Indoor simulation of polymorphic light eruption using a UVA/UVB solar simulator and prevention by a well-balanced UVA/UVB sunscreen

Abstract

Objective/Methods: The efficacy of a sunscreen product in preventing polymorphic light eruption (PLE) was evaluated using a light source to deliver increasing doses of ultraviolet A (UVA) and ultraviolet B (UVB) radiation to 18 PLE-susceptible subjects over a 5-day period. The UVA-UVB ratio delivered by the artificial source was similar to that in natural sunlight. The intraindividual double-blind evaluation was performed against a positive PLE control where the skin was protected by a low-SPF sunscreen product.

Results: After five exposures which mimicked a natural outdoor sun exposure, all subjects developed typical PLE symptoms in the positive control areas, whereas only one subject developed symptoms in the area protected by a UVA/UVB sunscreen.

Conclusion: A sunscreen providing high-level protection against UVA as well as UVB effectively prevented PLE under experimental conditions.

Key Words:

• Polymorphic light eruption
• Sunscreens
• UVA protection