Seminar on Child Sexual Abuse
Ralph C. Underwager
IX. Medical evidence
A. There is an over reliance on the medical examination.
1. Many parents, social workers, investigators, prosecutors, defense attorneys,
therapists, etc. assume that an abused child will show physical signs of the abuse.
2. In most reported cases of child sexual abuse, however, there is no physical or medical
evidence that a child has been sexually abused.
a. Inasmuch as a considerable portion of sexual abuse involves exhibitionism, breast
and/or genital fondling, and masturbation of the perpetrator, this finding is not
b. Therefore, a normal physical exam cannot rule out sexual abuse. B. Uses of a medical
1. A medical examination ought be done whenever it may contribute helpful information if a
report is not immediately dismissed as unfounded.
2. It is particularly important when the allegations are of abusive behaviors that are
likely to result in physical sequelae (i.e., penile penetration of a young child).
3. For example, Paul (1977) reports that penile penetration in young children results in
diffuse and widespread injuries including multiple tears and bruising in the labia,
vaginal walls and hymen. The injury will bleed and the child will experience immediate and
excruciating pain. If an accusation of penetration in a very young child is made and there
is no physical evidence, it is unlikely that the accusation is true.
4. The medical examination must be done as soon as possible since genital injuries heal
rapidly and physical signs will be difficult to detect if the examination is not performed
immediately after the alleged event (Bays & Chadwick, 1993; McCann, Voris, &
5. However, the high level of unquestioning credibility given to what is presented as
medical evidence must be considered in evaluating medical examinations (Krugman, 1989).
C. The results of medical examinations for sexual abuse are frequently ambiguous.
1. Base rate studies of nonabused children indicate that many of the findings often used
to support a diagnosis of abuse are found with a high enough frequency in normals that
they do not support an opinion that abuse occurred (Coleman, 1989; McCann, Voris, Simon,
& Wells, 1989, 1990; McCann, Wells, Simon, & Voris, 1990).
2. Some reported findings, such as lax sphincter tone and the anal dilatation reflex, are
controversial and rejected by many medical authorities.
3. Enlarged vaginal openings
a. Cantwell, in 1983, stated that an enlarged vaginal opening as a single finding
correlates with the reported history of sexual abuse in approximately 75% of 45 cases. She
defined an enlarged opening as one exceeding 4 mm. This assertion is still found in
medical reports we have reviewed.
b. Since that time, baseline studies have shown that this conclusion cannot be supported
(Emans, Woods, Flagg & Freeman, 1987; McCann, Wells, Simon, & Voris, 1990).
c. An examining physician may make statements about the size of the hymenal opening based
on the basis of visual examination alone. The claim of an enlarged opening obtained by
visual examination only is highly questionable.
d. The position the examination is done in will affect the results of the examination
(McCann, Voris, Simon, & Wells, 1990).
e. Paradise (1989) estimates that when the hymenal orifice diameter is used as a screening
test for sexual abuse, there will be 65% false positives for allegations of penile
penetration and 73% for digital penetration.
4. Genital injuries and trauma are often associated with sexual abuse. However, there can
be other causes which must be ruled out.
a. A number of conditions in young girls are associated with prepubertal vaginal bleeding,
including severe vaginal infections and lesions caused by physical activity such as fence
or straddle injuries (Behrman & Vaughan, 1983).
b. Falls onto a pointed object and violent splits can cause injuries to the genital area
of young children and the doctor must consider such an interpretation when looking at
genital injuries (Paul, 1977).
5. Sexually transmitted diseases
a. Sexually abused children have contracted gonorrhea, rectogenital chlamydial infections,
herpes simplex, venereal warts and syphilis Such diseases have been found in the genitals,
rectum and throat.
b. However, only a relatively small percentage of sexually abused children contract these
c. Although it is rare for sexually transmitted diseases to occur in children without
sexual abuse, it can happen. Therefore, a finding of these venereal diseases in children
does not conclusively establish sexual abuse. But further investigation for sexual abuse
is warranted whenever these diseases are found. 6
6. Vaginal discharge and infection.
a. Vaginal discharge and infections often result in suspicion of sexual abuse.
b. However, vaginal infections are not unusual in young girls and constitute the most
common gynecological problems of children and adolescents (Behrman & Vaughan, 1983;
Huffman,1958). Most of these infections are not due to sexual abuse.
c. The premenarchal genitals present a different environment for the growth of bacteria
than do the tissues of adults (Huffman, 1958). The anatomy of the prepubertal vagina lying
close to the anus, lacking the pubic hair and labial fat pads of the older girl in
conjunction with poor hygiene leads to vaginal infections (Behrman & Vaughan, 1983;
7. Redness, irritation, and/or erythema of the vaginal area
a. Paul (1977) notes that the infantile mucosa is normally much redder than that of the
post- pubescent merely because the epithelium is thinner. This redness is not the same as
the more localized redness due to bruising and abrasion that can result from attempted
penetration. Therefore, such redness does not indicate that sexual abuse has probably
b. Excoriation of the skin of the vulval and perineal areas and of the skin around the
natal cleft is sometimes interpreted as evidence of sexual assault. However, such
excoriation is common in small children due to poor local hygiene, the exclusion of the
air by waterproof or nylon panties, or scratching from worm infestations.
c. Sometimes a vulvo-vaginitis of the Monilia type will be found after taking antibiotics
8. Erickson (1985) claims that lax sphincter muscles and enlarged openings in young
children do not indicate abuse inasmuch as penetration by an adult male phallus results
not in stretching and laxness but in tearing, mutilation, and injury.
D. However, there are now enough data on normal and nonabused children to classify many
findings as normal or nonspecific and others as lying on a continuum of certainty that
sexual abuse has occurred (Adams, 1992; Bays & Chadwick, 1993).
E. An invariable finding when there has been anal penetration is that the child will
experience pain on defecation for some time afterwards ( Paul, 1990.)
F. Violent cases of sexual abuse can produce nongenital cuts and bruises (Woodling &
Kossoris, 1981). Sometimes there is abrasion or bruising of the inner surface of the lips,
looseness of the incisor teeth, or even damage to the frenulum of the upper lip in cases
where a very young child has been sexually assaulted. Such injuries accompany the attempts
to muffle the child's screams (Paul, 1977).
G. Controversial medical techniques.
1. Breo (1984) claims evidence of sexual abuse by emotional reactions of children while
undergoing medical examination (insertion of a finger or fingers into the vagina or anus,
noting apparent laxness of sphincter muscles).
2. A Minneapolis pediatrician uses a technique of inserting her finger into the vagina and
anus and stroking the clitoris in order to elicit alleged associations with prior
3. Most responsible physicians resist such examinations, claiming they are medically
dangerous and/or unable to yield valid conclusions (Erickson,1985; Cantwell, 1983;
H. In many instances a medical report claiming to have substantiated abuse has no physical
evidence but is instead based upon the history given to the physician either by a parent
or law enforcement or social work personnel, an interpretation of emotional expressions of
the child, or statements attributed to the child.
1. There is nothing in the training of physicians that qualifies them for expertise in
interpreting emotions or emotional behavior exhibited by a child.
2. When a medical report is based upon data other than observed physiological facts, its
reliability is no greater than the subjective capacities and competence of the person
making the examination.
I. There are no data to support the conclusion that the behavior of the child during the
physical exam can give information about whether the child was abused.
1. Neither unusual fearfulness nor lack of anxiety during the exam should not be used as
evidence for or against abuse.
2. We have read reports using both of these behaviors as evidence of abuse.
J. The only specific and unambiguous physical findings demonstrating sexual contact are
pregnancy or sperm in the vagina or anus (Krugman, 1989). Each report stating an opinion
that a medical examination conclusively substantiates a diagnosis of abuse or rules it out
must be examined carefully. This is especially true of those that do not report any
physical findings but rely upon history or interpretations of emotion or behavior.