Psoriasis is a skin condition that causes red, flaky, crusty patches of skin covered with silvery scales. The condition is not infectious and most people are affected only in small patches on their body. The severity of psoriasis varies greatly from person to person. Psoriasis is a long-lasting disease (chronic) that can return at any time. There may be times when you have no symptoms or very mild symptoms followed by times when the symptoms are severe. Various supplements are useful for individuals who suffer from psoriasis.