To describe the natural history of a condition or disease. To describe the natural history of a condition or disease. To determine effectiveness or cost effectiveness of treatments/services and/or health care products. To measure or monitor safety and harm. To measure quality of care.
According to the NMSS, attacks or flare-ups of symptoms only qualify as exacerbations if: 1  they occur at least 30 days from an earlier flare-up. 2  symptoms last for 24 hours or longer.
The area may feel itchy and may have a burning sensation. You also never know how long it will last; it may last two days, two months or two years. The worst part for those afflicted by psoriasis is that the condition is persistent and will likely last a lifetime. This means flare-ups can occur anytime.