Psoriasis is a skin disease that causes itchy or sore patches of thick, red skin with silvery scales.
You usually get the patches on your elbows, knees, scalp, back, face, palms and feet, but they can show up on other parts of your body. Some people who have psoriasis also get a form of arthritis called psoriatic arthritis.
A problem with your immune system causes psoriasis. In a process called cell turnover, skin cells that grow deep in your skin rise to the surface. Normally, this takes a month. In psoriasis, it happens in just days because your cells rise too fast.
Psoriasis can be hard to diagnose because it can look like other skin diseases. Your doctor might need to look at a small skin sample under a microscope.
Psoriasis can last a long time, even a lifetime. Symptoms come and go.
Things that make them worse include
- Dry skin
- Certain medicines
Psoriasis usually occurs in adults. It sometimes runs in families. Treatments include creams, medicines, and light therapy.
Psoriasis is a skin disorder driven by the immune system, especially involving a type of white blood cell called a T cell. Normally, T cells help protect the body against infection and disease. In the case of psoriasis, T cells are put into action by mistake and become so active that they trigger other immune responses, which lead to inflammation and to rapid turnover of skin cells.
In many cases, there is a family history of psoriasis. Researchers have studied a large number of families affected by psoriasis and identified genes linked to the disease. Genes govern every bodily function and determine the inherited traits passed from parent to child.
People with psoriasis may notice that there are times when their skin worsens, called flares, then improves. Conditions that may cause flares include infections, stress, and changes in climate that dry the skin. Also, certain medicines, including beta-blockers, which are prescribed for high blood pressure, and lithium may trigger an outbreak or worsen the disease. Sometimes people who have psoriasis notice that lesions will appear where the skin has experienced trauma. The trauma could be from a cut, scratch, sunburn, or infection.
Psoriasis can appear suddenly or slowly. Many times, it goes away and then comes back.
The main symptom of the condition is irritated, red, flaky patches of skin. These patches appear most often on the elbows, knees, and middle of the body. But they can appear anywhere, including on the scalp.
The skin may be:
- Dry and covered with silver, flaky skin (scales)
- Pink-red in color (like the color of salmon)
- Raised and thick
Other symptoms may include:
- Genital sores in males
- Joint pain or aching
- Nail changes, including thick nails, yellow-brown nails, dents in the nail, and a lifting of the nail from the skin underneath
- Severe dandruff on the scalp
There are five main types of psoriasis:
- Erythrodermic -- The skin redness is very intense and covers a large area.
- Guttate -- Small, pink-red spots appear on the skin.
- Inverse -- Skin redness and irritation occur in the armpits, groin, and in between overlapping skin.
- Plaque -- Thick, red patches of skin are covered by flaky, silver-white scales. This is the most common type of psoriasis.
- Pustular -- White blisters are surrounded by red, irritated skin.
Occasionally, doctors may find it difficult to diagnose psoriasis, because it often looks like other skin diseases. It may be necessary to confirm a diagnosis by examining a small skin sample under a microscope.
There are several forms of psoriasis.
Some of these include:
- Plaque psoriasis. Skin lesions are red at the base and covered by silvery scales.
- Guttate psoriasis. Small, drop-shaped lesions appear on the trunk, limbs, and scalp. Guttate psoriasis is most often triggered by upper respiratory infections (for example, a sore throat caused by streptococcal bacteria).
- Pustular psoriasis. Blisters of noninfectious pus appear on the skin. Attacks of pustular psoriasis may be triggered by medications, infections, stress, or exposure to certain chemicals.
- Inverse psoriasis. Smooth, red patches occur in the folds of the skin near the genitals, under the breasts, or in the armpits. The symptoms may be worsened by friction and sweating.
- Erythrodermic psoriasis. Widespread reddening and scaling of the skin may be a reaction to severe sunburn or to taking corticosteroids (cortisone) or other medications. It can also be caused by a prolonged period of increased activity of psoriasis that is poorly controlled. Erythrodermic psoriasis can be very serious and requires immediate medical attention.
Another condition in which people may experience psoriasis is psoriatic arthritis. This is a form of arthritis that produces the joint inflammation common in arthritis and the lesions common in psoriasis. The joint inflammation and the skin lesions don’t necessarily have to occur at the same time.
Doctors generally treat psoriasis in steps based on the severity of the disease, size of the areas involved, type of psoriasis, where the psoriasis is located, and the patient’s response to initial treatments.
Treatments applied directly to the skin may improve its condition. Doctors find that some patients respond well to ointment or cream forms of corticosteroids, vitamin D3, retinoids, coal tar, or anthralin. Bath solutions and lubricants may be soothing, but they are seldom strong enough to improve the condition of the skin. Therefore, they usually are combined with stronger remedies.
- Topical corticosteroids. These drugs reduce inflammation and the turnover of skin cells, and they suppress the immune system. Corticosteroids are typically recommended for active outbreaks of psoriasis. Long-term use or overuse of highly potent (strong) corticosteroids can cause thinning of the skin, internal side effects, and resistance to the treatment’s benefits.
- Vitamin D analogs. Synthetic forms of vitamin D control the speed of turnover of skin cells. Excessive use of these creams may raise the amount of calcium in the body to unhealthy levels.
- Retinoids. Topical retinoids are synthetic forms of vitamin A.
- Coal tar. Preparations containing coal tar (gels and ointments) may be applied directly to the skin, added (as a liquid) to the bath, or used on the scalp as a shampoo. Coal tar products are available in different strengths, and many are sold over the counter (not requiring a prescription).
- Anthralin. Anthralin reduces the increase in skin cells and inflammation. Doctors may prescribe daily application of anthralin ointment, cream, or paste for brief periods to treat chronic psoriasis lesions. Afterward, anthralin must be washed off the skin to prevent irritation.
- Salicylic acid. This peeling agent, which is available in many forms such as ointments, creams, gels, and shampoos, can be applied to reduce scaling of the skin or scalp.
- Bath solutions. People with psoriasis may find that adding oil when bathing, then applying a lubricant, soothes their skin. Also, individuals can remove scales and reduce itching by soaking in water containing a coal tar solution, oiled oatmeal, Epsom salts, or Dead Sea salts.
- Lubricants. When applied regularly over a long period, lubricants have a soothing effect. Preparations that are thick and greasy usually work best because they seal water in the skin, reducing scaling and itching.
Natural ultraviolet (UV) light from the sun and controlled delivery of artificial UV light are used in treating psoriasis. It is important that light therapy be administered by a doctor. Spending time in the sun or a tanning bed can cause skin damage, increase the risk of skin cancer, and worsen symptoms.
- Sunlight. Much of sunlight is composed of bands of different wavelengths of UV light. When absorbed into the skin, UV light suppresses the process Fleading to disease, causing activated T cells in the skin to die. This process reduces inflammation and slows the turnover of skin cells that causes scaling.
- Ultraviolet B (UVB) phototherapy. UVB is light with a short wavelength that is absorbed in the skin’s epidermis. An artificial source can be used to treat mild and moderate psoriasis. A UVB phototherapy, called broadband UVB, can be used for a few small lesions, to treat widespread psoriasis, or for lesions that resist topical treatment. This type of phototherapy is normally given in a doctor’s office by using a light panel or light box. Some patients use UVB light boxes at home under a doctor’s guidance.
- Psoralen and ultraviolet A (UVA) phototherapy (PUVA). This treatment combines oral or topical administration of a medicine called psoralen with exposure to UVA light. UVA has a long wavelength that penetrates deeper into the skin than UVB. Psoralen makes the skin more sensitive to this light. Compared with broadband UVB treatment, PUVA treatment taken two to three times a week clears psoriasis more consistently and in fewer treatments. However, it is associated with more short-term side effects, including nausea, headache, fatigue, burning, and itching. Long-term treatment is associated with an increased risk of squamous-cell and, possibly, melanoma skin cancers.
For more severe forms of psoriasis, doctors sometimes prescribe medicines that are taken internally by pill or injection. This is called systemic treatment.
- Methotrexate. Like cyclosporine, methotrexate slows cell turnover by suppressing the immune system. It can be taken by pill or injection.
- Retinoids. Oral retinoids are compounds with vitamin A-like properties that may be prescribed for severe cases of psoriasis that do not respond to other therapies.
- Cyclosporine. Taken orally, cyclosporine acts by suppressing the immune system to slow the rapid turnover of skin cells. It may provide quick relief of symptoms, but the improvement stops when treatment is discontinued. Its rapid onset of action is helpful in avoiding hospitalization of patients whose psoriasis is rapidly progressing.
- Biologic response modifiers. Biologics are made from proteins produced by living cells instead of chemicals. They interfere with specific immune system processes which cause the overproduction of skin cells and inflammation. These drugs are injected (sometimes by the patient).
Combining various topical, light, and systemic treatments often permits lower doses of each and can result in increased effectiveness. There are many approaches for treating psoriasis. Ask the doctor about the best options for you.
- How long the treatment may last.
- How long it will take to see results.
- What the possible side effects are.
- What to do if the side effects are severe.
Psoriasis can be a life-long condition that can be controlled with treatment. It may go away for a long time and then return. Sometimes it goes away and never returns. With proper treatment it will not affect your overall health.