Psoriasis Diagnosis

  • Diagnosis

    Psoriasis is a chronic disease in which scaling and inflammation occur on the outer layer of the skin Figure 01. Approximately 2% of the U.S. population has psoriasis. The condition is seen in all age groups but primarily affects adults. Men and women of all races are affected equally. An estimated 150, 000 new cases occur each year.

    Psoriais is categorized as mild, moderate, or severe. Approximately 70% to 80% of people with psoriasis have a mild form of the disease, while 20% to 25% have the moderate-to-severe type. The condition occurs in many forms, the most common of which is plaque psoriasis. Diagnosis can usually be made by the appearance of the lesion. Occasionally, psoriasis may mimic other skin conditions; in these cases a diagnosis is confirmed by a skin biopsy.

    Click to enlarge: Psoriasis

    Figure 01. Psoriasis

    Currently, there is no cure for psoriasis; however, proper treatment can control the disease. Treatments include over-the-counter products and prescription topical medications, shampoos, and ultraviolet (UV) light therapy. In more severe cases, oral medicine is available.

    The scaling and inflammation of psoriasis occur when cells in the outer layer of skin reproduce faster than usual and collect on the skin’s surface. Psoriasis results in patches of thick red or purple skin or plaque beneath silvery scales. In mild cases, the skin plaque covers a small area of the body. In more severe cases, the plaque is found in large areas all over the body.

    A malfunction in the immune system may predispose people to psoriasis. Although no one knows what causes psoriasis, scientists believe that an abnormality in the immune system may cause white blood cells that fight infection (T cells) to trigger inflammation and excessive skin growth. As a result, the inflamed skin sheds excessively every 3 to 4 days.

    Genetic factors predispose people to psoriasis. Psoriasis is more likely to occur in people with family members who have had psoriasis. In one third of the cases, scientists believe that psoriasis is inherited through a gene that causes the disease.

    Certain drugs, weather, and other conditions may cause psoriasis to become worse. Changes in climate, infection, stress, and dry skin may trigger a psoriasis flare-up. For example, winter weather causes the skin to become dry. In addition, sunlight, with its UV rays that are beneficial for psoriasis, is limited during these months. As a result, the condition may become more severe. Medications such as beta-blockers (used for high blood pressure), lithium (used for anxiety), and other medications may also cause a psoriasis outbreak.

    People with psoriasis typically have pain and itching as a result of skin plaque and inflammation Figure 01. Psoriasis appears as raised red or purple skin that is dry and covered by flaky, white scales. It usually itches and burns, and in some cases the skin may crack. Psoriasis is especially common on elbows, knees, and the scalp. It may occur in small patches, or in larger swaths. Flaking from psoriasis of the scalp may look like dandruff.

    You may be predisposed to the disorder if your family has a history of psoriasis, Psoriasis tends to run in families, which indicates that it may be a genetic disorder. Although no one really knows what causes psoriasis, scientists think that a defect in the immune system causes white blood cells (lymphocytes) to trigger skin cells to form rapidly and build up.

    Certain medications like beta blockers, lithium, and interferon can cause or aggravate psoriasis.

    New psoriasis plaques often occur after the skin is damaged (e.g., cut, scratched, rubbed, or severely sunburned).

    Before the physical examination, the doctor may ask whether you or your family have had psoriasis or immune disorders. The doctor may also ask if you have noticed changes in your skin that accompany changes in the weather, and will ask about any medications you are taking.

    When trying to diagnose psoriasis, the doctor will look for red skin that itches and burns, and is noticeably thicker than skin in other areas Table 01. Although psoriasis can affect any skin site, it is usually found on the elbows, knees, scalp, lower back, face, palms, and soles of the feet. Other common areas include the fingernails, toenails, and soft tissue of the mouth and genitals. Psoriasis has many forms. Each type differs in severity, duration, location, pattern, and appearance of the scales.

    Table 1.  Forms of Psoriasis

    Type Description
    Plaque Lesions consisting of thickened red skin coated with silvery scales.
    Guttate Tiny, drop-like lesions that occur on the trunk, limbs, and scalp. Usually triggered by a bacterial infection. Most common in children and young adults.
    Pustular Blisters of noninfectious pus on the skin as a result of medications, infections, emotional stress, or exposure to particular chemicals. Can affect large or small areas of the body.
    Inverse Large, dry, smooth, vividly red plaque in the folds of the skin near the genitals, under the breasts, or in the armpits. Caused by hypersensitivity to friction and sweating.
    Erythrodermic Widespread scaling and inflammation of the skin resulting from severe sunburn or use of oral steroids or other drugs. Produces itching and pain.

    If a physician suspects psoriasis, he or she may examine a small skin sample or biopsy to confirm the diagnosis. Because other conditions can resemble psoriasis, the physician may need to analyze a skin biopsy after carefully examining the skin, nails, and scalp.

    If you are diagnosed with psoriasis, the doctor will examine your skin to determine the severity of the disease Table 02.

    Table 2.  Forms of Psoriasis

    Lesions on less than 2% of body surfaceIsolated patches on the knees and elbows
    Lesions on 2% to 10% of body surfaceLesions on arms, legs, torso, and scalp
    Lesions or pustules cover more than 10% of body surfaceLesions on the hands or feet, legs, knees, arms, legs, torso, scalp, and fingernails

    If you have joint inflammation and pain in addition to psoriasis, you may have psoriatic arthritis. Approximately 7% to 30% of people with psoriasis have psoriatic arthritis. In some cases, the arthritis worsens as the skin condition worsens. Occasionally, improvement of the skin during therapy also results in improvement of the arthritis.

    Because no one knows what causes psoriasis, there are no methods of prevention. Psoriasis itself cannon be prevented; however, you may begin to notice events that trigger outbreaks, such as emotional stress, injury to the skin, some types of infection, and reaction to certain drugs.

  • Prevention and Screening

    Because no one knows what causes psoriasis, there are no methods of prevention. Psoriasis itself cannon be prevented; however, you may begin to notice events that trigger outbreaks, such as emotional stress, injury to the skin, some types of infection, and reaction to certain drugs.

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