HPV type-specific distribution among family members and linen in households of cutaneous wart patients.

BACKGROUND: Common and plantar warts are caused by human papillomaviruses (HPV). Mode of transmission of wart HPVs within families is largely unknown. OBJECTIVE: To demonstrate similarity of HPV type(s) among wart cases, family members and household linen. METHODS: In a cross-sectional study, swabs taken from 123 warts and foreheads of 62 index patients and 157 family members and from 58 kitchen towels and 59 bathroom mats were tested for DNA of 23 cutaneous wart-associated HPV types. Generalized estimating equations (GEE) were used to estimate the chance of detecting the same HPV type as was found in the index patients on the family contacts and on the kitchen towels and bathroom mats. RESULTS: HPV1, HPV2, HPV27 and HPV57 were the most prevalent types in the warts of the index patients. Altogether, 60 (42.3%) of the 142 family members without warts had HPV DNA on their foreheads. When HPV1 and HPV2 were found in the warts, these types were also frequently (>50%) found on the foreheads of index patients and their family members, as well as on the kitchen towels and the bathroom mats. HPV27 and HPV57 were less frequently found (<25%) on foreheads and linen. No associations were found for age, sex and site of HPV DNA presence. CONCLUSION: Dissemination of skin wart-causing HPV types, from wart cases to household contacts and linen, such as kitchen towels and bathroom mats, is more likely for HPV1 and HPV2 than for HPV27 and HPV57. The role of towels and bathroom mats in HPV transmission deserves further investigation.

Developing and validating the Cutaneous WARTS (CWARTS) diagnostic tool: a novel clinical assessment and classification system for cutaneous warts.

BACKGROUND: The clinical appearance of cutaneous warts is highly variable and not standardized. OBJECTIVES: To develop and validate a reproducible clinical tool for the standardized assessment of cutaneous warts to distinguish these lesions accurately. METHODS: Nine morphological characteristics were defined and validated regarding intra- and interobserver agreement. Based on literature and semistructured interviews, a systematic dichotomous assessment tool, the Cutaneous WARTS (CWARTS) diagnostic tool was developed. The validation consisted of two independent parts performed with photographs from the recent WARTS-2 trial. In part A, the CWARTS diagnostic tool was tested by 28 experienced physicians who assessed photographs of 10 different warts to investigate interobserver concordance. In part B, morphological characteristics were validated by masked and independent scoring of 299 photographs by six different observers. Part B also entailed reassessment of the photographs after at least 1 week. The primary outcome measurement was the intraclass correlation coefficient (ICC). RESULTS: Presence of black dots (capillary thrombosis) had the greatest ICC (0·85) for interobserver agreement in part A, followed by arrangement (0·65), presence of border erythema (0·64) and sharpness of the border (0·60). In part B, results were similar for interobserver agreement with presence of black dots having the highest ICC (0·68), followed by border erythema (0·64), arrangement (0·58) and colour (0·55). For intraobserver agreement, presence of black dots had the highest agreement (0·70), followed by presence of border erythema (0·694) and colour (0·59). CONCLUSIONS: Wart phenotype can be reliably assessed using the CWARTS diagnostic tool.

Morphological characteristics and human papillomavirus genotype predict the treatment response in cutaneous warts.

BACKGROUND: Cutaneous warts have a cure rate after therapy of no more than approximately 50%. Recently, we developed and validated a standard assessment tool for warts (Cutaneous WARTS diagnostic tool, CWARTS) based on phenotypical characteristics. OBJECTIVES: To assess whether patient and morphological wart characteristics predict the human papillomavirus (HPV) type in a specific wart and whether these characteristics as well as the HPV type predict a favourable treatment response. METHODS: Photographs were used to score nine morphological wart characteristics using the newly developed CWARTS tool. Genotyping of 23 wart-associated HPV types was performed using the hyperkeratotic skin lesion-polymerase chain reaction/multiplex genotyping assay. The results were correlated with a favourable response to treatment with monochloroacetic acid, cryotherapy or a combination of cryotherapy and salicylic acid. Odds ratios were calculated using logistic regression in a generalized estimating equations model. RESULTS: Black dots (capillary thrombosis) strongly predicted the presence of any HPV type in a wart. From all characteristics tested, the HPV type most strongly predicted the treatment response when the warts were treated with monochloroacetic acid or a combination of cryotherapy and salicylic acid with a significantly decreased treatment response if the warts contained HPVs of the alpha genus (HPV2, HPV27 or HPV57). When cryotherapy alone was used for common warts, HPV type did not play a role, but cryotherapy was less effective in the presence of callus and when the wart was located deeper in the skin. CONCLUSIONS: Morphological characteristics of the warts and the HPV genotype influence treatment outcome and thus potentially influence future treatment decisions for common and plantar warts.

High prevalence of cutaneous warts in elementary school children and the ubiquitous presence of wart-associated human papillomavirus on clinically normal skin.

BACKGROUND: One-third of Dutch primary school children have cutaneous warts; each year around 20% of them seek medical treatment. However, little is known about the epidemiology of the types of human papillomavirus (HPV) causing these warts. OBJECTIVES: To investigate the distribution of cutaneous wart-associated HPV types in three primary school classes by analysing skin swabs taken from warts, and the forehead, hand dorsum and sole of the foot of included children. METHODS: Using the hyperkeratotic skin lesion polymerase chain reaction/multiplex genotyping assay, each swab sample was used to genotype for 23 cutaneous wart-associated HPV types. RESULTS: Thirty-one (44%) of the 71 children had a total of 69 warts, with a maximum of six warts per child. In the wart swabs, HPV2, HPV27 and HPV57, members of Alphapapillomavirus species 4, were most frequently detected (27%, 32% and 14%, respectively), whereas HPV1 was only found in two plantar warts. The prevalence of HPV carriage, detected in swabs of clinically normal skin of the forehead, left hand and left sole was 80%, with the most prevalent types being HPV1 (59%), HPV2 (42%), HPV63 (25%) and HPV27 (21%). CONCLUSIONS: Cutaneous wart-associated HPV types were highly prevalent in primary school children, but did not correlate with the HPV types in warts. In contrast to the existing literature, HPV1 was frequently detected on clinically normal skin but was much less frequent in warts.

Warts in primary schoolchildren: prevalence and relation with environmental factors.

BACKGROUND: Warts are very common in primary schoolchildren. However, knowledge on wart epidemiology and causes of wart transmission is scarce. OBJECTIVES: To determine the prevalence of warts in primary schoolchildren and to examine the relation with environmental factors in order to provide direction for well-founded recommendations on wart prevention. METHODS: In this cross-sectional study, the hands and feet of 1465 children aged 4-12 years from four Dutch primary schools were examined for the presence of warts. In addition, the children's parents completed a questionnaire about possible environmental risk factors for warts. RESULTS: Thirty-three per cent of primary schoolchildren had warts (participation rate 96%). Nine per cent had hand warts, 20% had plantar warts and 4% had both hand and plantar warts. Parental questionnaires (response rate 76%) showed that environmental factors connected to barefoot activities, public showers or swimming pool visits were not related to the presence of warts. An increased risk of the presence of warts was found in children with a family member with warts [odds ratio (OR) 1.9, 95% confidence interval (CI) 1.3-2.6] and in children where there was a high prevalence of warts in the school class (OR per 10% increase in wart prevalence in school class 1.6, 95% CI 1.5-1.8). CONCLUSIONS: One-third of primary schoolchildren have warts. This study does not find support for generally accepted wart prevention recommendations, such as wearing protective footwear in communal showers and swimming pool changing areas. Rather, recommendations should focus on ways to limit the transmission of wart viruses within families and school classes.