Psoriasis: A Review

A look at the collaborative efforts that led to the development of the first public health agenda for psoriasis and psoriatic arthritis, along with a review of recent psoriasis research and news.

Public Health Agenda for Psoriasis and Psoriatic Arthritis

A public health agenda for psoriasis and psoriatic arthritis has been developed through collaboration between the Centers for Disease Control and Prevention (CDC) and the National Psoriasis Foundation (NPF). The new public health agenda for psoriasis and psoriatic arthritis was developed through a 2-phase process. In the first phase, which ran from April to September of 2010, meetings with psoriatic disease experts were held to identify and discuss key issues pertinent to developing a public health agenda. The second phase of the project, which began in September 2010, focused on refining the literature review of public health case definitions for psoriasis and psoriatic arthritis.

As a result of these 2 collaborative phases, 6 relevant public health issues were identified: (1) prevalence, (2) age of onset, (3) costs (direct and indirect), (4) healthcare utilization, (5) employment/work, and (6) health-related quality of life. From these 6 topics, the researchers put together a Public Health Agenda intended to guide population-based research in the United States and applies to psoriasis and psoriatic arthritis. The priorities, according to information from the NPF, include improving the way psoriasis and psoriatic arthritis are diagnosed, the relationship between other chronic diseases or comorbidities with psoriasis and psoriatic arthritis, identifying ways people with psoriatic diseases access care and manage the cost of treatments, and how the diseases affect patients’ ability to work.

Detecting Individual Risk Factors for Comorbidities in Patients with Psoriasis

A growing body of literature demonstrates a link between psoriasis and certain comorbidities, including heart disease, metabolic disorder, and inflammatory bowel disease. A study reported in Archives of Dermatological Research [2013;305(2):91-98], provides suggestions for detecting individual risk factors for comorbidities in patients with psoriasis. This study, conducted by a group of researchers from institutions in Germany, examined 3 broad categories of comorbidities that may occur in psoriasis patients: (1) cardiovascular risk, (2) metabolic syndrome, and (3) psychosocial stress and mental illness.

The authors identified 10 specific cardiovascular risk factors and concluded that 5 are of particular relevance: (1) age, (2) sex, (3) chronic nicotine abuse, (4) dyslipidemia, and (5) arterial hypertension. The group also examined 2 specific risk factors in the context of metabolic syndrome—(1) insulin resistance and (2) being overweight/obese—and concluded that both are relevant as individual risk factors for metabolic syndrome in patients with psoriasis.

Finally, in their examination of psychosocial stress and mental illness, the researchers discussed the prevalence of diseases such as depression in psoriasis patients and the increased likelihood of patients with psoriasis being addicted to alcohol and other substances. According to the study results, these issues are most prominent in patients with severe disease and may affect as many as a quarter to a third of all psoriasis patients. The researchers concluded that all psoriasis patients be evaluated and monitored for signs of psychosocial stress and mental illness.

The researchers then developed a checklist of recommendations for detecting individual risk factors for comorbidities in psoriasis patients based on the investigation. The researchers believe the checklist “allows the dermatologist to detect systematically all relevant factors and facilitate the assessment regarding an interdisciplinary complementary treatment.”

In their conclusion, the authors write: “Although existing recommendations for the frequency of the reassessment of each parameter may differ and the time intervals suggested cannot yet be thoroughly evidence based, we recommend a yearly re-evaluation.”

Children with Psoriasis may be at Risk for the Same Comorbidities as Adults

The comorbidities that are well established in adult patients with psoriasis may also affect children with the skin disease, according to the results of a new study reported in the British Journal of Dermatology [2013;168(3):661-663]. The researchers, who report that one third of adult patients with psoriasis present initially in childhood, performed a literature search using the terms comorbidities, children, and psoriasis that resulted in 5 relevant papers.

The largest data set (3862 children) was drawn from German health insurance data. According to the study, “the larger cohort showed that 0.71% of those under the age of 18 years had an International Classification of Diseases, Tenth Revision diagnosis of psoriasis (2549/306,020 children) with the expected incremental curve of prevalence of childhood psoriasis increasing with age (from 0 to 18 years).”

Overall, children with psoriasis had a 2-fold increased risk of comorbidities associated with the skin disease, including hyperlipidemia, obesity, hypertension, diabetes mellitus, rheumatoid arthritis, and Crohn’s disease. Crohn’s disease was up to 4 times more common in patients with psoriasis, according to the researchers.

Ischemic heart disease and ulcerative colitis were also more prevalent in the group of children with psoriasis, but this was not statistically significant. In the second, smaller cohort, Kämpfe et al identified 1313 children with psoriasis of a cohort of 293,181, again finding increased rates of obesity, diabetes mellitus, depression, arthritis, and hypertension among children with the skin disease.

The smaller, secondary care cohorts (565 children) came from China and Italy and also demonstrated an increased risk of obesity in children with psoriasis. Zhu et al looked at 332 children with plaque psoriasis and found a significantly greater proportion of children with psoriasis who were overweight or obese compared with controls. Similar findings were reported by Boccardi et al, which compared 96 children with psoriasis to 100 controls and found a positive association between psoriasis and being overweight, particularly in boys and children <10 years of age.

A study of childhood psoriasis in China by Wu et al looked at 137 patients with childhood psoriasis between 3 and 14 years of age and demonstrated comorbidities, including allergic contact dermatitis, eczema, vitiligo, and alopecia areata. However, the authors noted, the data did not include a control group.

In the last study by Brauchli et al, the researchers reviewed data from the UK General Practice Research Database for evidence of increased rates of diabetes mellitus; as expected, the incidence rate ratio for diabetes mellitus was significantly greater in patients with psoriasis. According to the researchers, the study looked at all age ranges, so the numbers were not included in the review, but were grouped by those <30 years of age; this age group had the highest incidence rate ratio of all age groups analyzed.

Based on the limited data the researchers were able to analyze, they concluded that, “there may be evidence of comorbid disease, associated with metabolic syndrome, detected at an early age in young people with psoriasis.” While they acknowledged that more work is needed, they suggested their work provides the ability in the interim “to reinforce healthy lifestyle choices in children in general but particularly those with psoriasis.” They also wrote that the study raises a question about whether dermatologists should monitor children for associated features of metabolic syndrome.

Biologic Therapy in Psoriasis Patients with Concominant Hepatitis B or C

Due to concerns about efficacy and the impact of the therapy on liver disease, the use of biologic agents in patients with hepatitis has been debated. A new retrospective, multicenter study reported in the British Journal of Dermatology [2013;168(3):609-616] found that several anti-TNF-alpha (anti-TNF-α) biologic agents and one interleukin 12/23 agent are safe and efficacious in patients with concomitant hepatitis and psoriasis.

The team of researchers, from departments of dermatology in institutions in Spain, examined 20 psoriasis patients with hepatitis C and 5 psoriasis patients with hepatitis B. Patients with hepatitis C received either etanercept, adalimumab, ustekinumab, or infliximab; some were treated with >1 biologic agent. Patients with hepatitis B received etanercept, ustekinumab, or infliximab.

In patients with hepatitis C, the viral loads increased in 18% of patients for whom quantitative viral tests were obtained; in 1 patient with an alcohol habit, liver enzymes nearly doubled. Treatment with etanercept was discontinued in 2 patients due to hepatocellular carcinoma diagnoses following 9 and 12 months of treatment; one of these patients presented with cirrhosis at baseline and had a past alcohol habit.

The researchers noted that, to their knowledge, their study is the first to examine ustekinumab in patients with psoriasis and hepatitis; liver enzyme levels and viral loads did not increase in the ustekinumab-treated patients. In the 2009 European guidelines for the use of anti-TNF-α therapy in patients with psoriasis, active chronic hepatitis B is listed as “an absolute contraindication,” according to the researchers, but the current study revealed no negative reactions. Both anti-TNF-α agents (etanercept and infliximab) were well tolerated in this patient population, as was ustekinumab; viral loads and liver enzymes did not significantly increase in any patients and the researchers did not see any signs of acute hepatitis.

In both groups of patients—those with hepatitis C and those with hepatitis B—the biologic agents for psoriasis also proved to be effective in terms of psoriasis management. In the group of hepatitis C patients, 69% of the cases achieved a Psoriasis Area and Severity Index (PASI) score of 75 during the follow-up period; 13 of 26 cases maintained a PASI score of 75 until the end of the follow-up period. In the group of patients with hepatitis B, 100% of cases achieved at least a PASI score of 75 and 60% maintained it until the end of the follow-up period.

“We consider hepatitis B and C to be relative contraindications for the use of biologic agents in the treatment of psoriasis,” the researchers concluded. “Their use should be limited to those cases in which the risk:benefit ratio is justified, because of possible aggravation or reactivation of the hepatitis. When this is the case, we recommend close monitoring of the patients in association with the gastroenterology department by means of periodic laboratory tests, including liver function and viral load, and prophylactic treatment in all cases of HBV infection.” Forest University Dermatology 2009

Treatment Costs and Access to Care

A new analysis of data from the NPF shows the cost of treatment and access to care continue to significantly affect the lives of patients with psoriasis and psoriatic arthritis. A team of psoriasis researchers, led by April Armstrong, MD, MPH, of the University of California, Davis, analyzed 8 years of data from the NPF, looking specifically at access-to-care issues and out-of-pocket costs.

Of >5600 people with psoriasis and psoriatic arthritis who were analyzed, 92% said they had seen at least 1 physician in 2 years. Among individuals who sought care, 22% saw a primary care physician. When asked why they did not see a specialist—either a dermatologist or a rheumatologist—for treatment, patients said they had given up on treatment (28%), found treatment to be too expensive (21%), or found treatment to be too much of a hassle (11%).

The majority of patients with psoriasis and psoriatic arthritis (91%) had health insurance. However, the majority also had >$2500 per year in out-of-pocket costs related to psoriasis. Patients with access to insurance and those with severe psoriasis were more likely to see a specialist, NPF data show. Women were 1.5 times more likely to seek care than men.