Polymorphic light eruption: prevalence in Australia and England.

The prevalence and clinical characteristics of polymorphic light eruption were assessed by a questionnaire survey of 172, 196 and 182 subjects in Perth, Ballarat and London, respectively. The prevalence was 5.2% in Perth (latitude 32 degrees), 3.6% in Ballarat (37.5 degrees) and 14.8% in London (51.5 degrees). The age distribution (mostly first three decades) and male:female ratio (1:3) was similar for affected individuals in all three areas. Development of tolerance during the summer was more common in Perth (66.7%) and Ballarat (71.4%) than in London (40.7%).