INDIVIDUAL ARTICLE: Psoriasis Is a Systemic Disease

Obesity in the US is a significant public health concern. According to the CDC, 22 states have an adult obesity prevalence of 35 percent or higher.¹ Obesity is a proinflammatory state and is associated with increased risk for cardiovascular disease, diabetes mellitus, certain malignancies, musculoskeletal diseases, and liver disease, as well as psychiatric effects and decreased life expectancy.²

The risks of obesity are not unlike those of psoriatic disease. Psoriasis and psoriatic arthritis are associated with increased risk for cardiovascular disease, hypertension, metabolic disease, and liver disease.³ The risk for systemic comorbidities appears to increase with more severe psoriatic disease.⁴ Psoriasis and obesity are proinflammatory diseases that frequently co-exist and may have cross-directional influence.⁵ Therefore, their concomitant presentation can complicate treatment of psoriatic disease. 

In the dermatology clinic, treatment of moderate-to-severe psoriasis with systemic anti-inflammatory agents is believed to modulate the systemic inflammatory effects of psoriasis.⁶ In short, providing effective treatment of skin and joint disease may reduce overall inflammation in the body and improve the patient’s health status.

As discussed in the pages ahead, obesity presents a complication to psoriasis management, since it appears that some targeted psoriasis treatments are less effective in patients with higher Body Mass Index (BMI).⁷ However, the IL-17R antagonist brodalumab has both clinical trial and real-world data that show consistent efficacy across BMI categories.⁸ 

In addition to systemic treatment, lifestyle modification is an important aspect of management of psoriasis in the obese patient. Interestingly, data show that caloric restriction, irrespective of weight loss, may have beneficial effects on psoriasis.⁹ The emergence of GLP-1 receptor agonists for weight reduction may also offer an option for reducing BMI in overweight psoriasis patients. Controlled research is needed, but case reports suggest these agents may have a direct effect on psoriasis.¹⁰

The management of each individual patient with psoriasis requires the thoughtful assessment of a variety of considerations, including lifestyle factors, among others. For obese patients with psoriasis, it is increasingly important to consider the impact of excess weight on treatment efficacy. Treatments that are provided in a weight-based dose may warrant consideration. However, the potential benefit of brodalumab, which has been shown effective across a range of BMIs, should not be overlooked.

We should always remember "Psoriasis is a complex systemic disease"!

Leon H. Kircik MD

Icahn School of Medicine at Mount Sinai, New York, NY; Indiana University School of Medicine, Indianapolis, IN; Physicians Skin Care, PLLC Louisville, KY; DermResearch, PLLC Louisville, KY; Skin Sciences, PLLC Louisville, KY