Impact of seborrheic dermatitis on osteoporosis risk: A population‐based cohort study

Skin Disorders and Osteoporosis: Unraveling the Interplay Between Vitamin D, Microbiota, and Epigenetics Within the Skin-Bone Axis

Growing scientific evidence suggests a strong interconnection between inflammatory skin diseases and osteoporosis (OP), a systemic condition characterized by decreased bone density and structural fragility. These conditions seem to share common pathophysiological mechanisms, including immune dysregulation, chronic inflammation, and vitamin D deficiency, which play a crucial role in both skin and bone health. Additionally, the roles of gut microbiota (GM) and epigenetic regulation via microRNAs (miRNAs) emerge as key elements influencing the progression of both conditions. This review aims to examine the skin-bone axis, exploring how factors such as vitamin D, GM, and miRNAs interact in a subtle pathophysiological interplay driving skin inflammation and immune-metabolic bone alterations. Recent research suggests that combined therapeutic approaches-including vitamin D supplementation, targeted microbiota interventions, and miRNA-based therapies-could be promising strategies for managing comorbid inflammatory skin diseases and OP. This perspective highlights the need for multidisciplinary approaches in the clinical management of conditions related to the skin-bone axis.

Exploring the Impact of Vitamin D and Zinc Deficiencies on Seborrheic Dermatitis: A Comparative Study

Background and Aims

Seborrheic dermatitis (SD) is a chronic inflammatory skin condition that affects patients' quality of life. Emerging evidence suggests that vitamin and mineral deficiencies may contribute to its progression, although the exact etiology remains unclear.

Objective

This case-control study assessed the serum levels of vitamin D and zinc in SD patients compared to a healthy control group, with a focus on how these deficiencies relate to disease severity.

Methods

A total of 71 SD patients and 71 healthy controls participated, providing demographic data and blood samples. Disease severity was evaluated using the SEDASI scoring system. Serum vitamin D and zinc levels were measured using ELISA and photometric methods, respectively. Statistical analysis was performed using t-tests and chi-square tests in SPSS 24, with groups matched for demographic variables (p > 0.05).

Results

Findings revealed no significant difference in vitamin D levels between SD patients and the control group (p = 0.066). However, zinc levels were notably lower in the SD group (p = 0.001). Additionally, vitamin D levels were inversely related to the severity of SD (p = 0.022), while no correlation was found between zinc levels and disease severity (p = 0.664).

Conclusion

Zinc deficiency appears to play a role in SD pathogenesis, while lower vitamin D levels are associated with increased disease severity. These findings highlight the need for further research into the potential therapeutic role of nutrient supplementation in managing SD.

Exploring Systemic Comorbidities and Lifestyle Factors Associated With Seborrheic Dermatitis: A Scoping Review

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.

Is seborrheic dermatitis associated with early-stage osteoarthritis?

Seborrheic dermatitis (SD) and osteoarthritis involve similar factors in their pathogenesis. Both of these diseases are associated with an increased frequency of metabolic syndrome and underlying systemic inflammation. This study evaluated the thickness of the distal femoral cartilage using ultrasonography in patients with SD. The study enrolled 60 patients with SD (19 females and 41 males, mean age: 34.07 ± 12.56 years) and 60 controls matched for age and sex (20 females and 40 males, mean age: 35.08 ± 12.78 years). Ultrasonography was used to measure the distal femoral cartilage thickness (FCT) of the right medial condyle, right lateral condyle, right intercondylar area, left medial condyle, left lateral condyle, and left intercondylar area. FCT values at all points were significantly higher in patients with SD than in the controls (P < .05). Further, all FCT values were significantly higher in patients with moderate SD than in those with mild SD (P < .001). A strong positive correlation was observed between disease severity and FCT measured at right medial condyle (r = .7, P < .001), right lateral condyle (r = .749, P < .001), right intercondylar area (r = .79, P < .001), left medial condyle (r = .624, P < .001), and left intercondylar area (r = .703, P < .001). Further, a moderately positive correlation was observed between disease severity and FCT measured at left lateral condyle (r = .581, P < .001). Increased FCT in patients with SD might be an early indicator of osteoarthritis. However, further studies, especially those evaluating older patients with SD, are required to support our findings.

Improvement in Cutaneous Conditions Can Benefit Some Health Conditions in the Elderly

As we are aging, a number of cutaneous and extracutaneous disorders will be developed. Although the pathogenesis of these aging-associated disorders is not clear yet, abnormalities in the skin are linked to some aging-associated disorders at least to some extent. Inflammatory dermatoses such as psoriasis and atopic dermatitis predispose to the development of cardiovascular diseases, obesity and type 2 diabetes. In addition, both chronologically aged skin and individuals with some aging-associated systemic conditions display altered epidermal function, such as reduced stratum corneum hydration levels, which can provoke cutaneous inflammation. Because aged skin exhibits higher expression levels of inflammatory cytokines, which play a pathogenic role in a variety of aging-associated health condition, the association of the skin with some aging-associated disorders is likely mediated by inflammation. This postulation is supported by the evidence that improvement in either epidermal function or inflammatory dermatoses can mitigate some aging-associated disorders such as mild cognitive impairment and insulin sensitivity. This perspective discusses the association of the skin with aging-associated disorders and highlights the potential of improvement in cutaneous conditions in the management of some health conditions in the elderly.