Link Identified Between Obesity, Inflammatory Skin Diseases Such as Psoriasis

One of the highest associations between obesity and inflammatory skin conditions is diagnosis of rosacea, according to new findings, although morbid obesity was most highly associated with plaque psoriasis and lichen simplex chronicus.¹

These data resulted from a recent inpatient population study assessing links between obesity and inflammatory skin disease. Siri Choragudi, MD, from Phillip Frost Department of Dermatology and Cutaneous Surgery at the University of Miami Miller School of Medicine, led the team of investigators who authored this analysis.

“Obesity as a risk factor has been predominantly associated with psoriasis and hidradenitis suppurativa in cutaneous pathology, but limited studies have explored the connection to other diseases within the inflammatory skin domain,” Choragudi and colleagues wrote.^1,2

Background and Design Details

The investigators looked into the potential connections between obesity and commonly-occurring inflammatory skin conditions. The analysis included male and female patients aged 18 years and older who were admitted between 2016 and 2019.

They specifically evaluated adult hospital inpatients located throughout the United States, implementing discharge record data drawn from the National Inpatient Sample (NIS). The NIS is a dataset compiled by the Healthcare Cost and Utilization Project (HCUP).

Patient groups with obesity and those labeled as non-obese were included in the analysis. The investigative team noted that this suggests BMI increases can lead to changes in skin physiology and the triggering of immune system changes, ultimately contributing to the development of inflammatory skin conditions given skin barrier function impairments.

The research team identified conditions using ICD-10-CM codes, with obesity and morbid obesity serving as the team’s primary exposure variables. There were 24 inflammatory skin diseases which are often observed among patients that constituted the team’s outcome variables.

The investigators summarized the aforementioned data through the use of survey-weighted and unweighted frequencies. They also calculated prevalence rates with 95% confidence intervals (CIs) and applied multivariable logistic regression models for the purposes of adjusting for factors such as sex, race, age, and additional medical conditions. The team presented their results as odds ratios (ORs).

Major Findings

Prior analyses had demonstrated a link with high BMI and an elevated rosacea risk among women in the US. This was attributed to shared inflammatory mechanisms and connections with metabolic syndrome and other obesity-associated conditions. Aligning with these prior data, the investigative team found that rosacea was 1 condition that demonstrated the strongest association with obesity (OR = 2.26; 95% CI 2.17–2.34).

Another notable observation among the investigators was the the lower odds ratio for rosacea among individuals who were reported to have morbid obesity (OR = 1.52; 95% CI 1.45–1.59). This, they posited, might be the result of differences in the reporting or treatment of comorbid conditions among this population.

When the research team looked at morbid obesity, their analysis demonstrated the strongest link with lichen simplex chronicus (OR = 3.69; 95% CI 3.44–3.96), plaque psoriasis (OR = 5.05; 95% CI 4.77–5.34), and pyoderma gangrenosum (OR = 3.14; 95% CI 2.95–3.34). They attributed their results to the possibility of a dose-response relationship between inflammatory skin conditions and obesity severity.

This, they noted, could be driven by heightened activity of pro-inflammatory cytokines in such individuals. Some examples of these cytokines included interleukin (IL)-6, IL-17, and TNF-α.

“This cross-sectional study is limited by its inability to establish causality,” they wrote. “Potential confounding factors and the lack of longitudinal data further constrain the interpretation of the result…Our findings are also limited to hospitalized inpatients, who may differ from the general population in disease burden and healthcare access.”¹

References

1. ^{Choragudi, S., Andrade, L.F., Mahmoud, O., Yosipovitch, G. and Elman, S.A. (2024), Association of obesity with inflammatory skin disease: An inpatient population study. J Eur Acad Dermatol Venereol. https://doi.org/10.1111/jdv.20440.}
2. ^{Darlenski R, Mihaylova V, Handjieva-Darlenska T. The link between obesity and the skin. Front Nutr. 2022; 10:9.}