Related Experiment Video
Updated: Jul 8, 2025

Precision Implementation of Minimal Erythema Dose MED Testing to Assess Individual Variation in Human Inflammatory Response
Published on: October 3, 2019
Same But Different: An 18-Month Cross-Sectional Study of Cosmetic Procedures in Patients With Skin Phototype I-III
Stephen Williams1, Katherine A McDonald2, Renée A Beach3
1Cummings School of Medicine, University of Calgary, Calgary, Alberta, Canada.
Background:
Patients with darker skin phototypes self-report less facial aging than their lighter-skinned counterparts. However, the association of skin phototype with the type of cosmetic procedures received, is yet to be established in a Canadian context.
Objective:
To compare the pattern of nonsurgical cosmetic procedures performed on people with different Fitzpatrick SPTs.
Materials And Methods:
Cross-sectional study of patient encounters from October 2020-April 2022. Charts and photographs were reviewed and analyzed for age, sex, SPT, and procedure type. Participants were stratified by SPT into 2 cohorts: SPT I-III and SPT IV-VI. SPTs were collapsed into groups based on definitions of "skin of color" (SPT IV-VI) in previous literature.
Results:
We analyzed 350 patients with mean age 43.4, of whom 320 (91%) were female and 30 (9%) were male. The SPT I-III cohort was older (mean age 45 vs 38.5 years, p < .0001) and more frequently underwent neuromodulator injection. The SPT IV-VI cohort more frequently underwent microneedling, platelet-rich plasma, or electrodessication.
Conclusion:
There are distinct patterns of cosmetic procedures performed. The SPT I-III cohort more commonly received procedures to manage facial aging. The SPT IV-VI cohort was younger and more commonly underwent procedures to manage hyperpigmentation.

