Polymorphic light eruption: prevalence in Australia and England

Area of Science:

• Dermatology
• Photobiology
• Epidemiology

Background:

• Polymorphic light eruption (PLE) is a common photodermatosis.
• Geographical variations in PLE prevalence are suspected but not well-documented.
• Understanding PLE's clinical characteristics and geographical distribution is crucial for public health.

Purpose of the Study:

• To assess the prevalence and clinical characteristics of polymorphic light eruption (PLE).
• To compare PLE prevalence across different latitudes: Perth (32°), Ballarat (37.5°), and London (51.5°).
• To investigate factors influencing PLE, such as age, sex, and development of tolerance.

Main Methods:

• A questionnaire survey was conducted.
• Participants included 172 subjects in Perth, 196 in Ballarat, and 182 in London.
• Data collected focused on PLE prevalence, demographics, and seasonal tolerance.

Main Results:

• PLE prevalence was 5.2% in Perth, 3.6% in Ballarat, and 14.8% in London.
• Affected individuals across all sites showed similar age distributions (primarily first three decades) and a 1:3 male:female ratio.
• Seasonal tolerance development was more frequent in lower latitudes: 66.7% in Perth and 71.4% in Ballarat, compared to 40.7% in London.

Conclusions:

• PLE prevalence is significantly higher at higher latitudes (London) compared to lower latitudes (Perth, Ballarat).
• Clinical characteristics and demographics of PLE are consistent across different geographical locations.
• Latitude appears to influence the development of summer tolerance in individuals with PLE.