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Psoriasis Inflammation and Comorbidities
Psoriasis: A Systemic Inflammatory Disease That Is More Than Skin Deep

Released: February 12, 2025

Expiration: February 11, 2026

Linda Stein Gold
Linda Stein Gold, MD
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Key Takeaways
  • Psoriasis is associated with multiple comorbidities that can affect treatment choices

Psoriasis was one of the first of the inflammatory skin diseases for which it was demonstrated that the disease was more than just skin deep. Rather than only affecting the skin, psoriasis is a chronic systemic inflammatory disease with involvement of multiple organ systems.

Psoriatic Arthritis
Psoriatic arthritis is the most common comorbidity with a prevalence of up to 30% among people with psoriasis, although it is generally underdiagnosed. The onset of arthritis is often 7 to 10 years after the onset of skin lesions. Symptoms of psoriatic arthritis most commonly arise in middle age (30-50 years of age), with infrequent later onset in the seventh decade of life associated with more severe disease.

Areas of psoriasis that have been associated with increased risk of developing psoriatic arthritis include nail, scalp, and intergluteal involvement. Early initiation of therapy may decrease joint damage and improve long-term outcomes. 

Cardiovascular Disease and Metabolic Syndrome
Cardiovascular disease is another important comorbidity associated with psoriasis. Evidence has suggested that patients with more severe disease are at increased risk of cardiovascular death. The highest relative risk is in younger patients with severe disease.

In addition to cardiovascular disease, metabolic syndrome (of which cardiovascular disease is a component) has been clearly linked to psoriasis. The main components of metabolic syndrome include obesity, high blood pressure, high blood triglycerides, low levels of HDL cholesterol and insulin resistance.

Nonalcoholic fatty liver disease (now known as metabolic dysfunction–associated fatty liver disease) is also more common in patients with psoriasis.

Mental Health
Psoriasis can wreak havoc on patients’ physical and emotional lives. Patients are at high risk for mental health issues including depression and anxiety. Up to 20% of patients with psoriasis have depressive symptoms.

It is thought that systemic inflammation may play a role in the development of depression, potentially mediated through interleukin (IL)-6. Levels of IL-6 are elevated in psoriasis, and it has been associated with progression of psychiatric conditions. Clinical studies have demonstrated that targeting psoriatic disease burden with biologic therapies reduces depressive and anxiety symptoms directly related to psoriasis.

Inflammatory Bowel Disease
Psoriasis—and psoriatic arthritis—also appear to be associated with Crohn’s disease and ulcerative colitis, especially in women. When treating people with psoriasis and IBD, significant caution should be given to the IL-17 inhibitor class of biologics because of the paradoxical risk of developing or exacerbating Crohn’s disease and ulcerative colitis.

Malignancy
The risk of cancer associated with psoriasis has been extensively studied. A recent study including approximately 200,000 people with psoriasis found a slightly increased incidence of lymphoma, lung cancer, and nonmelanoma skin cancer. There was no increase in the incidence of leukemia or breast, colon, or prostate cancers identified among those with psoriasis.

Generally, patients with a history of malignancy have been excluded from most clinical trials, so data on outcomes from biologic psoriasis therapies in people with a previous malignancy are scarce. An analysis of patients with psoriasis and prior malignancies who were treated with biologic agents at a single center (n = 37) or identified through a literature search (n = 38) found treatment to be safe with no treatment-related cases of disease progression. Based on this analysis, the use of biologic therapies against TNF alpha, IL-17, IL-23, and IL-12 for psoriasis treatment in people with previous malignancies appears to be safe. Nonbiologic therapies including psoralen plus ultraviolet A  and traditional systemic therapies may increase the risk of skin cancers.

Holistic Approach to Care
Given the multisystemic nature of psoriasis and the large body of data demonstrating increased rates of a variety of proinflammatory comorbidities among individuals with vs without psoriasis, it is best to take a holistic approach to providing care for patients with psoriasis, recognizing that the disease involves ongoing systemic inflammation.

As frontline care providers for people with psoriasis, dermatologists can play an important role in facilitating broader and more comprehensive disease management by educating their patients on the increased risk of key comorbidities, advising them on lifestyle modifications (eg, nutrition, exercise) that may mitigate that risk, and ensuring that they are linked with a primary care provider who is knowledgeable about the systemic effects of psoriasis and can implement recommended assessments and referrals for additional specialist care when needed.

Your Thoughts?
How do you approach the common comorbidities of psoriasis when providing care for your patients? Do you ensure that all of your patients with psoriasis are engaged with a primary care provider for regular comorbidity screenings? Get involved in the discussion by posting a comment.