Study Highlights Global Prevalence of Patients with Seborrheic Dermatitis

Seborrheic dermatitis may be more prevalent among adults than children, according to new findings, and geographic analyses suggest the disease’s highest prevalence is in South Africa and lowest is within India.¹

These findings were the conclusion of a recent systematic review and meta-analysis, led by Meredith Tyree Polaskey, MS, of the Chicago Medical School at Rosalind Franklin University in Chicago, Illinois. Polaskey et al. noted that despite seborrheic dermatitis’s burden and common occurrence within the clinical area, the condition’s pathogenesis and epidemiology continue to be less well understood.²

The investigators also commented that an overall accurate impression of the disease’s prevalence around the world had remained somewhat elusive. They sought to address this gap in knowledge.

“No comprehensive meta-analysis has been conducted, to our knowledge, that thoroughly addresses the global prevalence of seborrheic dermatitis, especially one that accounts for variations across different settings,” Polaskey and colleagues wrote. “This systematic review with meta-analysis aims to address these gaps by providing a detailed global prevalence estimate of seborrheic dermatitis, examining variations across different sociodemographic factors and settings.”

Study Design

The investigators carried out their systematic review and meta-analysis through a thorough review of current literature on seborrheic dermatitis, with their overall aim being to find out what the data on prevalence of the skin condition has looked like thus far. They implemented Scopus, PubMed, Embase, and the Cochrane Database of Systematic Reviews between the period of June 2022 – October 2023.

The research team would only take into account documents written in the English language, though they placed zero restrictions on data of document publication. For their database searches, the team utilized subject headings as well as keywords associated with the skin disease or with the presence of dandruff.

The investigators first abstract and title screening was done in an independent manner by at least 2 of the trial authors, with this process later being followed by a full-text analysis with the purpose of confirming the studies’ inclusion in the review. Original studies regarding the reporting of seborrheic dermatitis prevalence were included in their searches, whether prospective or retrospective.

The research team would also consider data identified in both the general population and within clinical settings. If there happened to be cases in which there were overlapping sets of information, the most recent dataset would be implemented.

Two predetermined authors would carry out the extraction of their data, highlighting qualities of the studies, research outcomes, and the demographics of study subjects. The team utilized the Joanna Briggs Institute Critical Appraisal Instrument for prevalence studies to determine quality of research.

Conclusions

Overall, the investigators concluded their research with a review of 1,574 articles, including a total of 121 studies that had evaluated a total of 1,260,163 study subjects. They reported that the global prevalence of the skin condition had been shown to be 4.38% (95% CI, 3.58%-5.17%), though they did also find that there had been substantial levels of heterogeneity observed among the study populations (I2 = 99.94%).

In their subgroup analyses, the research team found that adult patients had been shown to have higher prevalence of seborrheic dermatitis (5.64% [95% CI, 4.01%-7.27%]) versus the prevalence observed among neonates (0.23% [95% CI, 0.04%-0.43%]) and children (3.70% [95% CI, 2.69%-4.80%]). The team also noted geographic distinctions among those studied, highlighting the fact that South Africa had the highest level of disease prevalence at 8.82% (95% CI, 3.00%-14.64%) and India maintained the lowest rate of prevalence at 2.62% (95% CI, 1.33%-3.92%).

“These findings underscore the need for further research to better understand the global distribution of seborrheic dermatitis, its variations across diverse populations, and the influence of environmental factors and cultural practices on its prevalence,” they wrote.

References

1. ^{Polaskey MT, Chang CH, Daftary K, Fakhraie S, Miller CH, Chovatiya R. The Global Prevalence of Seborrheic Dermatitis: A Systematic Review and Meta-Analysis. JAMA Dermatol. Published online July 03, 2024. doi:10.1001/jamadermatol.2024.1987.}
2. ^{Wikramanayake TC, Borda LJ, Miteva M, Paus R. Seborrheic dermatitis—looking beyond Malassezia. Exp Dermatol. 2019;28(9):991-1001. doi:10.1111/exd.14006.}