Acne incidence and severity in transgender adults: A multi-center cohort study

Summary: Abstract Body: Gender-affirming hormone therapy affects acne incidence in transgender persons, but epidemiologic data are scant. This study aimed to examine acne incidence in a validated cohort of transgender adults enrolled in Kaiser Permanente Northern and Southern California, Georgia, and Mid-Atlantic States. Transgender adults were followed from first documented transgender status (index date) to incident acne (≥1 ICD code) or moderate-to-severe acne (isotretinoin or ≥30 days oral antibiotics post-acne) in 1/2006–6/2024. Up to 10 cisgender male (CM) and 10 cisgender female (CF) adults were matched to each transgender adult by age, race/ethnicity, enrollment year, and site. Incidence rates were compared using negative binomial regression. 11,029 TM adults (mean age (SD) 28.7 (9.6) years) and 9,614 TF adults (mean age (SD) 33.5 (13.2) years) were matched with 149,260 CM and 150,175 CF adults. Mean (SD) follow-up time in TM and TF adults were 4.3 (3.4) and 5.2 (4.1) years. Incident acne rates were higher in TM adults than CM adults (Incidence rate ratio [IRR]=12.6, 95% CI 11.0–14.5; Incidence rates [IR]=29.7 vs 6.1) and CF adults (IRR=2.1, 1.9–2.4; IR=29.8 vs 19.0); and higher in TF adults than CM adults (IRR=3.5, 2.9–4.4; IR=9.8 vs 4.8), but lower than CF adults (IRR=0.6, 0.5–0.7; IR=9.9 vs 14.6). Incident moderate-to-severe acne rates were higher in TM adults than CM adults (IRR=51.6, 34.8–76.4; IR=11.4 vs 2.1) and CF adults (IRR=4.3, 3.2–5.9; IR=11.4 vs 5.0); and higher in TF adults than CM adults (IRR=2.3, 1.4–3.8; IR=2.3 vs 1.5), but lower than CF adults (IRR=0.4, 0.2–0.7; IR=2.3 vs 3.6). This study relied on clinician diagnosis and might not generalize to uninsured patients. Acne more commonly affects transgender adults than cisgender adults. Clinicians should proactively evaluate and manage acne and future research should examine long-term acne outcomes in transgender adults. Courtney A. Smith¹, Oumaima Kaabi², Ketki Joshi¹, Suephy Chen³, Vin Tangpricha⁴, Michael Goodman², Howa Yeung¹ 1. Dermatology, Emory University, Atlanta, GA, United States. 2. Emory University Department of Epidemiology, Atlanta, GA, United States. 3. Dermatology, Duke University, Durham, NC, United States. 4. Endocrinology, Emory University, Atlanta, GA, United States. Minoritized Populations and Health Disparities Research