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Skin and skin types
When sunlight hurts
Sunshine puts us in a good mood. This is true for most people. But some people suffer under the sun and its rays. Unfortunately, simply applying sunscreen is not enough for these people.
In our series on the interplay between people and the sun, we examine the reactions that light, especially UV light, triggers in the human body. We began by looking at IR radiation. In contrast to UV rays, which are not visible or directly perceptible, IR radiation is clearly noticeable. Our body absorbs its energy and the molecules start to dance around. The result of this is heat. Click here for the article on IR radiation.
When it comes to the reactions caused by UV radiation, photodermatoses, of which there are multiple variants, play a major role. Colloquially, these conditions are often grouped together and described as sun allergies. Strictly speaking, however, they are not allergies. Although, almost all of the disorders result from the direct influence of light and UV radiation on the body. If light and radiation are responsible for the health problems, they are also referred to as primary photodermatoses. In these cases, skin changes occur in the areas of the body exposed to the sun.
Then there are secondary photodermatoses. Although light also plays a major role in these conditions, it is other internal causes that lead to the problems. Light and radiation act as a sort of trigger in these cases and affect the disorder. Genetic defects, metabolic disorders or autoimmune reactions are among the causes of secondary photodermatosis. A painful and dangerous interplay of factors.
When the sun becomes your enemy
Have you ever heard or read about xeroderma pigmentosum (XP) or erythropoietic protoporphyria (EPP)? Both are genetic and very rare disorders. In German, XP is often colloquially referred to as “moonlight disease”, and EPP is known colloquially as “shadow jumper disease”. Both disorders have one striking similarity, which is tragic for sufferers: they bring darkness into life.
February 29 is a rare date
That is probably why the last day of February is always “Rare Disease Day”. Around this date, you usually learn something about both of the conditions mentioned above. Sufferers need this attention. Not only so that research can continue, but also so that other people can understand them better.
More information in german : Allianz Chronischer Seltener Erkrankungen (ACHSE) e.V.
It may seem a bit strange when you meet someone in the middle of summer, with the sun shining down from a bright blue sky, who is bundled up from top to bottom as if the temperature was below freezing. From their beanie to their face covering and their gloves to their long pants; only their sunglasses seem “normal”. Many people may think this person is eccentric and may even wrinkle up their nose at them. However, people who dress like this in summer, or in fact have to dress like this, do not do it voluntarily. Their medical condition forces them to do it. They have to wear special suits to go for walks. And even indoors, windows must be covered with UV protective film.
A life in the dark
Xeroderma pigmentosum (XP) becomes noticeable at a very young age. Photophobia can develop from around two years of age. Children instinctively try to protect their eyes from the sun. This strong photosensitivity may be an early indication of XP. It is followed by pathological skin changes. Brown spots can be seen on the face and the skin appears generally dry. Depending on the genetic variant, skin cancer often develops even before 20 years of age. Premature skin aging also increases.
The cause of this disorder is a defective DNA repair system. Especially the areas of the body exposed to the sun are at risk of cancer. UV-B radiation in particular damages the skin.
XP is not only rare, but also far from being fully researched. Despite being identified by Viennese dermatologist Moriz K. Kaposi in 1870, there is still no cure in sight. Sufferers must avoid UV light. Their light-sensitive skin must not get any radiation. Moonlight does not harm them, which is why they are commonly referred to in Germany as “moonshine children”.
Erythropoietic protoporphyria (EPP) is also a genetic disorder. In contrast to XP, the health problems are not visible, but patients feel them all the more strongly. EPP causes intolerable pain after just a few minutes of sun exposure. In addition to natural sun rays, artificial light sources can also cause the symptoms. The amount of blue light also shares some of the responsibility.
Looking at the progress reports of EPP patients, you can only begin to imagine what they have to go through. Internal burn pain makes them avoid light. The term “shadow jumper disease” describes the problem very well. Touch becomes intolerable. Neither cooling nor painkillers help. It even pushes morphines to the limits of their efficacy. People often find it hard to believe patients because of the invisibility of the disorder, and its severity is often trivialized.
A tanning hormone brings back some life
Unlike with XP, however, medicine has taken a step forward with EPP. Even though the step is not a permanent solution to the problem, it makes life a little more tolerable and allows sufferers to participate in life outdoors at least temporarily. In 2014, a drug was launched and approved, which allows patients to be outdoors for significantly longer without experiencing any symptoms. This is made possible by the active ingredient afamelanotide, which acts as an artificial tanning hormone, ensuring the skin is protected for a certain period of time. The drug allows people to live an almost normal life for some time.
Skin, our body’s largest organ
It has many functions. It not only forms a protective layer against environmental influences, it’s also visible to all of us - this is why its appearance and health are so important. It is composed of several layers, which in turn are subdivided into strata.
More informationHowever, it is important to note that tanning with afamelanotide is not to be confused with the use of self-tanners. These only color the skin and do not protect against UV radiation. Afamelanotide, however, is a synthetic form of a hormone that prompts skin cells in the body to make eumelanin. This increases tolerance to sunlight.
Fortunately, for most people, sun protection is not as difficult as for patients with XP and EPP. A life filled with light is not only easier, but also much more pleasant. But it is still important to take sunscreen seriously and think about your health.