Clinical Focus: Psoriasis: New Data on Comorbidities Associated with Psoriasis

Asignificant amount of research on psoriasis in recent years has focused on comorbidities and conditions associated with the disease. Psoriasis has been linked to heart disease, obesity, diabetes, and various other conditions in recent years, which has complicated how physicians have approached treatment. While the links between psoriasis and other disorders and diseases are well-documented, their origin is less known. Nevertheless, the growing data on comorbidities has highlighted a number of areas to which physicians should pay attention when they are deciding on therapeutic regimens.

New data on comorbidities was presented at the recent meeting of American Academy of Dermatology in Miami, FL. These data highlight significant trends in comorbidities and collectively represent the most up-to-date research on the topic. Posters that were presented covered a range of areas, including comorbidity risks over time, risks of cancer, and psoriasis and pregnancy. Following is an examination of this data.

Analyzing the Data
In one study (P 202), psoriasis patients were shown to be at slightly higher risk for CVD, depression, diabetes, and hypertension than the control group. The study evaluating 5,724 patients with new onset psoriasis also found increased risks for a variety of conditions during the first four years of having psoriasis, as compared to the control group. For example, patients in the first year of onset of psoriasis had an increase of 0.5 percent in their risk of obesity compared to the control group, while patients in their fourth year had a 1.4 percent increase in risk of obesity compared to the control group. Numbers for diabetes, depression, hypertension, and CVD were similar. These data indicate that longer duration of psoriasis is associated with more persistent comorbidities.

Psychiatric Disorders. New data has also shown that psoriasis is also associated with a higher frequency of psychiatric disorders (P 505). An average of three percent of psoriasis patients have been diagnosed with clinical depression, vs. 2.5 percent of the non-psoriatic population, and 1.8 percent of psoriasis patients have anxiety, as compared to 1.35 percent of the non-psoriatic population. The results showed that 8.2 percent of psoriasis patients use psychiatric medication, as opposed to 5.3 percent of the non-psoriatic population. In addition, children with psoriasis had a 25 percent greater risk of developing a psychiatric disorder than controls.

Psoriasis and Cancer. Another poster found that patients with psoriasis are at increased risk for cancer, as well (P3313). Based on an adjusted hazard ratio, the study found that psoriasis patients are 1.38 percent more likely to have malignant cancer, 1.72 percent more likely to have skin cancer, 1.82 percent more likely to have lymphoma, and 1.22 percent more likely to have prostate cancer. In addition to these data, a recent article found that patients with psoriatic disease are at in increased risk of pancreatic cancer, as well.¹

Psoriatic Arthritis. New results were also presented from the ADEPT trial, which examined patients with both psoriasis and psoriatic arthritis who achieved ACR 70 and still had persistent impairment (HAQ-DI scale 0-3). The study showed that onset of psoriatic arthritis in 90 percent of patients occurred at the time of psoriasis diagnosis or after. Evaluation revealed that the longer the patient had psoriasis prior to the diagnosis of psoriatic arthritis the more impairment the patient had from the arthritis. In fact, the HAQ scores increased 0.2 for every five years the patient had psoriasis prior to the diagnosis of psoriatic arthritis. This implies that subclinical psoriatic arthritis is occurring while the patient has psoriasis and gives reason to believe that effective treatment of psoriasis may decrease the impairment of psoriatic arthritis.

Pregnancy and Psoriasis. Another important study presented at the meeting was a retrospective analysis of the research registry within the Partners Healthcare System in Boston, MA. It examined prevalence and risk ratios of pregnancy outcomes in psoriasis patients. Results showed that patients with psoriasis were significantly more likely to have spontaneous abortions, preterm births, severe eclampsia, placenta previa, and ectopic pregnancy. Investigators concluded that there was an increase in poor pregnancy outcomes associated with psoriasis. The results remained significant after adjusting for race and obesity.

The Need to Monitor
These data affirm previous hypotheses and reveal new comorbidities related to psoriatic disease. As our awareness and knowledge about comorbidities grow, it is increasingly important to monitor all patients with severe psoriasis who may be at risk for a variety of associated conditions. This includes weighing all patients who appear to be overweight to determine if they are obese, evaluating lipid profiles and blood pressure, and performing hemoglobin A1C tests to determine if a patient has diabetes or metabolic syndrome. At the very least, patients should be consulting with their primary care physician if any potential risk is identified. It is also important to monitor a patient's mental health and talk to them about depression and anxiety.

Finally, given the significant findings of the pregnancy study cited above, dermatologists should facilitate discussions with female psoriasis patients of childbearing age and their obstetriciangynecologists about high risk pregnancy and steps that should be taken during pregnancy.

Dr. Bagel is on the speakers bureau for Abbott Labs, Genentech, Astellas, Amgen, and Stiefel.

1. Paul CF, Gourrad, PA. Cancer risk evaluation in psoriasis: in search of the Holy Grail? Journal of Investigative Dermatology. Nov;129(11):2547-9.
2. Poster abstracts accessible online at aad.org.