Global Burden and Demographic Decomposition of Seborrheic Dermatitis, 1990–2023: A Secondary Analysis of GBD 2023 Estimates

Ying Wang, Ning Chen, Han HanDepartment of Dermatology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430014, People’s Republic of China*These authors contributed equally to this workCorrespondence: Han Han, Department of Dermatology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430014, People’s Republic of China, Email 1457579841@qq.comBackground: Case counts of seborrheic dermatitis have progressively increased, which may reflect population growth, changing age structure, and changing age-specific rates. We quantified these components within a consistent Global Burden of Disease (GBD) 2023 series.Methods: We analyzed incidence, prevalence, and disability-adjusted life-years (DALYs) for 1990– 2023 globally and by region, sex, age, and Socio-demographic Index group. Symmetric Das Gupta decomposition partitioned changes in global counts into population-size, age-structure, and age-specific-rate components. Replacement-order and age-group sensitivities assessed component directions. Deterministic scenarios combined fixed 2023 age-specific rates with each UN World Population Prospects 2024 variant’s age-specific populations through 2040.Results: In 2023, modeled incident cases totaled 183.94 million (95% uncertainty interval 170.17– 197.03 million), prevalent cases 26.73 million (25.14– 28.48 million), and DALYs 358,629 (206,994– 558,580), increasing by 50.7%, 62.3%, and 61.3% from 1990. Age-standardized rates changed by 0.31%, 0.23%, and 0.38%, respectively. Population growth accounted for 100.8%, 85.1%, and 86.2% of the net increases. Age-structure change contributed − 1.7% to incident cases but +14.2% to prevalent cases and +12.8% to DALYs; age-specific-rate changes contributed 0.9%, 0.6%, and 1.0%. Age-structure component directions persisted across replacement orders and ten-year age grouping. The fixed-rate Medium scenario yielded 204.18 million incident cases in 2040.Conclusion: Within GBD 2023 point estimates, population growth was the main accounting component of increasing absolute burden. Age-structure change contributed in opposite directions to incidence versus prevalence and DALYs. These descriptive results support reporting counts alongside standardized rates; they do not establish individual disease duration or biological mechanisms.Keywords: seborrheic dermatitis, global burden of disease, incidence, prevalence, disability-adjusted life-years, demographic decomposition