Search results
Results from the WOW.Com Content Network
Light sensitivity or photosensitivity refers to a notable or increased reactivity to light. Apart from vision , human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury.
Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light. In medicine, the term is principally used for abnormal reactions of the skin, and two types are distinguished, photoallergy and phototoxicity .
Phototoxins are toxins that can cause allergic reactions in particularly susceptible individuals and which can cause dangerous photosensitivity in a much broader range of subjects. Phototoxins are common in: a variety of plants (including food plants where they may be a biological defence): many citruses contain essential oils that are ...
It is a type of photosensitivity. [1] [2] The skin response resembles an exaggerated sunburn. The involved chemical may enter into the skin by topical administration, or it may reach the skin via systemic circulation following ingestion or parenteral administration. The chemical needs to be "photoactive," which means that when it absorbs light ...
Photosensitivity is also found in some of the porphyrias. Nearly all cases of porphyria cutanea tarda [ 18 ] exhibit blister formation on the skin within 2–4 days of light exposure. Variegate porphyria [ 19 ] and hereditary coproporphyria [ 20 ] can also exhibit symptoms of light-induced blisters.
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 ...
Studies have shown that shade can reduce heat stress on the human body between 25% and 35% throughout the day. Shaded areas can be 20 to 45 degrees Fahrenheit cooler than surfaces without it ...
Cockayne syndrome (CS), also called Neill-Dingwall syndrome, is a rare and fatal autosomal recessive neurodegenerative disorder characterized by growth failure, impaired development of the nervous system, abnormal sensitivity to sunlight (photosensitivity), eye disorders and premature aging.