Individuals with psoriasis experience symptoms such as itching, cracking, stinging, burning, or bleeding. Lack of sunlight and low indoor humidity in the winter months can cause the psoriasis symptoms to worsen. The affected skin may crack at the joints where the body bends, or in areas where the individual scratches. Scratching should be strictly avoided, because it can cause bleeding and infection. Psoriasis has also been known to cause pits or dents to form in fingernails and toenails. There is also the possibility that the soft tissue inside the mouth and genitalia can be affected.
New skin cells take about a month or so to move from the deepest skin layer where they're produced, to the surface where they die and flake off. With psoriasis, the entire skin cell life cycle takes only days leading to an accumulation on the skin surface causing irritation, itching and redness.
People with psoriasis may notice that there are times when their skin worsens, then improves. Conditions that may cause flareups include changes in climate, infections, stress, and dry skin. Also, certain medicines, most notably beta-blockers, which are used in the treatment of high blood pressure, and lithium or drugs used in the treatment of depression, may cause an outbreak or worsening of the disease.
