme blunt force trauma, may extend onto the perineum.

Accidental straddle injuries on playground equipment, toys, furniture, etc., often result in physical injuries. The key in discerning such injuries from sexual abuse is that straddle injuries typically include injury to the clitoris, clitoral hood, mons pubis, and labia. Also important to note is that straddle injuries are usually asymmetric and do not involve the hymen.⁴ Conversely, the posterior fourchette, fossa navicularis, and posterior hymen are the structures/areas that are injured with penetrating traumatic events.⁴

Table 144-1 summarizes the 2015 revisions to the 2007 guidelines and approach to interpreting physical and laboratory findings in suspected child abuse developed by a group of physician experts and published by Adams et al. in 2016.¹⁴ Figures 144-1 to 144-7 illustrate a variety of physical examination findings ranging from normal variants to findings diagnostic of trauma.