Risk of rosacea in patients with diabetes using insulin or oral antidiabetic drugs.

study from Detroit, Michigan, found that warts were more commonly diagnosed in Caucasians (22.6%) than in African Americans (5.7%) (Henderson et al., 2012). A previous study of the determinants of sexually transmitted infections found that Caucasians were more likely than African Americans to have venereal warts (Short et al., 1984). Furthermore, a recent prevalence study of warts in Caucasian Dutch schoolchildren aged 4–12 years showed that one-third of the children had warts (van Haalen et al., 2009). This suggests that the incidence described in the United States may actually be lower than that in other countries owing to the mixture of racial and ethnic groups in our population. The strengths of this study include being a large-scale, US population– based survey with minimal selection bias, and controlling for confounding demographic variables in multivariate models. However, the study also has some limitations. Warts and comorbidities were assessed by caregiver report, which have not been fully validated. The appearance of common warts is reasonably characteristic, and lay recognition can be assumed to be good. Another concern about self/parentalreported warts is potential reporting bias, where subjects with higher socioeconomic status may have better overall health and be more motivated to seek out care for warts. Future studies are needed to validate the accuracy of self/ caregiver report and determine the ideal survey instrument for the epidemiologic study of these disorders. The peak age of warts occurring at 9–10 years and common presence in teenagers may relate to school attendance and exposures from peer groups. Schooland family-based transmissions have been cited as a leading cause of disease (van Haalen et al., 2009). Agespecific physical activity and sports participation, particularly swimming pool use (Penso-Assathiany et al., 1999) and use of communal showers (Johnson, 1995), have been linked to transmission of warts. Racial/ethnic and socioeconomic disparities may affect age-specific activities and pool use. Future studies are warranted to determine the role of age-specific physical activities and local environment on the US prevalence of warts.