Case 18

Proper diagnosis of anogenital warts is important. Differentiation of warts due to sexual abuse versus warts due to maternal or household transmission can often be determined based on clinical information. In this case, the age of the child (less than 3 years), maternal history of an abnormal Pap smear, and the provided non-suspicious psychosocial history lead to the diagnosis of probable maternal transmission of human papillomavirus (HPV). Further evaluation for risk factors for sexual abuse as well as infection with other sexually transmitted infections is warranted. However, the most likely diagnosis in this case is HPV due to maternal transmission in the perinatal period. In this case, the physician may also consider advising the mother to return to her doctor for further evaluation for HPV.

There are more than 130 types of DNA viruses, members of the Papillomaviridae family that may result in HPV infections and warts. In general, typing of the warts is not recommended for forensic purposes.

HPV is very common and it is estimated that at least 50% of sexually active men and women acquire genital HPV at some point in their lives. It is considered to be the most common STI, infecting more than 40% of sexually active teens. Anogenital infections are usually subclinical and transmitted by sexual contact.

The pathogenesis of HPV in infants and children includes vertical transmission from maternal sources, non-sexual transmission from household contact and sexual contact. Vertical transmission via placenta, birth canal and post-neonatal caregiving are possible modes of transmission.

The risk factors for infection with HPV include: sexual abuse, maternal HPV, maternal abnormal Pap smear, subclinical oral HPV (maternal or other), diaper changes with transmission of non-genital HPV types to genital surface (e.g., hand to genital transmission), possible fomite transmission in households with HPV, host immunosuppression and skin abnormalities or skin conditions that predispose to this viral infection.

Estimates for perinatal transmission range between 8 months to several years. However, there have been reports with identification of these warts at birth. The incubation period varies depending on host immune response, virus type and clinical appearance of the lesions. HPV DNA in infants born to infected mothers ranges from 1%-77%. However, a similar range has been shown to be present in infants of uninfected mothers, further suggesting the ubiquity of this infection.

Many HPV warts regress within a few months of an outbreak and many physicians prefer to observe for this regression with watchful waiting. Warts may also persist without increasing proliferation. Treatment with immunosuppressive agents, such as imiquimod, has been shown to be successful. Other treatments, such as laser, liquid nitrogen and podophylin, have been utilized. With or without treatment, recurrences of clinical warts are common.

Condylomata acuminata, the clinical manifestation of HPV on the skin or mucosal surfaces, typically have a cauliflower-like appearance and are usually skin-colored or hyperpigmented. The appearance may be keratotic on skin but is generally non-keratinized on mucosal surfaces. This photo demonstrates dome-shaped, smooth papules that are skin colored. In other areas, the papules may be flatter, particularly if seen on the cervix. Keratotic warts have a thick, sometimes yellowed, horny surface. HPV infections in infants and children may present as laryngeal papillomatosis, also called juvenile onset recurrent respiratory papillomatosis (JORRP).

The differential diagnosis of these lesions includes the following:

• Pink pearly penile papules
• Vestibular papillae (micropapillomatosis labialis)
• Skin tags (acrochordons)
• Acquired dermatologic conditions
• Seborrheic keratosis
• Lichen planus
• Fibroepithelial polyp or adenoma
• Melanocytic nevus
• Neoplastic lesions
• Condyloma lata tend to be smoother, moist, more rounded, and darkfield-positive for Treponema pallidum (the infectious etiology for syphilis).
• Molluscum contagiosum, papules with central dimple caused by a pox virus, rarely involves mucosal surfaces.*

Note that irritation from pinworms or irritation due to poor hygiene should not be confused with these papules. The pruritis in this case was likely unrelated to the genital warts but may have been due to irritation of the area.

Further Reading

• * CDC Page on Molluscum Contagiosum
• CDC Page on Human Papillomavirus (HPV)