Why Residual Inflammation Matters in Psoriasis Care

Credit: Adobe Stock/SNAB

Psoriasis isn’t just a skin condition — it’s also linked to increased risk for heart disease. That’s because psoriasis involves systemic (whole-body) inflammation, which plays a key role in both skin flare-ups and heart health. Even when psoriasis seems under control on the outside, experts emphasize that inflammation may still be simmering on the inside. This is known as residual inflammation.

Chronic inflammation has been associated with several diseases that increase disability and mortality, including cardiovascular disease, diabetes, nonalcoholic fatty liver disease, chronic kidney disease, autoimmune conditions and neurodegenerative disorders.

Previous research has shown that residual inflammatory risk — first discovered among patients with high-risk atherosclerosis who had inflammation despite receiving optimal medical therapy — is a stronger indicator of future cardiovascular events than cholesterol.

Recently, a team of investigators examined this issue in more detail among patients with psoriasis who had been successfully treated with biologic therapy and had clear or nearly clear skin (measured by a Psoriasis Area Severity Index [PASI] score of 2 or less). The international study included 209 patients with moderate to severe psoriasis from Spain, the U.S. and Sweden.

“Psoriasis, with its systemic inflammatory nature, high atherosclerosis burden and frequent use of biologic drugs, could provide a valuable framework for studying residual inflammation,” they wrote.

Despite the excellent skin response among participants, more than one-third of patients (36.3%) still had high levels of inflammation in their blood, measured by a marker called high-sensitivity CRP (hs-CRP ≥ 2 milligrams per liter).

Findings showed that residual inflammation was more common in the following:

• People with higher body mass index (BMI)
• Those with metabolic-related fatty liver disease
• People who had higher levels of inflammation before starting treatment
• Those with more visceral (deep belly) fat
• Women, who were more likely to show signs of residual inflammation than men and are often more likely to be diagnosed with an autoimmune disease

Investigators noted that since all participants had moderate to severe disease and most were male adults, these results may not be generalizable to other populations, such as those with milder psoriasis. However, the obesity rates were consistent with previously reported data on obesity in psoriasis. Other limitations to consider were the short follow-up period — which prevented the team from determining how biologic treatments affected inflammation in the long run — and not including a group of patients who weren’t receiving biologic treatments.

Despite this, the study offered valuable insights into how inflammation can persist in people with psoriasis, even when their skin appears clear after biologic treatment. One of its key strengths was that it included patients from three different countries — making the findings more relevant to people around the world. Another strength was that it involved patients using nearly all the major biologic medications available for psoriasis. This helps make the results more useful for people currently receiving or considering these treatments.

Essentially, the findings highlight that if a patient’s psoriasis looks well managed on the outside, underlying inflammation may still be affecting their overall health, particularly in the heart and liver.

“Further studies are needed to confirm these findings and better understand the long-term implications for patient management,” investigators wrote. “Addressing residual inflammation in patients with psoriasis could ultimately lead to more comprehensive treatment strategies aimed at reducing both skin and systemic inflammation.”