Rationale:

• Genital injury is common after sexual assault.
• Rarely, the severity of the injury may mandate emergent specialist referral for repair.
• Documentation of genital injury may aid in legal diagnosis.
• The colposcope provides magnification, a bright light source, and usually permanent documentation in the form of slides, pictures, or video.
• Photo or video documentation allows for earliest documentation of injuries which heal very quickly and provides for expert practitioner review for court testimony without subjecting the patient to reexamination and the potential loss of evidence if injuries have healed by the time of second examination.
• Genital examination using colposcopy is limited by the fact that almost half of all patients who have been raped lack visible injuries; therefore, a totally normal genital examination by colposcopy is consistent with the diagnosis of sexual assault.
• Additionally, genital injuries detected by colposcopy may be seen after consensual intercourse in some populations.
• Toluidine blue dye is a nuclear stain that adheres to areas of injury (subepithelial nucleated cells) but not to intact epithelized cells; it can enhance the examiner's ability to visualize genital injuries on the perineum and perianal area, but it is not useful on mucosal surfaces such at the vagina or anal mucosa.

Evidence:

• Twenty percent of patients in one large case series of 819 female patients sustained anogenital injury that was visible using routine examination without colposcopy (23).
• Using colposcopy, forensic nurse examiners documented genital injury (lacerations, edema, erythema, ecchymosis, and petechiae) in 53% of 521 female sexual assault victims over age 13 in a retrospective analysis of data from Baltimore's Sexual Assault Response Team program (30).
• In a case series of 44 female patients, the use of toluidine blue dye increased the injury detection rate from 16% to 40% without the use of colposcopy (31).
• Injuries detected with the aid of toluidine blue dye are not 100% specific for sexual assault. A small case series of 50 adolescents found that an equal incidence of toluidine blue dye detected injuries after consensual intercourse and sexual assault (32).
• Another case series of 51 sexually inexperienced teenagers found anogenital injuries in 73% of females after consensual sexual intercourse using colposcopy (33).
• One study showed in the laboratory that the use of toluidine blue dye does not interfere with recovery of DNA evidence (34).
• In one case series of 17 female sexual assault patients, use of the colposcope increased the rate of genital injury detection from 6% (with gross inspection alone) to 53% (35).
• In a case series of 67 male patients, the use of anoscopy and colposcopy provided superior documentation of injuries over gross visualization alone and increased the injury detection rate from 61% to 72% (36).
• In one consecutive case review of 204 sexually inexperienced adolescents after reported penile-vaginal penetration, 68% of patients lacked discernible genital injury using colposcopic examination (37).
• Investigators in an observational multicenter convenience sample of sexual assault images from first examination and follow-up found that genital injuries in adolescent females (and children) most often heal within days of first detection (38).

Comments:

• None.