Hier ein Nachtrag zu der Diskussion von letzter Woche bezüglich Sonnencreme und Melanomrisiko.
Der Dermatologen, mit dem ich mich darüber unterhalten habe, hat mir zwei Literaturstellen zum Thema geschickt.
Das Melanomrisiko bleibt trotz Sonnencreme bestehen(!) - bedingt durch die "Technik" beim Eincremen und der Auswahl der Sonnencreme (näheres im den abtracts).
Weiterhin existiert ein direkter Zusammenhang zwischen wiederholten Sonnenbränden und der Entstehung von Melanomen. Bei der Entstehung der Sonnenbrände spielt wieder der Umgang mit der Sonnencreme eine Rolle. Sonnencremes als Risikofaktor und Melanome stehen somit indirekt in Zusammenhang. Das hatte ich letzte Woche etwas falsch dargestellt.
Viele Grüße, Jörg
1: Acta Dermatovenerol Croat. 2003;11(3):158-62. Related Articles, Books
Sunscreens - the ultimate cosmetic.
Wolf R, Matz H, Orion E, Lipozencic J.
Head of Dermatology Unit Kaplan Medical Center Rechovot, Israel;wolf_r@netvision.net.il
One decade ago, a sun protection factor (SPF) of 15 was considered a complete blocker of ultraviolet radiation (UV). The logic behind that cutoff point was that sunscreens with this SPF number would always prevent erythema and that preventing erythema would prevent all the ill effects of UV exposure. Today, we know that both of these assumptions were wrong and we tend to recommend higher SPF. Consumers apply only about one-quarter to one-half thickness of the layer of sunscreen material used to measure the SPF in the laboratory. That means that less than 50% of the SPF number claimed on the label is spread on the consumer's skin, meaning that a sunscreen with an SPF 30 will give the real protection of an SPF of 15. Therefore, recommend 60 when you want a real protection of 30! Significant injury, DNA damage, mutations, and carcinogenesis can and do occur also with cumulative suberythemal UV exposure. Thus, erythema induction, a criterion that defines SPF, is not a good indicator of UV damage. We also need higher SPF values to prevent the damage caused by suberythemal doses of UV. The value of the SPF claimed on the label is diminished by environmental factors that are not taken into account during SPF measurements in the laboratory, such as sweating, water immersion, rubbing off, and photodegradation. There are some misunderstandings and confusion about the mode of action of physical sunscreens. It was originally considered that, in contrast to organic sunscreens, the inorganic metal oxides (zinc oxide and titanium dioxide) acted as scatterers or reflectors of UV light, as a mirror. This is not the case with modern micronized forms of metal oxides. It has been shown that both zinc oxide and titanium dioxide mobilize electrons within their atomic structure while absorbing UV radiation. Thus, although metallic oxides are not inert per se, in their coated form they are stable, non-toxic, and safe and they act as highly efficient UV attenuators. Therefore, we recommend our patients to use this type of sunscreens. We should exert all our influence upon our patients not to expose themselves to excessive sunlight, to routinely use generous layers of sunscreen agents, and to wear protective clothing. To wait for the dust to settle around the issue of the effectiveness of sunscreens in preventing melanoma, while the ideal sunscreens - topical, systemic, whatever - are at our disposal, is a luxury we cannot afford
Publication Types:
News
PMID: 12967508 [PubMed - in process]
2: J Photochem Photobiol B. 2001 Nov 15;64(2-3):105-8. Related Articles, Books, LinkOut
Sunscreen isn't enough.
Diffey B.
Regional Medical Physics Department, Newcastle General Hospital, Newcastle upon Tyne NE4 6BE, UK. b.l.diffey@ncl.ac.uk
Topical sunscreens act by absorbing or scattering UV radiation and are widely available for general public use as a consumer product. Surveys carried out in the UK find that sunscreen use is regarded as the most important, and by implication the most effective, sun protection measure. But is perception borne out by reality? Sunscreens applied at the thickness tested by manufacturers need only possess an SPF of 15 to prevent sunburn even for all day exposure in tropical sunshine. Yet behavioural studies show that high SPF (>15) sunscreens do not always prevent sunburn. That the protection achieved is often less than that expected depends upon a number of factors: application thickness and technique; type of sunscreen applied; resistance to water immersion and sand abrasion; and when, where and how often sunscreen is re-applied. These factors provide ample evidence that the numerical measure of protection indicated on the product pack is generally higher than achieved in practice. This mismatch between expectation and realisation may be one contributing factor why sunscreens have been reported to be a risk factor in melanoma.
Publication Types:
Review
Review, Tutorial
PMID: 11744396 [PubMed - indexed for MEDLINE]
Der Dermatologen, mit dem ich mich darüber unterhalten habe, hat mir zwei Literaturstellen zum Thema geschickt.
Das Melanomrisiko bleibt trotz Sonnencreme bestehen(!) - bedingt durch die "Technik" beim Eincremen und der Auswahl der Sonnencreme (näheres im den abtracts).
Weiterhin existiert ein direkter Zusammenhang zwischen wiederholten Sonnenbränden und der Entstehung von Melanomen. Bei der Entstehung der Sonnenbrände spielt wieder der Umgang mit der Sonnencreme eine Rolle. Sonnencremes als Risikofaktor und Melanome stehen somit indirekt in Zusammenhang. Das hatte ich letzte Woche etwas falsch dargestellt.
Viele Grüße, Jörg
1: Acta Dermatovenerol Croat. 2003;11(3):158-62. Related Articles, Books
Sunscreens - the ultimate cosmetic.
Wolf R, Matz H, Orion E, Lipozencic J.
Head of Dermatology Unit Kaplan Medical Center Rechovot, Israel;wolf_r@netvision.net.il
One decade ago, a sun protection factor (SPF) of 15 was considered a complete blocker of ultraviolet radiation (UV). The logic behind that cutoff point was that sunscreens with this SPF number would always prevent erythema and that preventing erythema would prevent all the ill effects of UV exposure. Today, we know that both of these assumptions were wrong and we tend to recommend higher SPF. Consumers apply only about one-quarter to one-half thickness of the layer of sunscreen material used to measure the SPF in the laboratory. That means that less than 50% of the SPF number claimed on the label is spread on the consumer's skin, meaning that a sunscreen with an SPF 30 will give the real protection of an SPF of 15. Therefore, recommend 60 when you want a real protection of 30! Significant injury, DNA damage, mutations, and carcinogenesis can and do occur also with cumulative suberythemal UV exposure. Thus, erythema induction, a criterion that defines SPF, is not a good indicator of UV damage. We also need higher SPF values to prevent the damage caused by suberythemal doses of UV. The value of the SPF claimed on the label is diminished by environmental factors that are not taken into account during SPF measurements in the laboratory, such as sweating, water immersion, rubbing off, and photodegradation. There are some misunderstandings and confusion about the mode of action of physical sunscreens. It was originally considered that, in contrast to organic sunscreens, the inorganic metal oxides (zinc oxide and titanium dioxide) acted as scatterers or reflectors of UV light, as a mirror. This is not the case with modern micronized forms of metal oxides. It has been shown that both zinc oxide and titanium dioxide mobilize electrons within their atomic structure while absorbing UV radiation. Thus, although metallic oxides are not inert per se, in their coated form they are stable, non-toxic, and safe and they act as highly efficient UV attenuators. Therefore, we recommend our patients to use this type of sunscreens. We should exert all our influence upon our patients not to expose themselves to excessive sunlight, to routinely use generous layers of sunscreen agents, and to wear protective clothing. To wait for the dust to settle around the issue of the effectiveness of sunscreens in preventing melanoma, while the ideal sunscreens - topical, systemic, whatever - are at our disposal, is a luxury we cannot afford
Publication Types:
News
PMID: 12967508 [PubMed - in process]
2: J Photochem Photobiol B. 2001 Nov 15;64(2-3):105-8. Related Articles, Books, LinkOut
Sunscreen isn't enough.
Diffey B.
Regional Medical Physics Department, Newcastle General Hospital, Newcastle upon Tyne NE4 6BE, UK. b.l.diffey@ncl.ac.uk
Topical sunscreens act by absorbing or scattering UV radiation and are widely available for general public use as a consumer product. Surveys carried out in the UK find that sunscreen use is regarded as the most important, and by implication the most effective, sun protection measure. But is perception borne out by reality? Sunscreens applied at the thickness tested by manufacturers need only possess an SPF of 15 to prevent sunburn even for all day exposure in tropical sunshine. Yet behavioural studies show that high SPF (>15) sunscreens do not always prevent sunburn. That the protection achieved is often less than that expected depends upon a number of factors: application thickness and technique; type of sunscreen applied; resistance to water immersion and sand abrasion; and when, where and how often sunscreen is re-applied. These factors provide ample evidence that the numerical measure of protection indicated on the product pack is generally higher than achieved in practice. This mismatch between expectation and realisation may be one contributing factor why sunscreens have been reported to be a risk factor in melanoma.
Publication Types:
Review
Review, Tutorial
PMID: 11744396 [PubMed - indexed for MEDLINE]
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