Prevalence of acquired melanocytic naevi in Brazilian schoolchildren

Visual scales are superior to questionnaires in skin phototype self-assessment by children

BACKGROUND/PURPOSE

There are no suitable methods for skin phototype self-assessment by children. Our study investigated several skin phototype self-assessment methods in children to identify the best correlation to objectively measure skin phototype.

METHODS

Danish schoolchildren (ages 6-19) participated in a nation-wide study that assessed skin, eye, hair colour and sun behaviour. Skin phototype self-assessment was performed by children using two visual colour scales (cartoon faces and colour cards), question-based colour scale and questions about tendency to burn and ability to tan. For objective skin phototype measurements, 483 children from all age groups were selected and their pigment protection factor (PPF) was measured at three skin sites using a skin reflectance spectrophotometer.

RESULTS

Cartoon faces (r²  = 0.654) and colour cards (r²  = 0.659) were better at predicting PPF on the inner forearm than the question-based colour method (r²  = 0.520). PPF prediction from questions on skin reaction to sun exposure was markedly inferior (r²  ≤ 0.142) to both visual colour scales and question-based colour method.

CONCLUSION

Both visual colour scales proved to be superior to question-based skin phototype self-assessment in schoolchildren. In contrast, questions on skin reaction to sun exposure were shown to be an unsuitable tool for self-assessment of skin phototype in children.

Clinical and dermoscopic patterns of melanocytic nevi in Hispanic adolescents: a descriptive study

BACKGROUND

Melanocytic nevi are well-known, important precursors of melanoma among children and adults. The adolescence period is an important period for nevi formation and evolution. This study provides data of a longitudinal study of nevi in a Hispanic adolescent population.

MATERIALS AND METHODS

A cross-sectional survey and 1-year prospective follow-up study was performed on Hispanic students from grades 6 and 7 at a school in Caguas, Puerto Rico (n = 90). The survey was completed by the students and one of their parents. The backs of the children were clinically examined for melanocytic nevi using digital photography and dermoscopy. Follow-up was conducted one year later.

RESULTS

The study cohort consisted of 53 (59%) boys and 37 (41%) girls, with an average age of 11.9 years (range 11-13 years). At the beginning of the study, 85% (n = 71/90) of the students presented with melanocytic nevi on their backs. After one year, new nevi were identified in 62% (n = 44/71), and there was a mean increase in nevus count of 1.8 (P < 0.001). A trend toward increased nevus count in lighter skin types was observed (P < 0.001). The predominant dermoscopic pattern was reticular (44%). The globular pattern was found most commonly in children with skin-type II (100%), while the reticular pattern was the most common among skin-types III (32%), IV (56%), and V (45%).

CONCLUSIONS

This study supports the utility of digital photography and dermoscopy for the evaluation of melanocytic nevi, providing evidence of the interrelationship between nevus count, dermoscopic pattern, and skin phenotype.

Constitutive and relative facultative skin pigmentation among Victorian children including comparison of two visual skin charts for determining constitutive melanin density

Our aim was to examine the association between ethnicity, phenotype, sun behavior and other characteristics, and constitutive and relative facultative skin pigmentation. A total of 191 participants were recruited, with a mean age of 7.6 years (SD 3.4), during 2009-2011 from Maternal and Child Health Centres (MCHC) and schools in Melbourne, Australia. Parental questionnaire data were obtained on sun behavior and examination consisted of noting the child's natural skin, hair and eye color, ethnicity, nevi count and spectrophotometric melanin density (MD). Constitutive skin pigmentation was estimated from buttock MD. Relative facultative skin pigmentation was estimated by hand compared with buttock absorption. Ethnicity, hair color and skin color were associated with constitutive and facultative skin pigmentation on univariate analysis. Higher ambient ultraviolet radiation (UVR) in the past month, greater freckling, greater nevi and increased sun exposure over the past year were related to darker facultative skin pigmentation. Sun exposure over the life course was not. The two skin charts accounted for 39.7% and 21.4% of buttock MD, respectively. Relative facultative skin pigmentation is associated with recent UVR levels, not life-course sun exposure. Relative facultative skin pigmentation may not be a useful measure of sun exposure over the early life course. Skin color charts can be used to assess constitutive skin pigmentation if spectrophotometry is not available.

The challenges of UV-induced immunomodulation for children's health

Exposure to solar ultraviolet radiation (UVR) is recognised to have both beneficial and harmful effects on human health. With regard to immune responses, it can lead to suppression of immunity and to the synthesis of vitamin D, a hormone that can alter both innate and adaptive immunity. The consequences in children of such UV-induced changes are considerable: first there are positive outcomes including protection against some photoallergic (for example polymorphic light eruption) and T cell-mediated autoimmune diseases (for example multiple sclerosis) and asthma, and secondly there are negative outcomes including an increased risk of skin cancer (squamous cell carcinoma, basal cell carcinoma and cutaneous malignant melanoma) and less effective control of several infectious diseases. Many uncertainties remain regarding the amount of sun exposure that would provide children with the most effective responses against the variety of immunological challenges that they are likely to experience.

The human health effects of ozone depletion and interactions with climate change

Depletion of the stratospheric ozone layer has led to increased solar UV-B radiation (280-315 nm) at the surface of the Earth. This change is likely to have had an impact on human exposure to UV-B radiation with consequential detrimental and beneficial effects on health, although behavioural changes in society over the past 60 years or so with regard to sun exposure are of considerable importance. The present report concentrates on information published since our previous report in 2007. The adverse effects of UV radiation are primarily on the eye and the skin. While solar UV radiation is a recognised risk factor for some types of cataract and for pterygium, the evidence is less strong, although increasing, for ocular melanoma, and is equivocal at present for age-related macular degeneration. For the skin, the most common harmful outcome is skin cancer, including melanoma and the non-melanoma skin cancers, basal cell carcinoma and squamous cell carcinoma. The incidence of all three of these tumours has risen significantly over the past five decades, particularly in people with fair skin, and is projected to continue to increase, thus posing a significant world-wide health burden. Overexposure to the sun is the major identified environmental risk factor in skin cancer, in association with various genetic risk factors and immune effects. Suppression of some aspects of immunity follows exposure to UV radiation and the consequences of this modulation for the immune control of infectious diseases, for vaccination and for tumours, are additional concerns. In a common sun allergy (polymorphic light eruption), there is an imbalance in the immune response to UV radiation, resulting in a sun-evoked rash. The major health benefit of exposure to solar UV-B radiation is the production of vitamin D. Vitamin D plays a crucial role in bone metabolism and is also implicated in protection against a wide range of diseases. Although there is some evidence supporting protective effects for a range of internal cancers, this is not yet conclusive, but strongest for colorectal cancer, at present. A role for vitamin D in protection against several autoimmune diseases has been studied, with the most convincing results to date for multiple sclerosis. Vitamin D is starting to be assessed for its protective properties against several infectious and coronary diseases. Current methods for protecting the eye and the skin from the adverse effects of solar UV radiation are evaluated, including seeking shade, wearing protective clothing and sunglasses, and using sunscreens. Newer possibilities are considered such as creams that repair UV-induced DNA damage, and substances applied topically to the skin or eaten in the diet that protect against some of the detrimental effects of sun exposure. It is difficult to provide easily understandable public health messages regarding "safe" sun exposure, so that the positive effects of vitamin D production are balanced against the negative effects of excessive exposure. The international response to ozone depletion has included the development and deployment of replacement technologies and chemicals. To date, limited evidence suggests that substitutes for the ozone-depleting substances do not have significant effects on human health. In addition to stratospheric ozone depletion, climate change is predicted to affect human health, and potential interactions between these two parameters are considered. These include altering the risk of developing skin tumours, infectious diseases and various skin diseases, in addition to altering the efficiency by which pathogenic microorganisms are inactivated in the environment.

Sun-induced changes in stratum corneum function are gender and dose dependent in a Chinese population

Previous studies have demonstrated that UVB radiation changes the epidermal permeability barrier and stratum corneum (SC) hydration. It is well known that sun exposure causes erythema, sunburn and melanoma. However, whether daily sun exposure alters SC integrity and epidermal permeability barrier function is largely unknown, especially in Chinese subjects. In the present study, we assess the SC integrity, SC hydration and epidermal permeability barrier function following various doses of sun exposure. A total of 258 subjects (124 males and 134 females) aged 18-50 years were enrolled. A multifunctional skin physiology monitor (Courage & Khazaka MPA5) was used to measure SC hydration and transepidermal water loss (TEWL) on the forearms. In males, basal TEWL was higher with higher doses of sun exposure than with lower doses and control, whereas in females, basal TEWL was higher with lower doses of sun exposure than with higher doses and control. In the group with higher doses of sun exposure, TEWL in females was significantly lower than that in males. The barrier recovery was faster in females than in males in both control and lower-dose groups. In both males and females, barrier recovery was delayed with higher doses of sun exposure. In males, sun exposure did not alter SC hydration, while in females SC hydration was lower with lower doses of sun exposure as compared with control and higher doses of sun exposure. These results demonstrated that sun-induced changes in SC function and SC hydration vary with gender and the extent of sun exposure.