Natural course of cutaneous warts among primary schoolchildren: a prospective cohort study.

Purpose: Because cutaneous warts resolve spontaneously and available treatments often fail, family physicians and patients may consider a wait-and-see policy. We examined the natural course of cutaneous warts and treatment decisions in a prospective observational cohort of primary schoolchildren.

Methods: We inspected the hands and feet of children aged 4 to 12 years from 3 Dutch primary schools for the presence of warts at baseline and after a mean follow-up of 15 months. Parental questionnaires at follow-up provided information on inconvenience caused by warts and any treatments used.

Results: Of the 1,134 eligible children, 1,099 (97%) participated, of whom 366 (33%) had cutaneous warts at baseline. Among these children with warts, loss to follow-up was 9% and the response rate to the parental questionnaires was 83%. The complete resolution rate was 52 per 100 person-years at risk (95% CI, 44-60). Younger age (hazard ratio = 1.1 per year decrease; 95% CI, 1.0-1.2) and non-Caucasian skin type (hazard ratio = 2.0; 95% CI, 1.3-2.9) increased the likelihood of resolution. During follow-up, 38% of children with warts at baseline treated their warts: 18% used over-the-counter treatment only, 15% used a family physician-provided treatment only, and 5% used both. Children were more likely to initiate treatment if the warts measured at least 1 cm in diameter (odds ratio = 3.2; 95% CI, 1.9-5.3) and especially if parents reported that the warts caused inconvenience (odds ratio = 38; 95% CI, 16-90).

Conclusions: One-half of primary schoolchildren with warts will be free of warts within 1 year. Young age and non-Caucasian skin type enhance resolution. Children with large or inconvenient warts are more likely to start treatment. These findings will be useful in the process of shared decision making with parents and children.