|
Pityriasis alba is a common skin condition mostly occurring in children and usually seen as dry, fine-scaled, pale patches on the face. It is self-limiting and usually only requires use of moisturizer creams. The condition is so named for the fine scaly appearance initially present (pityriasis) and the pallor of the patches that develop (while "alba" is Latin for white, the patches in this condition are not totally depigmented). ==Etiology== Any dermatitis may heal leaving pale skin, as may excessive use of corticosteroid creams used to treat episodes of eczema. The hypopigmentation is due to both reduced activity of melanocytes with fewer and smaller melanosomes.〔Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. ISBN 0-07-138076-0.〕 The condition is most often seen in children between the ages of 3 and 16 years and is more common in males than females. However adults can also suffer from this disease. It may occur more frequently in lighter-skinned patients, but is more apparent in those with darker complexions. Up to a third of US school children may at some stage have this condition. Single-point prevalence studies from India have shown variable rates from 8.4%, to 31%. Other studies have shown prevalence rates in Brazil of 9.9%, Egypt 13.49%, Romania 5.1%, Turkey 12% where higher rates were seen in those with poor socioeconomic conditions, and just 1% in school children in Hong Kong. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pityriasis alba」の詳細全文を読む スポンサード リンク
|