This special issue is dedicated to resident education on psoriasis. With that in mind, we hope to address many topics of interest to those in training. Over the years, diet has been a hot topic among psoriasis patients. They want to know how diet affects psoriasis and what changes can be made to their diet to improve their condition. Although they have expected specific answers, my response has usually been that they should, of course, eat an overall healthy and balanced diet, and lose weight if necessary. I have continued, however, that no specific diet has been recommended. However, now we have some information that may start to give us some answers.
The Mediterranean diet has been regarded as a healthy regimen.1 This diet emphasizes eating primarily plant-based foods, such as fruits and vegetables; whole grains; legumes; and nuts. Other recommendations include replacing butter with healthy fats such as olive oil and canola oil, using herbs and spices instead of salt to flavor foods, and limiting red meat to no more than a few times a month.1
As we know, psoriasis is a chronic inflammatory disease. The Mediterranean diet has been shown to reduce chronic inflammation and has a positive effect on the risk for metabolic syndrome and cardiovascular events.1 Phan et al1 hypothesized a positive effect of the Mediterranean diet on psoriasis. They performed a study to assess the association between a score that reflects the adhesion to a Mediterranean diet (MEDI-LITE) and the onset and/or severity of psoriasis.1
The NutriNet-Santé program is an ongoing, observational, web-based questionnaire cohort study launched in France in May 2009.1 Data were collected and analyzed between April 2017 and June 2017. Individuals with psoriasis were identified utilizing a validated online questionnaire and then categorized by disease severity into 1 of 3 groups: severe psoriasis, nonsevere psoriasis, and psoriasis free.1
During the initial 2 years of participation in the cohort, data on dietary intake (including alcohol) were gathered to calculate the MEDI-LITE score, ranging from 0 (no adherence) to 18 (maximum adherence).1 Of the 158,361 total web-based participants, 35,735 (23%) replied to the psoriasis questionnaire.1 Of the respondents, 3557 (10%) individuals reported having psoriasis. The condition was severe in 878 cases (24.7%), and 299 (8.4%) incident cases were recorded (cases occurring >2 years after participant inclusion in the cohort). After adjustment for confounding factors, the investigators found a significant inverse relationship between the MEDI-LITE score and having severe psoriasis (odds ratio [OR], 0.71; 95% CI, 0.55-0.92 for the MEDI-LITE score’s second tertile [score of 8 to 9]; and OR, 0.78; 95% CI, 0.59-1.01 for the third tertile [score of 10 to 18]).1
The authors noted that patients with severe psoriasis displayed low levels of adherence to the Mediterranean diet.1 They commented that this finding supports the hypothesis that the Mediterranean diet may slow the progression of psoriasis. If these findings are confirmed, adherence to a Mediterranean diet should be integrated into the routine management of moderate to severe psoriasis.1 These findings are by no means definitive, but it is a first step in helping us define more specific dietary recommendations for psoriasis.
This issue includes several articles looking at various facets of psoriasis important to residents, including the pathophysiology of psoriasis,2 treatment approach using biologic therapies,3 risk factors and triggers for psoriasis,4 and the psychosocial impact of psoriasis.5 We hope that you find this issue enjoyable and informative.