Psoriasis is a chronic, non-infectious disease that affects mainlythe skin. It iscurrently suspected to be autoimmune in origin. It commonly causes red, scalypatches to appear on the skin, although some patients have no dermatologicalsymptoms. The scaly patches caused by psoriasis, called psoriatic plaques, are areas of inflammationand excessive skin production. Skin rapidly accumulates at these sites andtakes on a silvery-white appearance. Plaques frequently occur on the skin ofthe elbowsand knees, but canaffect any area including the scalp, palms of hands and soles of feet, and genitals.In contrast to eczema,psoriasis is more likely to be found on the extensor aspectof the joint.
The disorderis a chronic recurring condition that varies in severityfrom minor localized patches to complete body coverage. Fingernailsand toenails are frequently affected (psoriatic nail dystrophy) and can be seenas an isolated finding. Psoriasis can also cause inflammation of the joints,which is known as psoriatic arthritis. Ten to fifteen percent ofpeople with psoriasis have psoriatic arthritis.
The cause of psoriasis is not exact, but it is believed to have a geneticcomponent and it can be triggered by a prolonged injury to the skin.Factors that may aggravate psoriasis include stress,withdrawal of systemic corticosteroid, excessive alcohol consumption, and smoking.There are many treatments available, but because of its chronic recurrentnature psoriasis is a challenge to treat.
Quality of life
Psoriasis has been shown to affect health-related quality of life to anextent similar to the effects of other chronic diseases such as depression, myocardial infarction, hypertension,congestive heart failure or type2 diabetes. Depending on the severity and location of outbreaks,individuals may experience significant physical discomfort and some disability.Itching and pain can interfere with basic functions, such as self-care, walking, and sleep. Plaques on hands and feet can preventindividuals from working at certain occupations, playing some sports, and caringfor family members or a home. Plaques on the scalp can be particularlyembarrassing as flaky plaque in the hair can be mistaken for dandruff.Medical care can be costly and time-consuming and can interfere with anemployment or school schedule.
Individuals with psoriasis may also feel self-conscious about theirappearance and have a poor self-image that stems from fear of public rejectionand psychosexual concerns. Psychological distress can lead to significant depression and socialisolation.
In a 2008 National Psoriasis Foundation survey of 426 psoriasis sufferers,71 percent reported that the disease was a significant problem in everydaylife. More than half reported significant feelings of self-consciousness (63percent) and embarrassment (58 percent). More than one-third said they avoidedsocial activities and limited dating or intimate interactions.
Many tools exist to measure quality of life of patients with psoriasis andother dermatological disorders. Clinical research has indicated thatindividuals often experience a diminished quality of life. A 2009 study lookedat the impact of psoriasis by using interviews with dermatologists andexploring patient’s viewpoint. It found that in cases of mild and severepsoriasis, itch contributed most to the diminished health-related quality oflife
Psoriasis is usually graded as mild (affecting less than 3% of the body),moderate (affecting 3-10% of the body) or severe. Several scales exist formeasuring the severity of psoriasis. The degree of severity is generally basedon the following factors: the proportion of body surface area affected; diseaseactivity (degree of plaque redness, thickness and scaling); response toprevious therapies; and the impact of the disease on the person.
The Psoriasis Area Severity Index (PASI)is the most widely used measurement tool for psoriasis. PASI combines theassessment of the severity of lesions and the area affected into a single scorein the range 0 (no disease) to 72 (maximal disease). Nevertheless, the PASI canbe too unwieldy to use outside of trials, which has led to attempts to simplifythe index for clinical use.