Psoriasis usually begins in the liver, where the inflammation and flaking of the skin is due to an overreaction of the immune system. When this occurs, the body produces and sheds cells at a faster than normal speed. Experts believe that psoriasis can run in families with a history of the skin disorder; a cool, dry climate, infections or elevated stress can all trigger psoriasis flare-ups and create more patches. Medicine that is used to treat high blood pressure and non-steroidal anti-inflammatory drugs can also cause flare-ups.
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