Communal showers and the risk of plantar warts

Background. Plantar warts occur most commonly in adolescents and are more prevalent among users of public locker rooms. Previous studies have not differentiated shower rooms from locker rooms as risk factors.

Methods. The current study examined the prevalence of plantar warts among a group of 146 adolescents who used locker rooms. Subjects ranged in age from 10 to 18 years and were recruited from a public school and a swim club. All subjects used public locker rooms but only those in the swim club used communal showers on a regular basis. All subjects were interviewed by a physician and underwent an examination of the feet.

Results. There was a statistically significant difference in the prevalence of plantar warts between the shower room users (27%) and those who used only locker rooms (1.25%).

Conclusions. The present study suggests that public shower users are at greater risk for plantar warts than are locker room users who do not use communal showers.

Key words. Warts; prevalence; swimming; public facilities; foot. (J Fam Pract 1995; 40:136-138)

The prevalence of nongenital warts in the general population has been estimated at 7% to 10%[1,2] According to the literature, nongenital warts afflict females more than males, are most common in adolescents, and rarely afflict the elderly.[3] The tendency of individuals to seek medical treatment for the relief of pain associated with plantar warts suggests that they are the most annoying of the nongenital warts. Recent studies have found a higher incidence of plantar warts among athletes and users of public swimming pools.[4,5] These studies have suggested that the locker room environment may be a risk factor for users of public facilities. The current study was conducted to determine whether the risk of plantar warts is higher among individuals who use public showers than among those who use only locker rooms.

Plantar warts (verrucae plantaris) are usually causcd by typc I human papillomavirus (HPV), although type 4 has bcen isolatcd from some mosaic plantar warts. Thc vir,us enters a compromiscd skin surface through direct contact and attacks the granulosum and keratin layers of thc epidcrmis.[6] Inoculation depends on the degree of skin integrity as well as individual susceptibility.[7] Type 1 HPV has been noted to have the highest viral particle density of any of the HPV genotypes, an important factor in the transmission of plantar warts.[8]

A study of plantar warts in more than 13,000 school-aged children in East Anglia, United Kingdom, reported a prevalence of 6.5 per 1000, with a peak incidence at age 13 for...