Comorbidities in Psoriasis

Editor’s note: This is the final installment of an ongoing series on dermatological conditions and various associated comorbidities. The previous entries in the series can be found at PracticalDermatology.com/series/comorbidities/.

Psoriasis is an immune-mediated, systemic inflammatory disorder affecting up to 3% of the population in Western countries.¹ In psoriasis, keratinocytes exhibit abnormal proliferation and differentiation driven by both innate and adaptive immune responses, primarily through IL-17 expression induced by IL-23. This chronic, cytokine-mediated inflammation contributes to a broad range of comorbidities related to endothelial dysfunction and insulin resistance, including cardiovascular, metabolic, and neuropsychiatric disease.² Psoriatic arthritis and Crohn’s disease share overlapping genetic determinants with psoriatic disease, suggesting that their coexistence may differ from comorbidities secondary to chronic inflammation.² As therapeutic options for psoriasis continue to expand, understanding comorbidities has become essential to guide individualized, holistic care.

Diabetes Mellitus

Diabetes mellitus was one of the first comorbidities linked to psoriasis, with evidence suggesting the association is independent of traditional risk factors such as visceral adiposity.³ The risk of diabetic complications rises with increasing psoriasis severity,⁴ possibly mediated by IL-17–driven pathways.⁵ Treating both conditions optimally can be mutually beneficial. IL-17 inhibitors are effective for psoriasis in diabetic patients, and long-term metformin use has been shown to improve psoriasis severity.⁵

Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) including Crohn’s disease (CD) and ulcerative colitis (UC) is a well-recognized comorbidity of psoriasis. Both conditions share genetic susceptibility loci, such as MHC regions on chromosome 6p21 and non-MHC genes IL-23R and IL-12B.6 IL-23–driven IL-17 expression contributes to the pathogenesis of both diseases. While IL-17 promotes keratinocyte proliferation in psoriasis, its role in IBD is more complex: combined IL-17A and IL-17F blockade may improve colitis, but IL-17A inhibition alone can impair gut barrier function and worsen inflammation.^7,8 Patients with psoriasis have a 1.7- to 2.5-fold higher risk of CD and a 1.7-fold higher risk of UC.⁶

Metabolic Syndrome

Metabolic syndrome, characterized by insulin resistance, hypertension, dyslipidemia, and obesity, is increasingly common among psoriasis patients and correlates with disease severity.⁹ Reported prevalence ranges from 14.3% to 50%, with a higher likelihood among women.³ Consequently, cardiovascular disease (CVD) is more frequent, driven by both metabolic dysregulation and systemic inflammation. Psoriasis independently increases the risk of hypertension, dyslipidemia, myocardial infarction, diabetes, and ischemic stroke.³ Chronic kidney disease also occurs more frequently and may be independently associated.⁹ Metabolic-associated steatotic liver disease (MASLD) is more prevalent in psoriasis even after adjustment for body mass index, and hepatic injury is seen more often in patients with psoriasis or psoriatic arthritis on systemic therapy than in those treated for rheumatoid arthritis. Cytokine-mediated crosstalk between the liver and skin may underlie this link, underscoring the need for careful hepatic monitoring.⁹

Cancer 

A Danish meta-analysis found a modestly increased cancer risk in psoriasis, particularly keratinocyte carcinoma and lymphoma, though no excess risk was observed in patients treated with biologics.¹⁰ An Australian review reported similar findings, with slightly higher risks of lymphoma and certain solid organ malignancies—especially bladder and skin cancers, followed by malignancies of the oropharynx, larynx, liver, gallbladder, and colorectum—primarily in men and associated with tobacco and alcohol use.¹¹ Pediatric psoriasis was not linked to increased malignancy risk. Addressing modifiable lifestyle factors rather than avoiding immunomodulatory therapy may be more effective in reducing cancer risk.¹¹

Psychiatric Conditions

Psychiatric comorbidities are common and clinically significant. Anxiety and depression affect approximately 12% to 27% of patients,³ and psoriasis has long been recognized as a stress-exacerbated condition.¹² Individuals with psoriasis are 1.5 times more likely to develop depression,⁹ and those with major depressive disorder are at increased risk for psoriasis.³ Alcohol use disorder, somatoform disorder, schizophrenia, bipolar disorder, and personality disorders are also more prevalent.³ Effective psoriasis treatment can improve mental health outcomes, and addressing psychological well-being can, in turn, enhance dermatologic control.

Infectious Diseases

Infectious comorbidities are less common but clinically relevant. Although skin infections are not markedly increased, hepatitis C virus infections occur more frequently among psoriasis patients, likely reflecting shared cytokine-mediated mechanisms. HIV infection independently increases psoriasis risk, and herpes zoster is more common in patients receiving immunosuppressive therapy.³

Psoriatic Arthritis

Psoriatic arthritis (PsA) remains the most clinically impactful comorbidity, requiring prompt recognition and management. Up to one-third of psoriasis patients develop PsA, with risk correlating with disease severity.³ According to joint American Academy of Dermatology (AAD)–National Psoriasis Foundation (NPF) guidelines, 64.5% of patients develop cutaneous disease before arthritis, 16.1% present with both simultaneously, and 19.4% develop arthritis first.⁹ Psoriatic arthritis independently increases cardiovascular risk, likely reflecting higher systemic inflammation.² Regular screening, patient education, and early initiation of disease-modifying therapy are critical to preventing joint damage.

Nail Disease

Nail disease occurs in up to 50% of psoriasis patients and 80% of those with PsA, significantly impacting quality of life. Nail psoriasis can involve the matrix (pitting, leukonychia) or nail bed (onycholysis, subungual hyperkeratosis, oil spots). Approximately 10% of patients with nail psoriasis have PsA, reinforcing the need for musculoskeletal screening in patients with nail involvement.¹³

Pregnancy

Pregnancy can influence psoriasis unpredictably. About 40% of patients report improvement during pregnancy, 20% report worsening, and up to 50% experience flares postpartum.¹⁴ Pustular psoriasis of pregnancy (PPP; impetigo herpetiformis) is a rare but severe form of generalized pustular psoriasis that often worsens during gestation and resolves postpartum. PPP carries a high inflammatory burden and may adversely affect maternal and fetal outcomes.¹⁴ Careful treatment selection during pregnancy is therefore essential.

Other less common comorbidities include periodontitis, ocular disease (keratopathy, retinal disease, uveitis), and sensorineural hearing loss.³

In summary, psoriasis is a chronic, systemic inflammatory disease with a substantial inflammatory burden and a wide range of associated comorbidities. Recognition and proactive management of these conditions are key to optimizing psoriasis outcomes, improving overall health, and enhancing quality of life for patients. 

1. Tang X, Chen L. The risk of organ-based comorbidities in psoriasis: a systematic review and meta-analysis. An Bras Dermatol. 2022;97(5):612-623. https://doi.org/10.1016/j.abd.2022.01.001

2. Puig L. Cardiometabolic comorbidities in psoriasis and psoriatic arthritis. Int J Mol Sci. 2017;19(1):58. https://doi.org/10.3390/ijms19010058

3. Bu J, et al. Epidemiology of psoriasis and comorbid diseases: a narrative review. Front Immunol. 2022;13:880201. https://doi.org/10.3389/fimmu.2022.880201

4. Takeshita J, et al. Psoriasis and comorbid diseases: epidemiology. J Am Acad Dermatol. 2017;76(3):377-390. https://doi.org/10.1016/j.jaad.2016.07.064

5. Yamazaki F. Psoriasis: comorbidities. J Dermatol. 2021;48(6):732-740. https://doi.org/10.1111/1346-8138.15869

6. Fu Y, Lee CH, Chi CC. Association of psoriasis with inflammatory bowel disease: a systematic review and meta-analysis. JAMA Dermatol. 2018;154(12):1417-1423. https://doi.org/10.1001/jamadermatol.2018.3331

7. Ohara D, Takeuchi Y, Hirota K. Type 17 immunity: novel insights into intestinal homeostasis and autoimmune pathogenesis driven by gut-primed T cells. Cell Mol Immunol. 2024;21(11):1183-1200. https://doi.org/10.1038/s41423-024-01129-7

8. Zhang JX, et al. Risk of new-onset inflammatory bowel disease in psoriasis patients treated with five different interleukin inhibitors: a systematic review and meta-analysis. Front Immunol. 2025;16:1594998. https://doi.org/10.3389/fimmu.2025.1594998

9. Elmets CA, et al. Joint AAD-NPF guidelines of care for the management and treatment of psoriasis with awareness and attention to comorbidities. J Am Acad Dermatol. 2019;80(4):1073-1113. https://doi.org/10.1016/j.jaad.2018.11.057

10. Vaengebjerg S, et al. Prevalence, incidence, and risk of cancer in patients with psoriasis and psoriatic arthritis: a systematic review and meta-analysis. JAMA Dermatol. 2020;156(4):421-429. https://doi.org/10.1001/jamadermatol.2019.5636

11. Rademaker M, et al. Psoriasis and cancer: an Australian/New Zealand narrative. Australas J Dermatol. 2019;60(1):12-18. https://doi.org/10.1111/ajd.12874

12. Rosenø NAL, et al. Exploring disease comorbidities and temporal disease progression of psoriasis: an observational, retrospective, multi-database, cohort study. Br J Dermatol. 2023;188(3):372-379. https://doi.org/10.1093/bjd/ljad154

13. Hwang JK, et al. Nail psoriasis and nail lichen planus: updates on diagnosis and management. J Am Acad Dermatol. 2024;90(3):585-596. https://doi.org/10.1016/j.jaad.2023.08.047

14. Simionescu AA, Danciu BM, Stanescu AMA. State-of-the-art review of pregnancy-related psoriasis. Medicina (Kaunas). 2021;57(8):792. https://doi.org/10.3390/medicina57080792

NEDA GHIAM, MD, MS

PGY-4 Resident Physician at Larkin Palm Springs Dermatology Program 
Miami, FL 

AMIT SHARMA, DO

Board-certified dermatologist, Guthrie Medical Group 
Corning, NY 

BRAD P. GLICK, DO, MPH, FAAD

Dermatology Residency Program Director

Larkin Health System - Palm Springs Campus 
Miami, FL