It occurs in mainly children and adolescents of all races, particularly people with dark skin. The worldwide prevalence is 5% in children, with boys and girls affected equally. adults can also suffer from this disease. 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. In 1963, one school health clinic reported features of<unk>  in two fifths of their children.
Pityriasis alba
Alopecia mucinosa
Pityriasis rosea
Phytophotodermatitis
Ichthyosis acquisita
Pityriasis rubra pilaris
Pityriasis amiantacea
Alopecia universalis