On 31 January 2012 Swiss TV channel Telezueri aired a report on erythropoietic protoporphyria (EPP), a rare genetic disorder which causes absolute intolerance of skin to sunlight, and Clinuvel’s novel drug SCENESSE® (afamelanotide), which has been trialled as a photoprotective in EPP. Clinuvel has subtitled the 'Check up' program and re-released for the broader EPP community.
Following Clinuvel's landmark filing of a marketing authorisation application for the drug SCENESSE® (afamelanotide) with the European Medicines Agency, CEO Dr Philippe Wolgen discusses the challenges to date and what may lie ahead for Clinuvel.
Have you ever wondered why you have been sunburnt on a cloudy day? Harmful ultraviolet (UV) rays can still penetrate the earth's atmosphere. To help understand why you can still get burnt in these (and other) situations, we've produced a short video on why UV levels vary. Produced by Clinuvel clinuvel.com
The total dose of UV radiation reaching the earth's surface, and hence the potential damage to human skin and tissues, varies, depending on many factors.
The sun's elevation in the sky depends on the time of the day and year. The shorter the distance that photons of UV radiation need to travel though the earth's atmosphere, the greater the intensity of UV on earth. The altitude of a location also effects UV radiation levels, as the higher a location is above sea level, the shorter the distance UV radiation needs to travel to reach the land.
The thinning of the ozone layer located above Antarctica has had a considerable impact on the ability of the atmosphere to absorb UVB: a significant contributor to the increased incidence of skin cancer and other damage to human tissues which has been observed in populations bordering the ozone hole.
Clouds act on UV, primarily, by scattering radiation. This effect can either reduce or enhance UV radiation levels, depending on the type of cloud cover. Some clouds absorb infrared radiation and as a result of the diminished heat sensation, people are given a false sense of security. They often change their behaviour on cloudy days, unaware that they are exposing themselves to this potential danger.
UV radiation is also reflected from surfaces such as sand, snow and water. These surfaces can increase the UV radiation at ground level and increase the amount of skin damage incurred from UV radiation exposure.
When all these factors are considered, it is important to recognise that the net potential UV risk is a result of these associated variables and will depend on an individual's circumstances. The only sure way to significantly reduce the risk of skin damage is with vigilant protection from UV radiation and light, known as photoprotection.
Image and video credits:
ESA/Hubble (M. Kornmesser & L. L. Christensen)
Ozone layer video courtesy of NASA
NASA Goddard Space Flight Center
Skin cancer and ultraviolet-B radiation under the Antarctic ozone hole: southern Chile, 1987--2000, Jaime F. Abarca, Casiccia - 2002
Global solar UV index: A practical guide, World Health Organization - 2002
Sources and measurement of ultraviolet radiation, Diffey - 2002
Mikey describes the intense pain of EPP as "feeling like your skin is burning off".
EPP is a genetic disease that causes severe phototoxicity (toxic reactions to light). When skin is exposed to light, especially blue light, it results in excruciating pain, swelling and blistering that may lead to scarring. The condition is referred to as "absolute intolerance to light", a fitting name as patients are forced to seek shadows and avoid light.
Mikey's determination to enjoy a camping trip with school friends when he was 11 years old resulted in an agonising reaction that left him with a vivid memory of the experience. Despite being fully covered by protective clothing and wide brimmed hat, the reflected light from the ground and vegetation was relentless and burnt his face resulting in intense pain and swelling.
Most people cannot understand how sensitive EPP patients are to sunlight and the intensity of pain they experience when exposed. Mikey's quality of life, like all patients with Erythropoietic Protoporphyria (EPP), is severely affected. Severe pain forces him into living a nocturnal life or enduring outdoor activities in great discomfort and pain. Throughout his life Mikey has been unable to experience the outdoor activities that many take for granted without the protection of clothing that completely blocks the sun such as a boiler suit, balaclava and gloves. Socialising with friends is difficult and "the pain just isn't worth it" so he avoids social situations where he will be outside.
Isolation and unrelenting pain from sun exposure greatly impacts the quality of life of EPP patients. With no effective treatment currently available to them, sun avoidance is their only option. Forced to remain indoors, EPP patients eventually succumb to a nocturnal existence, the only way of life for many porphyria patients.