Protection against solar ultraviolet radiation in childhood

In the last decade, awareness of the harmful effects of solar ultraviolet radiation has increased. Modern lifestyles, outdoor occupations, sports and other activities make total sun avoidance impossible. Children spend more time outdoors than adults and there is compelling evidence that childhood is a particularly vulnerable time for the photocarcinogenic effects of the sun. Sun exposure among infants and pre-school age children is largely depend on the discretion of adult care providers. It is important to learn safe habits about sun-safety behaviours during the childhood. Children deserve to live and play in safe environments, and it is the responsibility of every adult to help children stay safe. Protecting children from excessive sun exposure is protection from sunburn today and other forms of sun damages, especially skin cancers, in the future.     

UV radiation: what we know and do we protect ourselves adequately?

Chronic sun exposure causes degenerative changes in the skin that are recognized as photoaging, immunosuppression and photocarcinogenesis. Sun is necessary for life, so total sun avoidance is impossible. Sun exposure during the first 15 years of life and blistering sunburns before age 20 have been linked to an increased risk of melanoma. Individuals who have outdoor lifestyles, live in sunny climates, and are lightly pigmented will experience the greatest degree of photoaging. In our study, performed four years ago, we have shown the knowledge of more than 4000 people about the effects of UV rays on the skin. The results show us that sun exposure is still exaggerated and uncontrolled due to the lack of knowledge about this topic. Encouraging photoprotection and improving the awareness of the general public about the harmful effects of too much sun exposure must be the leading preventative health strategy.     

Acquired melanocytic nevi as risk factor for melanoma development. A comprehensive review of epidemiological data

Acquired melanocytic nevi (MN) in Caucasian populations are important markers for the risk of melanoma development. The total number of MN on the whole body is the most important independent risk factor for melanoma and the risk of melanoma development increases almost linearly with rising numbers of MN. Additionally, the presence of atypical MN and of actinic lentigines are likewise independent risk factors for melanoma. Atypical mole syndrome should be defined by the presence of many acquired MN and a threshold number of atypical MN. Acquired MN develops mainly during childhood and adolescence in the first two decades of life. The number of acquired nevi seems to be related to hereditary factors and nevus-prone families exist. The amount of sun exposure is the most important environmental risk factor for nevus development, particularly in early childhood. Interestingly, sunburns may play a role in nevus development, but seem not to be required, and even moderate sun exposure promotes the process. Therefore, preventive measures for nevus and melanoma development should target young children and adolescents.     

Reviews on sun exposure and artificial light and melanoma

Melanoma is the most common form of cancer among young adults aged 25-29 years and the second most common cancer in those aged 15-29 years. We reviewed all the evidence regarding risk factors for melanoma, looking in particular at childhood exposure to ultraviolet radiation (UV). UV radiation is clearly the predominant environmental and thus potentially modifiable risk factor for melanoma. All activities related to tan-seeking behaviour and history of sunburns were shown to be significantly associated to melanoma. Host factors, such as pigmentary characteristics, and genetic predisposition plays also an important role. UV exposure is not only due to the sun but also to indoor tanning devices that have been shown to lead to an elevated risk of melanoma. The strongest evidence for a link between artificial UV and melanoma is found among individuals who had their first exposure to indoor tanning before the age of 30: they have a 75% increase risk of developing melanoma than individuals who had no exposure to indoor tanning. Prevention is very important, especially for children and young adults, as childhood and adolescence are critical periods in the development of later melanoma. Indoor tanning is a widespread practice in most developed countries, particularly in Northern Europe and the USA. In the recent decades more and more people, especially teenagers and women, are exposed to substantially high radiant exposures of UV through artificial sources and these trends raised a considerable concern. In fact the International Agency for Research on Cancer concluded that the association between skin cancer and exposure to solar radiation and the use of UV-emitting tanning devices are causal. Interesting analyses carried out in Iceland showed that when interventions to discourage sunbed use were introduced the incidence of melanoma among women decreased. All this evidence encouraged many countries to introduce regulations on sunbed use to avoid exposure before the age of 18.     

Influence of age,gender, educational level and self-estimation of skin type on sun exposure habits and readiness to increase sun protection

Background: Sun exposure habits and the propensity to undertake sun protection differ between individuals. Not least in primary prevention of skin cancer, aiming at reducing ultraviolet (UV) exposure, knowledge about these factors may be of importance. The aim of the present study was to investigate, in a primary health care (PHC) population, the relationship between sun exposure habits/sun protection behaviour/readiness to increase sun protection and gender, age, educational level and skin UV-sensitivity. Methods: The baseline data from a previously performed RCT on skin cancer prevention was used. 415 patients, aged >18 years, visiting a PHC centre in southern Sweden, filled-out a questionnaire mapping sun exposure, readiness to increase sun protection according to the Transtheoretical Model of Behaviour Change (TTM), and the above mentioned factors. Results: Female gender was associated with more frequent suntanning (p < 0.001) and sunbed use (p < 0.05), but also with more extensive sunscreen use (p < 0.001). High age was in general associated with low level of sun exposure and high level of protection. Subjects with low educational level reported less frequent sunscreen use than those with higher educational level, and also chose lower SPF (p < 0.001). For almost all parameters, high skin UV-sensitivity was associated with markedly lower sun exposure (p < 0.001) and more pronounced readiness to increase sun protection. Females and subjects with high educational level reported higher readiness to increase sunscreen use than males and subjects with lower educational level (p < 0.001). Conclusions: Gender, age, educational level and skin type appear to be important factors affecting sun exposure habits and sun protection behaviour, which supports the idea of appropriate mapping of these factors in patients in order to individualise sun protection advice according to the individual patient situation and capabilities.     

Long-Term Outcomes Associated with Traumatic Brain Injury in Childhood and Adolescence: A Nationwide Swedish Cohort Study of a Wide Range of Medical and Social Outcomes

BackgroundTraumatic brain injury (TBI) is the leading cause of disability and mortality in children and young adults worldwide. It remains unclear, however, how TBI in childhood and adolescence is associated with adult mortality, psychiatric morbidity, and social outcomes.ConclusionsGiven our findings, which indicate potentially causal effects between TBI exposure in childhood and later impairments across a range of health and social outcomes, age-sensitive clinical guidelines should be considered and preventive strategies should be targeted at children and adolescents.     

New option in photoprotection

All the people are exposed to solar ultraviolet radiation. Exposure to sun with living in an oxygen-rich atmosphere causes unwanted photodemage. Sunburned skin is a leading risk factor for melanoma and non-melanoma cancers. UV exposure causes immunosuppression via multiple mechanisms in the skin. In this review the main topic is to mention new or alternative ways of photoprotection. Sunscreens are commonly used as protection against sun damage. They reduce the penetration of damaging solar UV wavelengths in skin by reflecting or absorbing them. Sunscreens are very valuable, but they have limitations. They have to be used properly to gain the full effect (application a little while before UV exposure, at frequent time points and in adequate amounts). Also, they have the problem of photoinactivation, which is the degeneration of the UV-filter due to exposure to UV rays resulting in the loss of absorbing capacity. Products with immune protection factor contain DNA-repair enzymes and antioxidants that may reduce mutations and enable the immune system to combat photodamage. The use of antioxidants and polyphenols may exert an anti-aging effect by preventing and even reversing sun damage. Adequate photoprotection is essential to control photocarcinogenesis and photoaging.     

Past exposure to sun,skin phenotype,and risk of multiple sclerosis: case-control study

Objective To examine whether past high sun exposure is associated with a reduced risk of multiple sclerosis.Design Population based case-control study.Setting Tasmania, latitudes 41-3°S.Participants 136 cases with multiple sclerosis and 272 controls randomly drawn from the community and matched on sex and year of birth.Main outcome measure Multiple sclerosis defined by both clinical and magnetic resonance imaging criteria.Results Higher sun exposure when aged 6-15 years (average 2-3 hours or more a day in summer during weekends and holidays) was associated with a decreased risk of multiple sclerosis (adjusted odds ratio 0.31, 95% confidence interval 0.16 to 0.59). Higher exposure in winter seemed more important than higher exposure in summer. Greater actinic damage was also independently associated with a decreased risk of multiple sclerosis (0.32, 0.11 to 0.88 for grades 4-6 disease). A dose-response relation was observed between multiple sclerosis and decreasing sun exposure when aged 6-15 years and with actinic damage.Conclusion Higher sun exposure during childhood and early adolescence is associated with a reduced risk of multiple sclerosis. Insufficient ultraviolet radiation may therefore influence the development of multiple sclerosis.     

Childhood exposure to ultraviolet radiation and harmful skin effects: epidemiological evidence

We review the general amount and patterns of exposure to solar ultraviolet (UV) radiation that children and teenagers experience and the spectrum of UV-related skin damage that can occur as a result. Data about the amount of solar UV received by children and teenagers are relatively few but suggest that around 40–50% of total UV to age 60 occurs before age 20. Among white children, those with the palest complexions suffer the most damage. Comparisons of prevalence and incidence of outcomes in children and teenagers sharing common ancestry, but living at different latitudes, show that prevalence rates of photoaging and melanocytic naevi are higher in Australian compared with British children, and similarly for melanoma. Genetic risk for the majority of the melanomas in teens is a function of genes controlling naevus propensity and pigmentation in the skin. High numbers of naevi and freckles, red hair, blue eyes, inability to tan, as well as a family history are the primary determinants of melanoma among adolescents. Beyond the signs of skin damage seen in children are the latent effects observed later in adulthood. Childhood is believed to be a susceptible window for long-term harmful effects of UV, as evidenced by clear differences in skin cancer risk between child and adult migrants from high to low latitudes. Effective UV radiation protection from childhood is necessary to control both immediate and long-term harmful effects on children’s skin.     

"Halo nevi" and UV radiation

Halo nevi, also termed Sutton nevi, are defined as benign melanocytic nevi that are surrounded by an area of depigmentation resembling a halo. Halo nevi are common in children and young adults, with a mean age at onset of 15 years. The incidence in the population is estimated to be approximately 1%. Affected individuals frequently have multiple lesions which are usually localized on the back. A familial tendency for halo nevi has been reported. The etiology of halo nevi is unknown. It is an autoimmune response and T lymphocytes are considered to play a key role in the progressive destruction of nevus cells. Halo nevi may be associated with autoimmune disorders such as vitiligo, Hashimoto thyroiditis, alopecia areata, celiac disease, atopic dermatitis and others. It has been proved that halo nevi are detected after an intense sun exposure especially after sunburns. The etiology of halo nevi, association with malignant melanoma and the role of sun exposure in the development of halo nevi are discussed.     

Paternal investment and status-related child outcomes: timing of father's death affects offspring success

Recent work in human behavioural ecology has suggested that analyses focusing on early childhood may underestimate the importance of paternal investment to child outcomes since such investment may not become crucial until adolescence or beyond. This may be especially important in societies with a heritable component to status, as later investment by fathers may be more strongly related to a child's adult status than early forms of parental investment that affect child survival and child health. In such circumstances, the death or absence of a father may have profoundly negative effects on the adult outcomes of his children that cannot be easily compensated for by the investment of mothers or other relatives. This proposition is tested using a multigenerational dataset from Bangalore, India, containing information on paternal mortality as well as several child outcomes dependent on parental investment during adolescence and young adulthood. The paper examines the effects of paternal death, and the timing of paternal death, on a child's education, adult income, age at marriage and the amount spent on his or her marriage, along with similar characteristics of spouses. Results indicate that a father's death has a negative impact on child outcomes, and that, in contrast to some findings in the literature on father absence, the effects of paternal death are strongest for children who lose their father in late childhood or adolescence.     

Consensus and Controversy Regarding Osteoporosis in the Pediatric Population

ObjectiveTo review current consensus and controversy surrounding the diagnosis and treatment of osteoporosis in childhood and adolescence.MethodsThe medical literature was reviewed with emphasis on the importance of early skeletal health, risk factors for bone fragility, and the diagnosis and management of children at risk for osteoporosis.ResultsChildhood and adolescence are critical periods for optimizing bone growth and mineral accrual. Bone strength is determined by bone size, geometry, quality, and mass—variables that are influenced by genetic factors, activity, nutrition, and hormones. For children with genetic skeletal disorders or chronic disease, bone growth and mineral accrual may be compromised, increasing the lifetime risk of osteoporosis. The goal for the clinician is to identify children at greatest risk for future fragility fracture. Bone densitometry and turnover markers are challenging to interpret in children. Prevention and treatment of bone fragility in children are less well established than in adults. Optimizing nutrition and activity may not restore bone health, but the drug armamentarium is limited. Sex steroid replacement has not proven effective in restoring bone mass in patients with anorexia nervosa or exercise-associated amenorrhea. Bisphosphonates can increase bone mass and may reduce bone pain and fractures, most convincingly in patients with osteogenesis imperfecta. Further studies are needed to establish the safety, efficacy, and optimal drug, duration, and dosage in pediatric patients.ConclusionBone health during the first 2 decades contributes to the lifetime risk of osteoporosis. Further research is needed to develop evidence-based recommendations for the diagnosis and treatment of osteoporosis in childhood. (Endocr Pract. 2007;13:513-520)     

Neonatal susceptibility to UV induced cutaneous malignant melanoma in a mouse model.

UV irradiation has multiple effects on skin including erythema, immunosuppression and the induction of keratinocyte-derived skin cancers and cutaneous malignant melanoma (CMM). CMM which arises from damage to the melanocyte, the pigment cell of the skin, is associated in epidemiologic studies with sun-exposure of susceptible populations, especially children. Our experimental studies have supported the concept that the epidemiologically observed susceptibility in children has a biologic basis. Hepatocyte growth factor/scatter factor (HGF/SF) transgenic mice neonatally irradiated with UV produce melanomas which recapitulate human disease in histopathology and molecular pathogenesis. In this model, neonatal UV is necessary and sufficient for melanoma induction although an additional adult dose of UV radiation significantly increased melanoma multiplicity. One hypothesis for the susceptibility of neonatal mice to induction of melanoma is that neonatal skin contains a large number of immature melanocytes which may result in the retention of the consequences of UV damage throughout the lifetime of the animal. An alternate hypothesis is that the immaturity of the neonatal immune system results in tolerance to melanocytic antigens produced by UV exposure, thus permitting the subsequent outgrowth of melanoma. Here, we discuss the current state of knowledge about the differences between adult and neonatal mice in melanocytes and immune maturation as possible factors playing a role in the susceptibility to melanoma in UV irradiated HGF/SF transgenic mice.     

Developmental changes of prefrontal activation in humans: a near-infrared spectroscopy study of preschool children and adults

Previous morphological studies indicated that development of the human prefrontal cortex (PFC) appears to continue into late adolescence. Although functional brain imaging studies have sought to determine the time course of functional development of the PFC, it is unclear whether the developmental change occurs after adolescence to adulthood and when it achieves a peak because of the narrow or discontinuous range in the participant's age. Moreover, previous functional studies have not focused on the anterior frontal region, that is, the frontopolar regions (BA9/10). Thus, the present study investigated the developmental change in frontopolar PFC activation associated with letter fluency task by using near-infrared spectroscopy (NIRS), in subjects from preschool children to adults. We analyzed the relative concentration of hemoglobin (ΔHb) in the prefrontal cortex measured during the activation task in 48 typically-developing children and adolescents and 22 healthy adults. Consistent with prior morphological studies, we found developmental change with age in the children/adolescents. Moreover, the average Δoxy-Hb in adult males was significantly larger than that in child/adolescent males, but was not true for females. These data suggested that functional development of the PFC continues into late adolescence. Although the developmental change of the frontopolar PFC was independent of gender from childhood to adolescence, in adulthood a gender difference was shown.     

Solar lentigines are strongly related to sun exposure in contrast to ephelides

Solar lentigines and ephelides are different types of pigmented skin lesions predominantly present on sun-exposed skin. Both lesions are risk indicators for melanoma and non-melanoma skin cancer. Solar lentigines are considered as a sign of photodamage although well-conducted epidemiological studies are lacking on this subject. Ephelides are associated with fair skin type and red hair. The aim of the present study was to investigate the relation of sun-exposure estimates with solar lentigines and ephelides. In the Leiden Skin cancer Study 577 patients with malignant melanoma and/or non-melanoma skin cancer and 385 individuals without a history of skin cancer were studied. The presence of solar lentigines and ephelides in the face and on the back was assessed. Data on skin type, hair color, sun-exposure variables and cutaneous signs of photodamage were collected, by questionnaire and physical examination. Data were analyzed by chi-square or Student t-tests and with multivariable regression. Exposure odds ratios with 95% confidence intervals (95% CI) were calculated to estimate the relative risk for the presence of solar lentigines and ephelides dependent on signs of photodamage. The association with age was strongly positive for solar lentigines whereas it was strongly negative for ephelides (P-values for trend <0.0001). After adjustment for age, sex and skin type, solar lentigines on the back were positively associated with cumulative (P = 0.01) and intermittent (P = 0.0002) sun exposure. After adjustment, solar lentigines on the back were also associated with a history of sunburns before the age of 20 yr (P = 0.0003) and the number of sunburns in childhood (P = 0.002). Solar lentigines in the face were significantly associated with cutaneous signs of photodamage, i.e. elastosis (odds ratio 2.4, 95% CI 1.7-3.3) and actinic keratosis (odds ratio 1.8, 95% CI 1.3-2.4) whereas ephelides were not. Ephelides in the face and on the back showed an inverse association with chronic sun exposure but after adjustment theses associations disappeared. Sunburns before the age of 20 appeared to be positively associated with ephelides on the back (P = 0.04). In contrast to lentigines, ephelides were much more associated with constitutional host factors such as fair skin and/or red hair (both P < 0.0001). This study indicates that both chronic and acute sun exposure are important in the pathogenesis of solar lentigines.     

UV and children's skin

There is indicative epidemiological evidence that exposures of children younger than about 10 years are linked with an increased risk of the development of malignant melanoma as well as non-melanocytic skin cancers later in life. However, an important area of uncertainty relates to lack of knowledge of the sun-sensitivity of children's skin both absolutely and relative to that of adult's skin. For example the thickness of children's skin is very similar to that of adults but due to the nature of the anatomical structure of children's skin, there are indications of children's skin being adversely exposed on the top of the papilla before a significant exposure manifests itself as visible damage to the skin (for example erythema). This might also affect the induction of heavily UV-damaged cells persisting in the basal layer of the epidermis after UV-exposure which are supposed to be keratinocytic epidermal stem cells and may characterize an initiation step of non-melanoncytic skin cancer. For malignant melanoma the number of nevi received in dependence of UV-exposure in childhood is a clear risk factor. Recent data show that the bulge region of hair follicles hosting melanocytic stem cells are located deeper (more protected) in the skin in adults (terminal hair) as compared to pre-pubertal children (vellus hair). This may be an explanation for enhanced risk of malignant melanoma due to UV-exposure in pre-pubertal childhood.     

Serum antibodies to Giardia lamblia by age in populations in Colorado and Thailand.

We measured levels of antibodies to Giardia lamblia by age in serum specimens from persons in Denver, Colorado, and Soongnern, Thailand. Serum levels of immunoglobulin (Ig) G, IgM, and IgA G lamblia-specific antibodies measured by enzyme-linked immunosorbent assay increased substantially during childhood in both geographic areas, although children in Soongnern showed significantly higher mean levels of each antibody class (P less than .05). After adolescence, levels of G lamblia-specific IgM fell steadily with age in both populations. In contrast, specific IgA levels remained elevated throughout life among the Thai but decreased to low levels among adults in Denver. Similarly, rates of carriage of G lamblia were high among children aged 1 to 4 years in Denver and Soongnern (14.3% versus 26.5%, respectively) but were much lower among adults in Denver (0% versus 14%; P less than .01). These data suggest that levels of G lamblia-specific IgM may reflect exposure to the parasite early in life in both areas. Levels of parasite-specific IgA may reflect recurrent exposure to G lamblia in Soongnern, where G lamblia is endemic, but less frequent exposure to the parasite in Denver, where exposure is often episodic.     

Ultraviolet exposure and vitamin D synthesis in a sun-dwelling and a shade-dwelling species of Anolis: are there adaptations for lower ultraviolet B and dietary vitamin D3 availability in the shade?

We compared the natural ultraviolet B (UV-B) exposure, dietary vitamin D, and skin-generated vitamin D synthesis for adult males of two species of Jamaican anoles. The more shade-tolerant and thermal-conforming Anolis lineotopus merope, rarely exposed to full sun, experienced less UV-B irradiation in its shady environment than the more heliophilic and thermophilic Anolis sagrei, which frequently basked in full sun during the morning hours (0800-1100 hours). Both species obtained detectable levels of vitamin D(3) in their diet, but the heliophilic A. sagrei obtained more. To compensate for less availability of UV-B and dietary vitamin D, the skin of A. lineotopus merope seems to have acquired a greater sensitivity than that of A. sagrei regarding UV-B-induced vitamin D(3) photobiosynthesis. We assessed this by observing a greater conversion of provitamin D to photoproducts in skin exposed to UV-B from a sunlamp. The reduced skin sensitivity of A. sagrei regarding vitamin D photobiosynthesis may reflect a correlated response associated with less need for vitamin D photobiosynthesis and greater need for UV-B screening capacity as an adaptation to a more damaging UV-B environment. However, the possibility that adaptations for photobiosynthesis of vitamin D and for protection from skin damage could involve independent mechanisms needs investigation. Also, the ability to behaviorally regulate UV-B exposure, as shown for the panther chameleon, would benefit both species of Anolis and should be investigated.     

Longitudinal associations of adiposity with adult lung function in the Childhood Determinants of Adult Health (CDAH) study

Childhood BMI has been reported to be positively associated with adult lung function. The aim of this study was to investigate the effect of childhood BMI on young adult lung function independently of the effects of lean body mass (LBM). Clinical and questionnaire data were collected from 654 young Australian adults (aged 27-36 years), first studied when age 9, 12, or 15 years. Adult lung function was measured by forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC ratio, and the forced expiratory flow in the middle 50% of FVC (FEF(25-75)). BMI and LBM were derived from anthropometric measures at baseline (1985) and at follow-up (2004-2006). Multivariable models were used to investigate the effect of age and sex standardized BMI in childhood on adult lung function, before and after adjustment for LBM. Adult adiposity had a strong deleterious effect on lung function, irrespective of childhood BMI, and adjustment for childhood LBM eliminated any apparent beneficial effect of childhood BMI on adult FEV(1) or FVC. This suggests that the beneficial effect of increased BMI in childhood on adult FEV(1) and FVC observed in previous longitudinal studies is likely to be attributable to greater childhood LBM not adiposity. Obese children who become obese adults can expect to have poorer lung function than those who maintain healthy weight but large deficits in lung function are also likely for healthy weight children who become obese adults. This highlights the importance of lifetime healthy weight maintenance.     

Developmental and transplacental genotoxicology: fluconazole

Over the last 40 years mankind has been facing new types of radiochemical environmental settings with every decade. During the last decade, biomonitoring was additionally focused on assessing associations between environmental exposure(s) and both early and late biological effects in children. Despite efforts to control and avoid child exposure to genotoxic agents the incidence of childhood cancers is increasing. Some cancers in adulthood may be the consequence of a multi-step process which starts with intrauterine and childhood exposure. This highlights the importance of a comprehensive interpretation of multiple health effects, especially considering recent studies suggesting that most health disorders are related to DNA changes. When exposed to genotoxic agents, a developing organism (fetus or child) is constantly being forced to reorganize into new equilibriums in order to adjust to a xenobiotic environment. In addition, the influence of sex hormones on radiochemical sensitivity is still unknown. For this reason special attention should be paid to puberty. The results of recent studies on animal models and follow up studies on children after nuclear accidents show long-lasting cytogenetic damage even after low dose exposures and their transgenerational persistance. To evaluate age-related difference and transplacental genotoxic potency fluconazole (FC) was investigated by in vivo micronucleus (MN) assay in adult mice, young mice and in transplacentally exposed newborn pups. Compared to the baseline values, FC caused no detectable genome damage in adult animals, but there was a significant increase in MN frequency in young animals and in newborn pups. Our study thus exemplifies an age-related chemosensitivity, and argues that cancer-promoting disturbances of complex prenatal developmental mechanisms and maturation during childhood require a new approach using systems biology.