A Closer Look At Non-Dermatologic Disorders Associated With Psoriasis

Psoriasis is one of the most common skin conditions, affecting 2 to 4 percent of the population.¹ Etiologies for this chronic, immune-mediated skin disease include both genetic and environmental factors. The five main types of psoriasis are plaque, guttate, inverse, pustular and erythrodermic. Nail changes (psoriatic onychodystrophy) are a common feature of psoriasis and include pitting, whitening, yellow-red oil drop or salmon spot discoloration, thickening, subungual hyperkeratosis and onycholysis. Nail changes occur in 40 to 45 percent of patients with psoriasis.² Psoriatic arthritis is a common, non-dermatological disorder associated with skin and nail psoriasis. Over 35 percent of patients with psoriasis have joint involvement.^3,4 Psoriatic arthritis is more common, occurs earlier and is more progressive in patients with psoriatic onychodystrophy.^2,5 Psoriatic arthritis is an inflammatory rheumatologic disorder that is included in the spondyloarthropathy group due to its clinical, radiographic and serologic features. Recently, researchers have identified several other non-dermatologic manifestations of psoriasis including metabolic syndrome, cardiovascular disease, insulin resistance, type 2 diabetes, lymphoma, anxiety and depression.^4,6-8 The hypothesis is that systemic inflammation associated with psoriasis contributes to the development of these extra-dermal manifestations. Kimball and colleagues reviewed data from a global, prospective, longitudinal, disease-based registry of patients with psoriasis.⁴ The authors found the following non-dermatologic manifestations: psoriatic arthritis in 35.5 percent of patients, cardiovascular disease in 38.2 percent of patients, type 2 diabetes in 11.4 percent of patients, depression in 14.7 percent of patients and anxiety in 11.1 percent of patients. The systemic inflammatory response associated with psoriasis is enhanced in patients with psoriatic arthritis. Peluso and coworkers found that 49 percent of patients with psoriatic arthritis patients had extra-articular manifestations.⁷ Systemic manifestations included bowel, ocular, cardiovascular, urogenital, skin (excluding psoriasis) and renal disorders. There was a higher incidence of extra-articular manifestation in patients with established psoriatic arthritis and the disease activity of psoriatic arthritis was higher in patients with extra-articular manifestations. Extra-articular manifestations are also more common in males, patients with a long disease duration and more active disease. Haroon and colleagues found a high prevalence of metabolic syndrome and insulin resistance in patients with psoriatic arthritis.⁸ Of a cohort of 283 patients with psoriatic arthritis, they found 44 percent to have metabolic syndrome and 16 percent of patients to have insulin resistance. There was a significant association of both metabolic syndrome and insulin resistance with more severe psoriatic arthritis. Given the recognition of psoriasis as a chronic systemic inflammatory condition, authors recommend long-term disease control with systemic maintenance therapy.⁶ A comprehensive management approach is recommended for psoriasis to address the dermatologic and non-dermatologic manifestations. It is important to recognize the non-dermatologic manifestations of psoriasis due to their severity and the frequency at which they occur. References 1. Parisi R, Symmons DP, Griffiths CE, Ashcroft DM. Global epidemiology of psoriasis: a systematic review of incidence and prevalence. J Invest Dermatol. 2013; 133(2):377–85. 2. Tan ES, Chong WS, Tey HL. Nail psoriasis: a review. Am J Clin Dermatol. 2012; 13(6):375–88. 3. Kivelevitch D, Mansouri B, Menter A. Long term efficacy and safety of etanercept in the treatment of psoriasis and psoriatic arthritis. Biologics. 2014; 8:169-82. 4. Kimball AB, Leonardi C, Stahle M, et al. Demography, baseline disease characteristics, and treatment history of patients with psoriasis enrolled in a multicenter, prospective, disease-based registry (PSOLAR). Br J Dermatol. 2014 Mar 28. [Epub ahead of print]. 5. Patrizi A, Venturi M, Scorzoni R, Pazzaglia M, Malavolta N, Bardazzi F. Nail dystrophies, scalp and intergluteal/perianal psoriatic lesions: risk factors for psoriatic arthritis in mild skin psoriasis? G Ital Dermatol Venereol. 2014;149(2):177-84. 6. Boehncke WH, Boehncke S. More than skin-deep: the many dimensions of the psoriatic disease. Swiss Med Wkly. 2014;144:w13968. 7. Peluso R, Iervolino S, Vitiello M, Bruner V, Lupoli G, Di Minno MN. Extra-articular manifestations in psoriatic arthritis patients. Clin Rheumatol. 2014 May 8. [Epub ahead of print]. 8. Haroon M, Gallagher P, Heffernan E, FitzGerald O. High prevalence of metabolic syndrome and of insulin resistance in psoriatic arthritis is associated with the severity of underlying disease. J Rheumatol. 2014;41(7):1357-65.