Sunburn

The sunburn ( med: UV erythema, erythema solar, dermatitis solaris ) is a burning of the skin first to second degree, caused by the UV - B fraction of the light. It comes within 1-6 hours after tanning to sharply defined erythema, flushing, itching, pain, sometimes blistering and edema of the irradiated skin. The symptoms will peak after 12-24 hours and resolve within three to seven days with desquamation back. In the face, it can also cause binding and inflammation of the cornea of the eye come (conjunctivitis and keratitis solaris ). If wide sunburn fever, weakness, and headache may occur. Through history and clinical findings is sunburn from other photodermatoses as Phytophotodermatitis, phototoxic dermatitis, urticaria and the like. well distinguishable.

Usually cure the symptoms without scar, with a reversible hyperpigmentation ( darkening ) of the skin. More severe burns can leave pale scars. Although the disease is harmless at first, but the child's sunburn is considered to be the most important risk factor for skin cancer ( malignant melanoma).

Frequency

Sunburn is an everyday experience. One in six U.S. adults get at least one sunburn, one in ten two, one in eleven three or more per year. From three children had two in the last year at least one sunburn; used among all age groups, only a minority sun protection measures. Non-white Americans get only slightly less frequently sunburn. In Switzerland and in Germany conscious sun protection measures in the population is similarly low spreads, with the exception of parents of young children.

Causes

Biologically effective in the skin are mainly UVB radiation ( 280-320 nm), as they are short-wave and thus energy. They result in excessive dosage strand breakage of DNA. You may also damage the microRNA are significant. UVA penetrates deeper into the skin and damages there the collagen of the dermis, resulting in the loss of skin elasticity. In very high doses, but also causes UVA both sunburn and DNA damage (mutations ) and thus skin cancer.

Pathomechanism of the sunburn is a radiation-induced damage to the epidermal cells, which caused by release of mediators inflammation of the dermis ( subcutaneous ). There is an enlargement of the tubes, and subsequently to the red color of the skin, to increased blood flow ( heating ), and leakage of fluid into the tissue ( bubble formation). Earliest histological characters are vacuolated keratocytes, so-called sunburn cells.

Risks

Sunburn occurs when any excessive sun exposure, but mainly in fair-skinned people of skin types I and II These individuals have a shorter self-protection time. or minimal erythema dose MED. The MED is the winter pale skin type I in Central Europe, summer, noon, at 10-45 min ( Worret / Gehring 2004), according to another source ( Altmeyer / Hoffmann 2006) at 20 min. Frequently recurring charges just below the MED can cause chronic skin damage ( wrinkles, spots ) and promote skin cancer.

You can prevent the sunburn of sunlight exposure, opaque clothing, and applying sunscreen. It should be noted that window glass and ordinary textiles passing a portion of the UV-B radiation, for example Polyethylene 42%, cotton 11% dry. Water absorbs UV -B only slightly (50 % at 1 m depth), so snorkellers are particularly vulnerable. Snow reflects the radiation to almost 100 %, thus increasing the risk of sunburn significantly (see Worret / Gehring 2004).

A suddenly increased UV index, eg by winter vacation in the tropics, or the exposure of otherwise covered skin ( in the spring, the swimming pool ) is also risky even for adults. Then should be used definitely sunscreen, even if cool air on the effect of solar radiation is deceptive. After a few weeks, the skin protects by pigmentation with melanin and a thickened horny layer ( light calluses ).

The eye lens, however, accumulated damage by UVB and is aged cloudy (cataract ). An acute danger for the eyes is the so-called snow blindness, a kind of sunburn of the cornea of the eye. Depending on the duration of stay in the sun special glacier or snow goggles should be used. Also, water and light sand reflect UV rays strongly, which shortens the period of protection.

The cooling effect of wind increases the UV light nothing of its risk of sunburn. Even thin clouds hardly reduce UV radiation.

Ozone poor air from the ozone hole can sometimes flow into the temperate latitudes and increase the UV index suddenly strong.

Risks for children

Infants and young children tolerate strong sunlight on exposed skin or eyes not in principle why a protection light on sunny days and during the whole summer season, but fully covering clothing is necessary. These include caps that also cover the neck and sunglasses. An additional umbrella for children provides even better protection.

The Commission on Radiological Protection at the Federal Ministry for the Environment, Nature Conservation and according to reactor safety beckons low exposure to solar radiation still below a reddening of the skin in the long term cancer out: " For the development of malignant melanoma recurring intermittent UV exposures are already in early childhood ( 0-6 years) responsible. These already include isolated suberythemale exposures and even mild and severe sunburns, as they can occur at holidays in sunny regions. "

Treatment

Severe sunburn should be treated by a doctor. The treatment is based on, for example, cooling by moist cold compresses, lotions alba, and anti-inflammatory medications, such as topical steroids Class 2 ( as a cream, lotion or milk, ointments are unsuitable ). Blisters may be sterile opened. In general symptoms steroids in tablet form and NSAIDs such as ibuprofen are prescribed. Ascorbic acid (vitamin C) is - taken at an early stage - useful by its antioxidant effect may be ( Reinhardt 2004). For three weeks, more sun exposure should be avoided completely.

A mild sunburn can be relieved at home and even best with topical cooling, moisturizing lotions, wraps, compresses with cold water, Quark packs or pads (except for milk protein allergy ).

Even with successful treatment, the risk of skin cancer increases with the number of suffered sunburns.

Risks for plants

However, plants can be damaged by increased UV exposure, see eg sunburn in grapes.

Some plants can protect yourself from them. Change in extreme sunshine chlorophyll composition: Chlorophyll connects to carotenoid. Radiated energy is then converted into heat. Does the strength of the sunlight again, the carotenoid disconnects from the chlorophyll and the plant uses the sunlight again for power generation.