Abstract
Seborrheic dermatitis (SD), a chronic inflammatory skin condition consisting of itchy, red patches with greasy scales, has been linked to numerous systemic conditions. This review evaluates comorbidities and lifestyle factors that are associated with seborrheic dermatitis. A literary search was conducted in August 2024 using EMBASE, PubMed, and Medline Industries, and evaluated according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following results were found from this search. Diet may play a role in seborrheic dermatitis as participants with a diet high in simple carbohydrates, high in vitamin D, and low in iron have a higher instance of disease. Femoral cartilage thickness (FCT), a potential indicator of early osteoarthritis, was greater in patients with SD than in controls and was positively correlated with increasing SD severity. SD has also been associated with chronic diseases. Nearly half of Parkinson's disease (PD) patients in one study also had SD. As the severity of Parkinson's disease symptoms increases, the development of SD was observed to occur at a much higher rate, with the burden of SD positively correlated to the severity of PD symptoms. In one cross-sectional study of patients with SD, the most common systemic comorbidities were hypertension and diabetes, however, this finding was not statistically significant. Another study found that obesity was common amongst patients with SD, but this finding was also not significant. Visceral protein levels and height, however, were positively associated with increased SD disease severity. Metabolic syndrome and lower high-density lipoprotein (HDL) and triglycerides have been shown to be associated with more severe SD. Osteoporosis had a higher prevalence and faster disease progression in individuals with comorbid SD than in controls. Around 16% of individuals with psychiatric disorders, such as schizophrenia, bipolar disorder, and major depressive disorder, were found to have SD. HIV is a disease with higher incidence of SD, although the prevalence of comorbid SD may be decreasing as the use of antiretroviral therapy increases. These associations highlight the complex nature of seborrheic dermatitis and underscore the necessity for further research to better understand these relationships and improve disease management.