UV Radiation and Photosensitivity: Safeguarding Your Skin

UVR is a combination of visible light and invisible light called ultraviolet radiation. UVR is responsible for, but it can also cause. UVR can be divided into UVB (short-wavelength rays which cause sunburns and tanning) and UVA. Patients may be more sensitive to certain types of sunlight. Patients can be sensitive to UVB, UVA, or visible light only or to a broader range of radiation. UVA is the most common cause of photosensitivity.

Photosensitizers are drugs, foods, or chemicals that increase the photosensitivity of an organism. It can be an unwanted side effect from many drugs or it could be a desirable effect for photodynamic treatment of tumors. A photosensitizer in photochemistry is a compound that undergoes photoexcitation easily and transfers the energy to other molecules. This makes the reaction mixture more susceptible to light.

Certain drugs and food groups do not mix with ultraviolet light, whether it is a natural or artificial source. The list below includes drugs, food, and other substances that could cause your skin to be more sensitive to ultraviolet light.

Topical can be classified in two broad categories based on their mechanisms of action: chemical absorbers or physical blockers. Chemical absorbers absorb ultraviolet (UV) rays. They can also be differentiated based on the type of radiation that they absorb: UVA, UVB or both UVA, and UVB. Physical blockers reflect or scatter the UV radiation. Some chemical absorbers can degrade if exposed to sunlight. Photo-unstable, and may not perform to expectations. These chemicals are often mixed with other substances that improve the stability of the sunscreen. These chemicals are commonly mixed with other absorbers, because they are photostabile and stop the formula from breaking down in the sun. e.g. Benzophenones, Para-aminobenzoic acid (PABA), Cinnamates, Salicylates.

Musk,6-methylcoumarin. Only a few fragrances can cause allergies in people who are sensitive. Some paints, metalworking fluids, and cutting fluids contain fragrances that mask offensive odours. Air conditioning can also circulate fragrances.

Phototests can confirm photosensitivity. Artificial light is shone onto small patches of skin in order to determine if the rash or sunburn can be reproduced. The photopatch test can be used to determine if a certain item has caused a reaction in the skin.

The UV Index (UVI), developed by WHO, UN Environment Program, and World Meteorological Organization, is an international standard for UV measurements. The UV index is intended to alert people to the possibility of adverse health effects, and encourage them to take precautions. The UVI value is a measure of the risk for skin and eye damage. It also indicates the time required for the harm to occur. When the UV index is 3 or higher, sun protection should be worn.