A new study has found that psoriasis can increase the risk of type 2 diabetes, and the more severe the psoriasis the higher the risk of diabetes.

The study, carried out at Perelman School of Medicine at the University of Pennsylvania and published in the June issue of the Archives of Dermatology, estimated that an additional 115,500 people will develop diabetes each year due to the risk posed by psoriasis above and beyond conventional risk factors.

The study compared 108,132 people with psoriasis to 430,716 matched patients without psoriasis. Those with mild psoriasis had an 11% increased risk of diabetes and those with severe psoriasis had a 46% higher risk compared to patients without psoriasis.

Both psoriasis and diabetes are diseases caused by chronic inflammation. A shared pathway -- TH-1 cytokines -- can promote insulin resistance and promote inflammatory cytokines known to drive psoriasis.

Diabetes can also cause ulceration of the skin, particularly in the lower leg region, which could either exacerbate existing psoriatic lesions or be more likely to occur to due to already existing psoriatic plaques.