Comorbidities with psoriasis

Date of preparation: December 2024

Comorbidities with psoriasis

Psoriasis (Pso) is a systemic disease associated with chronic inflammation throughout the body.1 As a result, psoriasis is associated with numerous comorbidities, such as psoriatic arthritis (PsA), making patient management challenging. As represented in the image below, these comorbidities may be displayed in varying proportions across patients with Pso and PsA.

Figure 1: Overview of comorbidities with psoriasis or psoriatic arthritis^1-22

* In patients with Pso only and no concurrent PsA. 

† Data are from the Understanding Psoriatic Disease Leveraging Insights for Treatment (UPLIFT) survey, a cross-sectional, quantitative web-based survey, in 2,550 patients with Pso. 

‡ Subclinical enthesitis.

Psoriatic arthritis

Psoriatic arthritis is an inflammatory arthritis that occurs in 6%–42% of patients with psoriasis.^7,23,24

Figure 2: Most patients present with psoriasis before PsA^7,23,24

* This was a non-interventional, cross-sectional study to evaluate the prevalence and clinical patterns of PsA in Indian patients with Pso (N=1,149) according to the ClASsification for Psoriatic ARthritis (CASPAR) criteria.

Peak incidence of PsA occurs between ages 30–50 years and is characterised by oedema (swelling), and pain and stiffness of the joints, ligaments and tendons (enthesitis and dactylitis).²⁵ Up to 30% of patients with PsA present dactylitis or ’sausage digit’, which is the inflammation of an entire digit.²⁶ 

According to the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) treatment recommendations for the management of PsA, there are multiple domains involved, including:²⁷ 

• Peripheral arthritis 
• Axial disease 
• Enthesitis 
• Dactylitis 
• Psoriasis 
• Nail disease 
• Inflammatory bowel disease 
• Uveitis 

It is essential that patients with psoriasis are screened for PsA at each visit to their dermatologist to enable early diagnosis of PsA and limit permanent joint destruction.¹ See Progression to PsA for more information.

Uveitis

Uveitis is caused by inflammation of the tissues of the uveal tract, and symptoms include pain, redness of the eye, floaters and blind spots.¹³ While uveitis occurs in 7–20% of patients with psoriasis, incidence tends to be higher in those suffering from both psoriasis and psoriatic arthritis or PsA alone,13 and prevalence is higher in older populations and varies across ethnicities.²⁸

Patients with psoriasis and redness of the eye (with or without pain), blurred vision and photosensitivity should be referred to an ophthalmologist.¹

Inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterised by a chronic inflammation of the gastrointestinal tract that leads to a dysregulation of the intestinal homeostasis.²⁹ Symptoms of IBD include bloody diarrhoea, urgency, tenesmus (a persistent and painful desire to evacuate the bowel, despite having an empty rectum), abdominal pain and weight loss.^30–32 

IBD can be subdivided into distinct phenotypes of ulcerative colitis (UC) and Crohn’s disease (CD):^29,33 

• UC only affects the large intestine causing inflammation continuously and proximally from the anus, affecting mucosal and submucosal layers. 
• CD causes discontinuous patchy inflammation and is transmural (affects the full thickness of the bowel wall) and can affect any part of the gut. 

Dermatologists should refer patients with signs and symptoms of IBD for assessment by their primary care provider or gastroenterologist.¹ Treatment with TNF inhibitors (used for the treatment of psoriasis) can cause new-onset psoriasiform eruptions in patients with IBD.1 If this occurs, treatment of the bowels and skin should be individualised.¹

Cardiovascular disease

Being a systemic disease, psoriasis is associated with numerous metabolic syndromes that contribute to cardiovascular disease, including obesity, hypertension, type 2 diabetes and dyslipidaemia. Together, they contribute to an increased risk of myocardial infarction, especially in those with severe disease.¹ 

Dermatologists should ensure that patients with psoriasis are aware of the link between psoriasis and metabolic syndromes and advise them to maintain/adapt a healthy lifestyle.¹ Patients should be monitored by their primary care provider, including blood pressure, blood glucose, heart rate, weight, BMI and cholesterol, and referred to a cardiologist or other specialist if needed.¹

Obesity

Patients with psoriasis have a greater risk of obesity compared with those without psoriasis, with the highest risk seen in those with severe disease.³⁴ Being overweight or obese with psoriasis can have an impact on the efficacy of treatments (e.g., systemic therapies and biologics), making it harder to achieve a response,³⁵ with weight loss being shown to improve the efficacy of systemic and biologic therapies.^36,37 

Patients with moderate-to-severe psoriasis should have their body mass index determined each year.1 As mentioned earlier, patients with psoriasis should be encouraged to maintain a healthy lifestyle and weight.¹

Psychological disorders

Compared with the general population, patients with psoriasis are more likely to be depressed (up to 20%), suffer with anxiety and exhibit suicidal ideation extending to suicidal behaviour.^38,39 A systematic review and meta-analysis of 18 studies and a total of 330,207 patients with psoriasis reported that these patients, when compared with healthy individuals, were more likely to:⁴⁰ 

• Attempt suicide: OR, 1.32; 95% CI, 1.14–1.54 
• Complete suicide: OR, 1.20; 95% CI, 1.04–1.39 

It is important that dermatologists monitor for signs and symptoms of mental illness in their patients, particularly suicidal ideation.1 Anxiety and depression have been shown to improve with effective treatment of moderate-to-severe psoriasis, highlighting the need to optimise treatment regimens for patients.¹