Skin phototype of participants in laser and light treatments of cosmetic dermatologic conditions: A systematic review.

Background: In cosmetic dermatology, lasers and lights treat a variety of hair and skin conditions, including some that disproportionately affect people of color.

Aims: Our systematic review aims to understand the representation of participants with skin phototypes 4-6 in cosmetic dermatologic trials studying laser and light devices.

Methods: A systematic literature search was conducted using search terms "laser," "light," and multiple laser and light subtypes in the PubMed and Web of Science databases. All randomized controlled trials (RCTs) published between January 1, 2010 and October 14, 2021 that studied laser or light devices for cosmetic dermatologic conditions were eligible for inclusion.

Results: Our systematic review included 461 RCTs representing 14 763 participants. Of 345 studies that reported skin phototype, 81.7% (n = 282) included participants of skin phototypes 4-6, but only 27.5% (n = 95) included participants of skin phototypes 5 or 6. This trend of excluding darker skin phototypes persisted when results were stratified by condition, laser of study, study location, journal type, and funding source.

Conclusions: Trials studying lasers and lights for the treatment of cosmetic dermatologic conditions need better representation of skin phototypes 5 and 6.