Psoriasis is a chronic inflammatory condition of the skin, which causes a red, scaly rash and affects about 125 million people worldwide. The cause of the disorder is probably multifactorial - involving heredity and the environment. While studies have linked psoriasis and higher weight, the causal relationship between the two has been unclear – such as what triggers it and what are the other underlying reasons for the connection? "Higher BMI may contribute to increased inflammation of the skin, which can exacerbate psoriasis, but it could also be that psoriasis leads to a person being less physically active and thus gaining weight," says Mari Løset, a medical doctor at the Department of Dermatology at St. Olavs Hospital and a postdoctoral fellow at the Norwegian University of Science and Technology's (NTNU) K.G. Jebsen Center for Genetic Epidemiology, as well as part of the team involved in a study of the causal relationship between BMI – body mass index - and psoriasis.
Two to four percent of the world’s population is affected by psoriasis – and it is particularly high in Norway. Data from two large population surveys in Norway indicate that six to 11 percent of the population may be affected. A study in the city of Tromsø shows that the incidence of psoriasis was 4.8 percent in 1980, but had increased to 11.4 percent in 2008 – and similar studies from other parts of the world substantiate the fact that the condition is increasing.
The researchers used a method called Mendelian randomization to investigate the causal relationship between BMI and psoriasis. Whether we inherit a certain variant of genes from our mother or our father is random, according to Mendel's principles of inheritance Genetic variants are randomly distributed, or randomized, between individuals. "Mendelian randomization means that nature itself distributes individuals randomly into groups based on genes,” Løset continued. “This way, we can avoid the results being influenced by external factors. Our understanding of how genes are related to disease is increasing at record speed, and in this study we used known genetic variants as markers for BMI and psoriasis."
The researchers found that higher weight is a contributing factor to psoriasis and that greater BMI increased the chance of getting the disease, but are still uncertain about just how higher weight can lead to psoriasis. "We calculated that the risk increased by nine percent for each higher whole number on the BMI scale," Løset said. "We still don't know enough about the mechanisms behind this connection. Fatty tissue is an organ that produces hormones and inflammatory signaling molecules, which could be a contributing factor."
While not much research has been done on whether weight loss can cause psoriasis to disappear, a few clinical studies suggest the possibility. "Psoriasis is a very complex disease and we hope to study subgroups, especially individuals with severe psoriasis,” Løset added. “The hypothesis is that we will be able to observe even greater links with higher weight."
Two New Psoriasis Guidelines
Psoriasis is associated with several other physical and mental conditions, and it can have a significant impact on patients’ quality of life. To help physicians treat the millions of people affected by psoriasis and improve their quality of life, the American Academy of Dermatology and the National Psoriasis Foundation have released two new guidelines outlining best practices for managing the inflammatory skin disease. The guidelines - published in the Journal of the American Academy of Dermatology were developed by an expert work group composed of several dermatologists, as well as a cardiologist, a rheumatologist and patient representatives. “It is critical for both patients and doctors to understand the complexity of psoriasis,” says Randy Beranek, president and CEO of the NPF. “It is not just a skin disease; it is a serious condition that can affect all aspects of a patient’s health. Our goal in establishing these guidelines is to help health care professionals educate their patients on the best way to treat their disease and mitigate the effects psoriasis can have on a patient’s overall health and well-being.”
The guidelines – called Joint AAD-NPF Guidelines Of Care For The Management And Treatment Of Psoriasis With Awareness And Attention To Comorbities - focus on the other health conditions that may be associated with the disease, including psoriatic arthritis, cardiovascular disease, metabolic syndrome and inflammatory bowel disease. The guidelines also address the increased risk of anxiety and depression in psoriasis patients, as well as the effects of smoking and alcohol consumption, which can increase one’s risk of developing the disease or make the condition worse in those who already have it. “We believe this guideline will be a vital resource in the treatment of psoriasis,” says Craig A. Elmets, MD, FAAD, board-certified dermatologist and co-chair of the work group that developed the guidelines. “Doctors should be aware of the conditions associated with this disease, educate patients accordingly, and work with those patients and other physicians to ensure that each patient receives the appropriate screening and treatment.”
The guidelines also provide an overview of the biologic medications available for the treatment of moderate to severe psoriasis. In addition to outlining the research on these drugs’ effectiveness and recommendations for their use, it describes the potential adverse effects of each biologic. “Before starting any psoriasis treatment, it’s important for patients to understand its potential effects, both positive and negative,” adds Alan Menter, MD, FAAD, also a board-certified dermatologist and co-chair of the guidelines work group. “This guideline provides physicians with the information they need to discuss biologic medications with their patients and help them choose the treatment plan that’s best for them.”
Treating Psoriasis Online
For approximately eight million Americans, visiting a doctor regularly is the key to managing their psoriasis, but for some, seeing a specialist regularly can be a challenge - especially for those who live in rural or underserved communities. A study - led by the Keck School of Medicine of USC - considers the possibility that one day people with psoriasis may be able to go online to receive their care. The study – published in JAMA Network Open - found that online and in-person care were equally effective at improving psoriasis symptoms. “Patients with chronic skin diseases need ongoing care, and depending on where they live, their access to dermatological care can be variable,” says April Armstrong, MD, MPH, professor of dermatology, associate dean for clinical research at the Keck School and the study’s lead author. “Our study suggests that an online care delivery model is an effective way to bring high-quality care to patients regardless of where they live or what their work/life schedules look like.”
The researchers followed nearly 300 patients who had been randomized to either online or in-person care and monitored their symptom improvement. Patients assigned to online care logged in to a secure, web-based connected health platform where they could communicate with their primary care provider or dermatologist, share images of their skin and receive treatment recommendations. After reviewing transmitted information, health care providers evaluated patients’ progress, provided patient education and prescribed medications electronically. Patients assigned to in-person care received treatment as usual.
Psoriasis severity was measured at baseline and again at three, six, nine and 12 months. Across the follow-up visits, the two groups achieved similar improvement in psoriasis severity scores. “From a patient’s perspective, there are several benefits to an online care delivery model: They don’t need to travel to a facility with specialty care, they can receive high-quality specialty care at home, and they can communicate with their doctor at a time that’s convenient for them,” Armstrong continued. “From a provider’s perspective, the benefits include flexibility in where and when they work.”
While this study focused on patients with psoriasis, Armstrong believes that the online care model has other potential applications as well. “The use of teledermatology needs to be considered in other patient populations with chronic skin diseases such as atopic dermatitis,” she added. “There is a critical need for children and adults with atopic dermatitis to receive high-quality specialist care for this condition through novel telehealth delivery methods.”
Can You Prevent Psoriasis With Vanilla Extract?
Small amounts of artificial vanilla extract - also known as vanillin - are found in a wide range of products from baked goods to perfumes but vanillin's versatility doesn't stop there. In a recent mouse study reported in ACS' Journal of Agricultural and Food Chemistry, researchers report that this compound could also prevent or reduce psoriatic skin inflammation. The cause of the disorder is probably multifactorial, involving both heredity and the environment. Immune system proteins called interleukins (IL) 17 and 23 are known to be key players in the development of the condition.
Vanillin can have effects on different interleukins that are involved in other inflammatory conditions and diseases. Researchers Chien-Yun Hsiang and Tin-Yun Ho decided to see if treatment with vanillin could prevent psoriatic symptoms. They induced psoriatic skin inflammation on groups of mice by putting a compound called imiquimod on their skin. The mice were orally given daily doses - 0, 1, 5, 10, 50 or 100 milligrams/kilograms of body weight - of vanillin for seven days. Mice treated with 50- or 100-milligram/kilograms of body weight doses had reduced psoriatic symptoms compared to those receiving smaller or no doses of vanillin. In all mice treated with vanillin, IL-17 and IL-23 protein levels were decreased. The researchers added that vanillin was an effective compound against psoriatic skin inflammation in this animal model.