PEDIATRIC DERMATOLOGY Series Editor: Camila K. Janniger, MD Childhood Warts: An Update Supriya G. Bellew, MD; Nicole Quartarolo, MD; Camila K. Janniger, MD Warts are benign intraepidermal neoplasms that pinpoint, flesh-colored papules. Over weeks to months, are caused by infection with human papillo- they enlarge into yellow, black, or brown papules mavirus and commonly affect children and ado- with a rough papillomatous surface. Common warts lescents. The 4 most common types of cutaneous range from a single lesion to multiple coalescing warts are common warts, plantar warts, flat lesions. Periungual warts, particularly common in warts, and genital warts. Although they rarely individuals with habitual nail biting or cuticle pose a serious health problem, warts can result manipulation, often become irritated or infected. in physical impairment and psychosocial dis- Incomplete treatment or irritation may lead to comfort. A variety of treatment modalities are autoinoculation and the development of satellite employed to treat these growths in children. lesions surrounding the original wart. Digitate and Cutis. 2004;73:379-384. filiform warts, variants of common warts, tend to occur on the face and scalp, presenting as single or multiple spikes protruding from the skin surface. arts are benign intraepidermal tumors that The diagnosis of common warts can be easily con- arise on both skin and mucosal surfaces firmed by gently paring the lesion with a 15 blade W and occur commonly in children. Warts to reveal characteristic black dots, which represent affect approximately 10% of children and adoles- thrombosed capillaries. cents, with the peak incidence occurring between Plantar warts occur on the plantar surfaces of the ages of 9 and 16 years.1-3 The 4 most common the weight-bearing regions of the toes, mid- types of cutaneous warts are the common wart (ver- metatarsals, and heels. The constant, repetitive ruca vulgaris), plantar wart (verruca plantaris), flat pressure induced by ambulation often causes the wart (verruca plana), and genital wart (condyloma warts to become very deep-seated and painful. acuminatum). Although these lesions rarely pose a Plantar warts may be multiple, with the develop- serious health problem, they can result in signifi- ment of smaller satellite lesions. The term mosaic cant physical impairment and psychosocial discom- warts refers to multiple, contiguous plantar warts fort. Many treatment modalities are used to treat fusing to form a thick keratotic plaque. The differ- warts in children, but no particular treatment is ential diagnosis of plantar warts includes calluses, universally efficacious. Thus, warts continue to corns, and talon noir (black heel). However, paring pose a therapeutic challenge. with a 15 blade may be done to differentiate plan- tar warts from these lesions. Clinical Manifestations Flat warts occur most commonly on the face, Common warts occur most frequently on the dorsal neck, and extremities. They present as flat-topped aspect of the hands (favoring the fingers and peri- smooth papules ranging from 2 to 5 mm in diameter ungual region) and on the palms (Figure 1). They and are flesh-colored, erythematous to brown, or can, however, occur anywhere on the body and on hyperpigmented (Figure 2). Two to several hundred mucosal surfaces. Typically, they begin as discrete, lesions may develop. Shaving, especially in the beard area in men and legs in women, leads to autoinoculation and subsequent spread of lesions. A Accepted for publication February 3, 2004. linear array of lesions, due to the Köbner phe- From Dermatology, UMDNJ-New Jersey Medical School, Newark. The authors report no conflict of interest. nomenon, is characteristic. At times, flat warts Reprints: Camila K. Janniger, MD, Dermatology, New Jersey Medical may resemble other lesions. Hyperpigmented flat School, 185 S Orange Ave, MSB H-576, Newark, NJ 07103-2714. warts may be mistaken for lentigines or ephelides. VOLUME 73, JUNE 2004 379 Childhood Warts Plaques of coalescing flat warts must be differenti- ated from lichen planus and molluscum contagiosum. In addition, erythematous flat warts on the face may be confused with papular acne vulgaris. Genital warts occur as exophytic growths affect- ing the vulva, vagina, cervix, penis, urethra, or perianal region. They present as soft, lobulated, flesh-colored papules or nodules, which may be peduncular or polypoid (Figure 3). The differential diagnosis for genital warts includes condylomata lata of secondary syphilis, which present as wide- based moist papules or nodules. Multiple genital warts may coalesce, forming large cauliflowerlike masses in moist occluded regions such as the peri- anal skin, vulva, and inguinal creases. In these cases, genital warts must be differentiated from giant condyloma acuminatum (Buschke-Lowenstein tumor), a type of verrucous carcinoma. Genital warts in children may be transmitted by sexual contact, autoinoculation from warts on other areas Figure 1. Common wart with smaller satellite lesion on of the body, vertical transmission perinatally, the dorsal aspect of the hand. fomes, or social contact. In children younger than 1 year, vertical transmission is probable. The risk of genital warts as a marker for sexual abuse is higher in children older than 3 years. However, all chil- dren with genital warts should undergo a thorough evaluation to rule out sexual transmission and, therefore, sexual abuse. Diagnosis Warts are generally diagnosed clinically; the lesion may be pared with a 15 blade, as described previ- ously, to confirm the diagnosis. In addition, warts can be distinguished by the lack of skin lines cross- ing their surface. When the diagnosis is unclear or the lesions are refractory to medical treatment, biopsy or surgical removal may be performed. His- tologically, common and plantar warts demonstrate papillomatosis, epidermal hyperkeratosis with tiers of parakeratosis, and acanthosis. The rete ridges are elongated and are often bent inward at the periph- ery, pointing to the center of the lesion. Large vac- uolated cells, termed koilocytes, in the upper malpighian stratum and granular layer are charac- teristic. The dermal papillae are elongated and thin with prominent blood vessels. Verruca plana demonstrates hyperkeratosis and acanthosis but lacks papillomatosis and parakeratosis. In genital warts, the stratum corneum exhibits only slight thickening, with mucosal lesions showing paraker- atosis. The epidermis shows papillomatosis, signifi- cant acanthosis, and elongated rete ridges. Mitotic figures are sometimes present. Areas with epithelial cell perinuclear vacuolization in the deeper layers Figure 2. Numerous flat warts, some in a linear array of the malpighian stratum are characteristic. demonstrating Köbner phenomenon. 380 CUTIS® Childhood Warts Figure 3. Multiple coalescing genital warts in a young girl. Pathogenesis normal functioning. Symptoms are particularly Warts are caused by infection with the human prevalent with plantar warts, which, if located on papillomavirus (HPV), a double-stranded DNA pressure points, can interfere with ambulation. papovavirus. More than 100 types of HPV have Although warts may resolve spontaneously, they been reported, with each type having a predilec- often persist, with the potential to spread to adjacent tion for certain body sites. HPV types are differen- or distant sites in the body.4 tiated by the type of epithelium they infect and the No single specific treatment is indicated for all malignant potential they exhibit. Common warts types of warts, and the many available treatments are most commonly linked with HPV-2, -4, and -7, are less than ideal. Many of the treatments are plantar warts with HPV-1 and -2, and flat warts nonspecific or require multiple visits to the practi- with HPV-3 and -10. HPV-6 and -11 have tradi- tioner. Because two thirds of warts will regress tionally been associated with condylomata acumi- spontaneously within 2 years, physicians are often nata (anogenital warts), whereas HPV-16, -18, -31, unsure how aggressive therapy should be.8 Many -33, and -35 have been associated with the devel- clinicians are reluctant to treat verrucae at all, opment of cervical intraepithelial neoplasia and especially in children. Unfortunately, it is impossi- cervical squamous cell carcinoma (Table 1).4-7 ble to predict which wart will involute; therefore, HPV enters the host through a break in the epi- by not treating, a physician may be performing a dermis, and autoinoculation is common. The precise disservice to the patient. Further, warts can cause mechanism by which a cell becomes infected with significant cosmetic and psychosocial damage in the virus remains an enigma. Clinically detectable children and adolescents. In addition, because warts emerge a few weeks to 18 months after inocu- warts may spread to other body sites, there is addi- lation; however, in most individuals, the virus is car- tional rationale for the initiation of early interven- ried without generating any noticeable lesions. The tion. Since there is no single effective treatment, quantity of viral particles in a particular verruca has the least painful therapy should take priority when been correlated with the risk of transmission. Thus, dealing with children. the reduction of infectious virions within a verruca Conventional methods of treatment nonspecifi- has been shown to decrease the risk of spread to cally destroy infected tissue. These methods include other sites or to others.4 cryosurgery; excision;