674 Racial differences in melasma risk factors and treatment patterns

Melasma is a common acquired hyperpigmentation disorder disproportionately affecting women of color. Though its cause remains unknown, several predisposing risk factors have been identified. Our investigation sought to better define racial and ethnic differences in factors, treatment patterns, incidence melasma the US through large case-control analysis. We queried TriNetX database representing 40 healthcare organizations for adults diagnosed with using ICD-10 code L81.1 (n=22,110). Controls were matched by age, sex race. explored gravidity, hyperthyroidism, exposure exogenous hormones hyperpigmenting drugs as factors. also analyzed topical steroids retinoids, hydroquinone (HQ), tranexamic acid (TA) azelaic acid. Median age diagnosis was lowest Whites (41.5) highest Blacks (54.1). Hispanics had increased hormone (both 19%), while (46%). Asians significantly compared across all factors: gravidity history (OR=1.4, p=0.001 OR=1.4, p<0.001), hyperthyroidism (OR=1.8, p=0.005 OR=2.4, (OR=2.6, p<0.001 OR=2.6, P<0.001) (OR=2.8, OR=2.2, p<0.001). Notably, races, stronger factor than history. Hyperpigmenting significant races raising possibility drug-induced contributing melasma. For therapy, most likely (34%) least (26%) receive tretinoin. HQ TA rates at 30% 2.5% respectively. Overall, our results indicate melasma, due various patterns.