Plaque psoriasis is the most common type of psoriasis and is characterized by red skin covered with silvery scales and inflammation.Patches of circular to oval shaped red plaques that itch or burn are typical of plaque psoriasis.Unpredictable and irritating, psoriasis is one of the most baffling and persistent of skin disorders. It's characterized by skin cells that multiply up to 10 times faster than normal. As underlying cells reach the skin's surface and die, their sheer volume causes raised, red plaques covered with white scale.The patches are usually found on the arms, legs, trunk, or scalp but may be found on any part of the skin. The most typical areas are the knees and elbows.
Approximately 1-2% of people in the United States, or about 5.5 million, have plaque psoriasis.
People who suffer from psoriasis know that this uncomfortable and at times disfiguring skin disease can be difficult and frustrating to treat. The condition comes and goes in cycles of remissions and flare-ups over a lifetime. While there are medications and other therapies that can help to clear up the patches of red, scaly, thickened skin that are the hallmark of psoriasis, there is no cure.
A variety of factors -- ranging from emotional stress and trauma to dry skin and streptococcal infection -- can cause an episode of psoriasis. Recent research indicates that some abnormality in the immune system is the key cause of psoriasis.
Research indicates that the disease may result from a disorder in the immune system.The immune system makes white blood cells that protect the body from infection.In psoriasis, the T cells (a type of white blood cell) abnormally trigger inflammation in the skin.These T cells also cause skin cells to grow faster than normal and to pile up in raised patches on the outer surface of the skin.
Overactive T cells trigger other immune responses including dilation of blood vessels in the skin around the plaques and an increase in other white blood cells that can enter the epidermis. These changes result in an increased production of both healthy skin cells and more T cells and other white blood cells. What results is an ongoing cycle in which new skin cells move to the outermost layer of skin too quickly - in days rather than weeks. Dead skin and white blood cells can't slough off quickly enough and build up in thick, scaly patches on the skin's surface. This usually doesn't stop unless treatment interrupts the cycle.
Just what causes T cells to malfunction in people with psoriasis isn't entirely clear, although researchers think genetic and environmental factors both play a role.
Certain factors may trigger psoriasis.
Injury to the skin: Injury to the skin has been associated with plaque psoriasis.For example, a skin infection, skin inflammation, or even excessive scratching can trigger psoriasis.
Sunlight: Most people generally consider sunlight to be beneficial for their psoriasis. However, a small minority find that strong sunlight aggravates their symptoms. A bad sunburn may worsen psoriasis.
Streptococcal infections:Some evidence suggests that streptococcal infections may cause a type of plaque psoriasis.These bacterial infections have been shown to cause guttate psoriasis, a type of psoriasis that looks like small red drops on the skin.
As many as 80% of people having flare-ups report a recent emotional trauma, such as a new job or the death of a loved one. Many doctors believe such external stressors serve as triggers for an inherited defect in immune function.
HIV: Psoriasis typically worsens after an individual has been infected with HIV. However, psoriasis often becomes less active in advanced HIV infection.
Drugs: A number of medications have been shown to aggravate psoriasis. Some examples are as follows:
- Lithium - Drug that may be used to treat depression
- Beta-blockers - Drugs that may be used to treat high blood pressure
- Antimalarials - Drugs used to treat malaria
- NSAIDs - Drugs, such as ibuprofen (Motrin and Advil) or naproxen (Aleve), used to reduce inflammation
Also contributing factors:
- Emotional stress: Many people see an increase in their psoriasis when emotional stress is increased.
- Smoking: Cigarette smokers have an increased risk of chronic plaque psoriasis.
- Alcohol: Alcohol is considered a risk factor for psoriasis, particularly in young to middle-aged males.
Hormone changes: The severity of psoriasis may fluctuate with hormonal changes. Disease frequency peaks during puberty and menopause. A pregnant woman's symptoms are more likely to improve than worsen, if any changes occur at all. In contrast, symptoms are more likely to flare in the postpartum period, if any changes occur at all.
An individual with plaque psoriasis usually has patches of red, raised, scaly areas on the skin that may itch or burn.The patches are usually found on the knees, elbows, trunk, or scalp. Approximately, 9 out of 10 people with psoriasis have plaque psoriasis.
Symptoms for each type may vary in severity and appear in a wide array of combinations. In general, the major symptoms of psoriasis include:
- Bright red areas of raised patches (plaques) on the skin, often covered with loose, silvery scales. Plaques can occur anywhere, but commonly they occur on the knees, elbows, scalp, hands, feet, or lower back. Nearly 90% of people with psoriasis have plaque-type psoriasis.
- Tiny areas of bleeding when skin scales are picked or scraped off (Auspitz's sign).
- Mild scaling to thick, crusted plaques on the scalp.
- Itching, especially during sudden flare-ups or when the psoriasis patches are in body folds, such as under the breasts or buttocks.
- Nail disorders. Nail disorders are common, especially in severe psoriasis. Nail symptoms include:
- Tiny pits in the nails (not found with fungal nail infections).
- Yellowish discoloration of the toenails and sometimes the fingernails.
- Separation of the end of the nail from the nail bed.
- Less often, a buildup of skin debris under the nails.
- Similar plaques in the same area on both sides of the body (for example, both knees or both elbows).
- Flare-ups of many raindrop-shaped patches. Called guttate psoriasis, this condition often follows a strep infection and is the second most common type of psoriasis. It affects less than 10% of those with psoriasis.1
- Joint swelling, tenderness, and pain (psoriatic arthritis).
Psoriasis treatments aim to:
Interrupt the cycle that causes an increased production of skin cells, thereby reducing inflammation and plaque formation.
Remove scale and smooth the skin, which is particularly true of topical treatments that you apply to your skin.
Psoriasis treatments can be divided into three main types: topical treatments, light therapy and oral medications.
Medicines applied to the skin (topical treatments)
Treatment for mild psoriasis, characterized by a few isolated raised patches, begins with skin care, which includes keeping your skin moist. Basic treatment often involves combining treatments and products that you can get without a prescription, including:
- Creams, ointments, and lotions to moisturize the skin.
- Shampoos, oils, and sprays to treat psoriasis of the scalp.
- Some exposure to sunlight.
It is also important to avoid what can trigger a flare-up of psoriasis or make the condition worse. Stress, skin injury, infection, and use of alcohol can all contribute to symptom flare-ups. Streptococcal infections, which usually affect the upper respiratory tract, are associated with guttate psoriasis.
Effective treatment will improve your overall well-being and reduce your physical symptoms.
You may try prescription medicines if your psoriasis is not helped by products you can get without a prescription. Topical medicines for psoriasis treatment include:
- Vitamin D compounds, such as calcipotriene.
- Topical corticosteroids, such as betamethasone.
- Anthralin and tars.
- Retinoids, such as tazarotene.
In addition, these tips can help:
- Exposure to sunlight helps many people with psoriasis.
- Keeping the skin soft and moist is helpful.Apply heavy moisturizers after bathing.
- Do not use irritating cosmetics or soaps.
- Avoid scratching or itching that can cause bleeding or excessive irritation.
- Soaking in bath water with oil added and using moisturizers may help.Bath soaks with coal tar or other agents that remove scales and reduce the plaque may also help.
- Cortisone creams can reduce the itching of mild psoriasis and are available without a prescription.
Some people use anultraviolet B unit at home under a doctor's supervision.A dermatologist may prescribe the unit and instruct the patient on home use, especially if it is difficult for the patient to get to the doctor's office for phototherapy treatment.