Guidelines on sunscreen product labeling need to be improved according to the European Commision, which plans to issue a recommendation in 2007 ensuring a clear, standardized procedure in the future.
One of the most important factors relates to confusion over the two types of hazardous UV radiation; UVA and UVB. The sun protection factor only relates to UVB exposure, which causes sunburn. UVA is mentioned less frequently in the product information, yet it is the main cause of premature skin-aging, interferes with the immune system and contributes to the risk of skin cancer.
Markos Kyprianou, the commissioner responsible for consumer health and protection, stated that it is important to make consumers aware that no sunscreen provides 100% protection against UV radiation and that insufficient protection from the sun is linked to skin cancer. They must therefore be fully informed about the actions of particular sunscreens.
The European commission aims to improve labeling by enforcing standardized procedures, such as banning the use of misleading words (e.g., sunblock) and ensuring that warnings about usage instructions are understandable. If a product is applied in the incorrect quantity and not re-applied frequently enough, it might be rendered useless. They also propose an indication of UVA protection based on uniform testing methods. This will eradicate the inconsistency between the ways different companies currently measure UVA protection, which may be misleading.
Until the new legislation is in place, consumers are advised to choose sunscreen products that protect against both UVA and UVB radiation. In addition, it is recommended that sun exposure is avoided during peak hours, protective clothing, such as hats and sunglasses, is worn, and babies and young children should not be exposed to direct sunlight at all.
Dermoscopy improves the detection of malignant skin lesions
Using dermoscopy, malignant lesion detection by primary care physicians could be more sensitive in 25% of cases.
Primary care physicians deal with basic health problems and then refer patients to specialists based on their own pathological diagnosis. The efficiency of this process is clearly very important, as correct diagnoses at the primary level would help in the fight against skin cancer and reduce the number of patients visiting specialized dermatology clinics unnecessarily. Patients are also more likely to be reassured if their physicians are confident in their own diagnosis.
A study by researchers of the Institut d'Investigacions Biomèdiques August Pi I Sunver, and published in the Journal of Clinical Oncology, investigated the ability of 73 physicians to identify malignant tumors. All participants underwent a 4-h course in dermoscopy techniques. They were then separated into two study groups; a group with a dermoscope and a control group without. During a 6-month trial, 3271 patients with skin complaints were visited by these primary care physicians. Those who were not using dermoscopy referred a greater number of patients to a specialist and diagnosed fewer cases of malignancy, thereby overlooking patients potentially at risk from skin cancer. When physicians used dermoscopy, specificity was maintained and the sensitivity of detection increased from 54.1 to 79.2%. The number of false negative diagnoses was also significantly decreased.
Dermoscopes contain an illuminated magnifier, which allows the visualization of the morphological characteristics of skin melanomas. Using criteria including the asymmetry of color or structure, the presence of a net of irregularly distributed black lines and the identification of white or blue structures, it is possible to identify a potentially malignant tumor with reasonalble confidence. If this is the case, the patient should be refered to a specialist immediately.
This study clearly demonstrates the usefulness of dermoscopy as a technique for accurately identifying malignant skin lesions at an early stage and avoiding unnecessary biopsies.
Novel therapeutic approach to treat skin disorders based on genetic research
Genetic research has shown that the protective properties of the skin are disrupted by excessive production of a protein, following expression of the connexion 26 gene. Treatments that target this protein might be effective in skin disorders, asthma and hay fever.
When the skin barrier is compromized, allergens can access the immune system more easily. This stimulates rapid skin-cell growth, which further diminishes the protective properties of the skin and leads to a cycle of inflammation and damage, eventually causing conditions such as eczema and psoriasis. Current therapies focus on immunosuppression and can have undesired adverse effects.
Research from the National Institutes of Health, published in the Journal of Clinical Investigation, suggests that a lotion could be developed that blocks allergens from penetrating damaged skin and, therefore, breaks the cycle and allows the skin to regenerate normally. The target is a protein produced from the expression of connexin 26 that forms intercellular connections and this gene is switched off during normal skin regeneration when enough protein has been produced. Connexin 26 was also previously demonstrated to be expressed in the sore skin of psoriasis patients so, in order to determine its role in the disorder, transgenic mice were created that overexpressed the gene. These mice developed psoriatic-like skin sores.JA Segre, an investigator at NHGRI, said that while previous studies have focused on genes that regulate the immune response, current research is examining genes that regulate skin-cell growth and signal to immune cells.Researchers must now focus both on turning down the immune response and restoring a normal skin barrier. Understanding the genetics of skin disorders will also have implications in the treatment of more serious, related illnesses, such as asthma.
Interleukin-31 expression linked to atopic dermatitis
The newly discovered T-cell cytokine, interleukin (IL)-31 has been shown to cause skin dermatitis and pruritus that resembles human atopic dermatitis when overexpressed in mice.
J Bilsborough and coworkers at ZymoGenetics Inc. (Seattle, USA) studied peripheral blood cells and skin biopsy specimens from atopic dermatitis patients and controls. They measured IL-31 and IL-31 receptor A (IL-31RA) expression using immunohistochemistry and the reverse transcriptase polymerase chain reaction.
Results published in the Journal of Allergy and Clinical Immunology showed that keratinocytes expressed IL-31RA protein at higher levels in biopsies from atopic dermatitis patients than controls.
Infiltrating macrophages were also more numerous in the skin of atopic dermatitis patients and expressed IL-31 mRNA. The majority of these cells were lymphocytic and stained positive for cutaneous lymphocyte antigen (CLA) and CD3.
Circulating CLA+ T cells from patients with atopic dermatitis are capable of producing higher levels of IL-31 than CLA+ T cells from healthy individuals. However, the average production is not significantly different and the same trend is not the case for psoriasis.
These results demonstrate that IL-31 expression is linked to CLA+ T cells and might be a factor in the development of atopic dermatitis-induced skin disease.
Babies exposed to cats may be more likely to develop eczema
Exposure of new born babies to cats might increase the risk of these children developing eczema. A study presented at the American Thoracic Society International Conference on May 21st followed 486 children from birth and found that 27.6% of the children with cats in their houses developed eczema by 1 year of age compared with just 17.8% of those without. In addition, this effect was more pronounced in children who’s mothers did not suffer from asthma.
Being exposed to at least two dogs had a slightly protective effect but this was not statistically significant. Although previous research has shown that people with eczema are more likely to also develop allergic conditions, such as asthma and hay fever, studies have also shown that pets can help protect against allergic diseases because they are a source of endotoxin. If a child is exposed to this early in life, their immune system is better able to cope with allergens.
Dr Esmeralda Morales, a Pediatric Pulmonary Fellow at the University of Arizona (AZ, USA) suggested that the children from this study who developed eczema might have a reduced risk of asthma and other allergic diseases later in life. She also stressed that more research is required on the topic as there are a lot of contradictory results.
Gene linked to skin cancer
A gene first associated with a rare disease that causes patients to develop multiple benign skin tumors has now been linked to cancers located throughout the body. A study published in Cell reported that deletion of the CYLD gene leads to a disease called familial cylindromatosis, in which tumors develop in hair-follicle cells.
Reinhard Fässler and coworkers of the Max Planck Institute of Biochemistry in Germany identified a second role for the CYLD enzyme. It has been shown to modify the cancer-promoting protein Bcl-3 by binding to it and blocking its entry into the cell nucleus and, therefore, preventing the proliferation of cancerous cells.
Knockout mice lacking CYLD were twice as likely to develop skin tumors when exposed to carcinogenic chemicals than wild-type mice. In addition, the mutant mice developed significantly larger and approximately seven-times the number of tumors than controls. The difference was found to be in the proliferation of cells rather than cell survival. When treated with tumor-inducing chemicals, cells deficient in CYLD accumulated Bcl-3 and cancerous cells were therefore able to proliferate.
These results might also help to elucidate the processes underlying skin cancer development. It was discovered that most of the tumors developed from cells in the epidermis rather than hair-follicle cells. This finding led the researchers to investigate CYLD expression in the two most common forms of skin cancer; basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Many samples of BCC and SCC showed reduced or absent CYLD expression, which strongly suggests that the gene has a role in tumor suppression and its absence is a factor in skin cancers. Research is now underway to investigate if CYLD expression is also altered in other forms of cancer.