Researchers Tee Off on Psoriatic Arthritis

Psoriatic Arthritis associated with pro golfer Phil Mickelson

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Two recently published studies on Psoriatic Arthritis reveals new insights on environmental conditions that may affect the development of the autoimmune disease.

Psoriatic Arthritis, known as PsA, is a autoimmune condition more familiar with the public due to the 2010 announcement that pro golfer and Masters Champion Phil Mickelson is receiving treatment. 

PsA is a double whammy condition that occurs when a psoriasis patient develops a secondary autoimmune disease: rheumatoid arthritis. Skin and joints are simultaneously affected so that in even moderate cases it can be debilitating, disfiguring and painful.

According to the National Psoriasis Foundation approximately 30% of people who have psoriasis develop PsA.

"Ask your doctor about new arthritis treatments."

Two recent studies conducted by a Canadian research team investigated the effect of environmental factors that may contribute to developing PsA in psoriasis patients. The first study focused on determining if amounts of  vitamin D and seasonal sunlight exposure had any effect on PsA.  

As research has found in other studies of disease, levels of light and vitamin D can affect the body.  The second research study looked the possible effects of various environmental exposures and lifestyle choices for an association that may affect the development of PsA among those already with psoriasis. Findings were published online and printed in Arthritis Care and Research.

Dafna D. Gladman, Director of University of Toronto Psoriatic Arthritis Clinic in Canada was the lead author of both studies. Regarding the basis of the first study, Gladman said in a press release,  "It is more common to see individuals living in Northern regions with a deficiency in vitamin D than in those who reside in Southern areas."   

Because medical evidence has shown an association with deficient vitamin D levels in the blood with other autoimmune diseases, a total of 302 PsA patients were studied in Canada and Israel during winter and summer months. They were checked for vitamin D levels in the blood from sunlight synthesis and ingestion.  

The results of the study were that vitamin D insufficiency as opposed to a deficiency, predominated in the research groups in both locations and there was little variation of vitamin D in the blood levels from season to season. The conclusion was that PsA patients had vitamin D insufficiencies, but that the course of the disease was not affected by season, sunlight or location.  

What the researchers felt did need to be addressed and researched was the tendency for PsA patients to be lacking in vitamin D.

The second study released a month later by same group of authors looked at the environmental exposures of smoking, alcohol consumption, infections, injuries, physically demanding occupational tasks, stressful life events, vaccinations, and female hormonal differences among two groups of 159 patients, one group with PsA and another as a control.

The results of this study showed  that of these environmental exposures, heavy load lifting associated with an occupation contributed to the development of arthritis in psoriasis patients. Infections that required antibiotic treatments also had and association with psoriasis/PsA.

Smoking was found to have an inverse association with PsA . The remaining conditions were found by the researchers to have minimal to no effect on the occurrence of PsA in the trial subjects. In spite of these findings, researchers considered these results to be preliminary overall and  were unwilling to totally exclude the remaining environmental factors as inconsequential without additional research.

Published in Arthritis Care and Research.

Reviewed by: 
Review Date: 
September 14, 2011
Last Updated:
February 3, 2012