Effects of hormonal treatment on dermatological outcome in transgender people: a multicentric prospective study (ENIGI)

PURPOSE: The aim of our study was to assess dermatological changes in transgender people after the start of gender-affirming hormonal treatment (GAHT) and to investigate whether various hormonal preparations differently affect dermatological changes in trans AFAB (assigned female at birth) people. METHODS: In a multicenter prospective study, 484 participants (193 assigned male at birth/AMAB and 291 AFAB) were evaluated at baseline (T0), 6 (T1) and 12 months (T2) after the start of GAHT. Hair growth was assessed by the Ferriman–Gallwey (FG) score, acne by the Global Acne Grading Scale (GAGS), and alopecia by the Norwood Hamilton (NH) score. RESULTS: In AFAB people, a significant increase in FG score and NH grade was observed across time, as well as in GAGS score in a subsample of 71 individuals (p < 0.001). Testosterone (T) undecanoate and esters showed a higher increase in hair distribution at T2 vs. T1 as compared to T gel (p < 0.01). T esters showed a significantly higher impact in GAGS score modifications at T1 and at T2 vs. T0 compared to T gel (p = 0.021 and p = 0.003, respectively). In trans AMAB people, a significant decrease of FG score was observed across time (p < 0.001), although 51.3% of individuals still reported an FG score higher than eight after 12 months. CONCLUSION: T treatment increased hair growth, acne and alopecia prevalence in AFAB people, with T undecanoate and esters influencing hair growth more than T gel. Opposite dermatological changes were observed in AMAB people.