EXPERT ANALYSIS FROM THE EADV CONGRESS
VIENNA (FRONTLINE MEDICAL NEWS) – Recognition that psoriasis is a systemic inflammatory disease has recently spurred researchers to comb large databases for evidence of previously unidentified associations between the dermatologic disease and a variety of comorbid conditions. And the yield has been impressive.
Just within the past year, published studies have linked psoriasis to significantly increased risks of chronic obstructive pulmonary disease (COPD), multiple sclerosis (MS), migraine, uveitis, chronic pancreatitis, and abdominal aortic aneurysm, Matthias Augustin, MD, observed at a joint program of the International Eczema Council and the International Psoriasis Council held in conjunction with the annual congress of the European Academy of Dermatology and Venereology.
While he suspects the findings “are mostly true,” Dr. Augustin urged physicians and patients to interpret the heretofore unreported associations with caution.
“No patient-level validation studies have been done yet on the large databases used for this psoriasis research,” according to Dr. Augustin, professor of dermatology at the University of Hamburg-Eppendorf (Germany) and director of the Institute for Health Services Research in Dermatology and Nursing Professions at the university.
A critical reader of the recent studies will ask how the various investigators defined psoriasis severity, he continued. Some studies based that classification upon the type of treatment received. The trouble with that approach is if patients were undertreated, they will be misclassified. And as Mark G. Lebwohl, MD, and coinvestigators reported in the large, population-based Multinational Assessment of Psoriasis and Psoriatic Arthritis Survey, more than 80% of patients with moderate or severe psoriasis in North America and Europe receive no treatment or topical treatment only ( J Am Acad Dermatol. 2014; May;70:871-81 ).
Dr. Augustin stressed that his reservations about the recently reported novel comorbidities don’t apply to the psoriasis comorbidities first described years ago: namely, cardiovascular disease, depression, and elements of the metabolic syndrome. Those associations are by now well established, strong, and beyond question, although the issue of causality remains unresolved. Also, while numerous studies have confirmed the validity of these associations, there has been very little research to date exploring the effects of screening psoriasis patients for these comorbidities. This deserves to be a high-priority research area. It’s what health care policy makers and planners want to see before bumping psoriasis higher up on the list of high-impact diseases, according to the dermatologist.
Here is the back story on the recently reported novel comorbid conditions:
COPD. Investigators in Shanghai and Boston performed a systematic review and meta-analysis that yielded four observational studies totaling 13,418 subjects. Patients with mild to moderate psoriasis were found to be at 1.9-fold greater risk of developing COPD than the general population, while those with severe psoriasis were at 2.15-fold increased risk. This is a disturbing finding in light of psoriasis patients’ relatively high prevalence of smoking, further boosting their COPD risk ( PLoS One. 2015 Dec 23;10(12):e0145221. doi: 10.1371/journal.pone.0145221 ).
Multiple sclerosis. A Danish nationwide cohort study identified 58,628 adults with mild psoriasis, 9,952 with severe psoriasis, and 9,713 with multiple sclerosis. Utilizing the country’s comprehensive interconnected national system of birth to death registries, investigators at the University of Copenhagen determined that the incidence rate of multiple sclerosis was 1.78 cases per 10,000 person-years in the general population, 3.22 per 10,000 in patients with mild psoriasis, and 4.55 per 10,000 in those with severe psoriasis.
In a multivariate analysis adjusted for potential confounders, the adjusted incidence rate ratio of multiple sclerosis was 1.84-fold greater in patients with mild psoriasis and 2.61-fold greater in those with severe psoriasis than in the general population. The investigators concluded that psoriasis may confer a disease severity–dependent risk of MS ( J Invest Dermatol. 2016 Jan;136:93-8 ).
Migraine. In a study of all 5.4 million Danish adults, the risk of migraine after adjustment for numerous potential confounders was increased 1.37-fold in patients with mild psoriasis, 1.55-fold with severe psoriasis, and 1.92-fold in those with psoriatic arthritis, compared with the general population. The Danish investigators plan to look next at two key questions: Does effective psoriasis treatment reduce the risk of migraine? And does comorbid migraine modify psoriasis patients’ increased risk of cardiovascular disease? ( J Am Acad Dermatol. 2015 Nov;73:829-35 ).
Chronic pancreatitis. Taiwanese investigators turned to the country’s national health insurance research database for a population-based cohort study that included 48,430 psoriasis patients and 193,720 controls without psoriasis. During a mean 6.6 years of follow-up, the incidence of chronic pancreatitis was 0.61 cases per 1,000 person-years in the psoriasis patients, compared with 0.34 per 1,000 in controls.
After adjusting for age, gender, medications, and comorbid conditions, psoriasis patients remained at 76% increased risk of developing chronic pancreatitis. The risk was greater in patients with severe psoriasis than in those with mild disease. However, psoriasis patients on methotrexate were at an adjusted 72% lower risk of chronic pancreatitis than controls, suggesting that effective therapy for the dermatologic disease offers protection (PLoS One. 2016 Jul 28;11:e0160041. doi: 10.1371/journal.pone.0160041 ).
Uveitis. Reasoning that psoriasis, psoriatic arthritis, and uveitis are inflammatory disorders sharing some inflammatory pathways, Danish investigators conducted a nationwide cohort study that included 75,129 psoriasis or psoriatic arthritis patients and more than 13,000 patients with uveitis. They found a bidirectional relationship between psoriatic disease and uveitis. The incidence rate ratio for uveitis was 1.38-fold greater in patients with mild psoriasis than in the general population, 1.4-fold greater in patients with severe psoriasis, and 2.5-fold greater in those with psoriatic arthritis.
Moreover, patients with uveitis were 1.59-fold more likely to have mild psoriasis than controls from the general population, 2.17-fold more likely to have severe psoriasis, and 3.77-fold more likely to have psoriatic arthritis.
The investigators urged physicians to inquire about eye symptoms in their psoriasis and psoriatic arthritis patients and likewise to be attentive to skin and joint symptoms in patients with current or prior uveitis ( JAMA Dermatol. 2015 Nov;151:1200-5 ).
Abdominal aortic aneurysm. Once again, the University of Copenhagen dermatologic epidemiology group – “They are really productive at this time,” Dr. Augustin observed – carried out a nationwide cohort study and determined that the incidence of abdominal aortic aneurysm was 7.3 cases per 10,000 person-years in patients with mild psoriasis and 9.87 per 10,000 in those with severe psoriasis, compared with 3.72 per 10,000 in matched controls. The mechanisms involved in this relationship remain unclear, according to the investigators ( Arterioscler Thromb Vasc Biol. 2016 May;36:1043-8 ).
Dr. Augustin reported having no financial conflicts of interest regarding his presentation.