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The toxic effects of UV from natural sunlight and therapeutic artificial lamps are a major concern for human health. Skin surface lipids, including unsaturated lipids such as squalene , sebaleic acid, linoleic acid , and cholesterol can be a subject of oxidation by singlet oxygen and ozone as well as free radicals.
Solar urticaria is an immunoglobulin E-mediated hypersensitivity that can be introduced through primary or secondary factors, or induced by exogenous photosensitization. [15] [16] Primary SU is believed to be a type I hypersensitivity (a mild to severe reaction to an antigen including anaphylaxis) in which an antigen, or substance provoking an immune response, is "induced by UV or visible ...
Polymorphous light eruption (PLE) presents with itchy red small bumps on sun-exposed skin, particularly face, neck, forearms and legs. [1] It generally appears 30 minutes to a few hours after sun exposure and may last between one and 14 days. [3] The bumps may become small blisters or plaques and may appear bloody, [3] often healing with ...
Sun poisoning is an extreme case of sunburn in which ultraviolet radiation inflames the skin. Bela Chatwin, 21, from Utah, had swollen up so much that her own sister didn't recognise her.
Given the causal relationship between sun exposure and AK growth, they often appear on a background of sun-damaged skin and in areas that are commonly sun-exposed, such as the face, ears, neck, scalp, chest, backs of hands, forearms, or lips. Because sun exposure is rarely limited to a small area, most people who have an AK have more than one. [10]
The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a requisite for vitamin D 3 synthesis and a mutagen. Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun. [ 3 ] A photon starting at the center of the Sun and changing direction every time it encounters a charged particle ...
Excessive exposure to ultraviolet rays has negative health effects, including sunburn. Some people tan or sunburn more easily than others. This may be the result of different skin types and natural skin color, and these may be a result of genetics. [2] [3] The term "tanning" has a cultural origin, arising from the color tan.
Some drugs have a photosensitizing effect. Properties of natural or artificial light that may abnormally affect people include: Timing of light (upset of normal circadian rhythms, seasonal affective disorder, sleep disorders) Intensity of light (photophobia, sunburn, skin cancer) [1] [2] [3] Wavelength of light (in lupus, urticaria)