Psoriasis is a persistent, inflammatory skin condition. Some cases of psoriasis are so mild that people don’t know they have it. Alternatively, severe psoriasis may cover large areas of the body. Dermatologists can help even the most severe cases. Psoriasis is not contagious, so it cannot be passed from one person to another. Psoriasis does, however, have a tendency to run in families, meaning it can be an inherited condition.
Causes Of Psoriasis
While the cause is unknown, research indicates that the immune system plays a key role. It is believed that the person’s immune system mistakenly activates T cells, a type of white blood cell. Once activated, the T cells trigger inflammation, which causes the skin to grow too rapidly. Normally, the skin replaces itself about every 30 days. When the process speeds up and the skin replaces itself in three to four days, psoriasis develops.
A “trigger” is usually needed to make psoriasis appear, whether for the first time or the twentieth. Psoriasis can be triggered by stress; an infection, such as strep throat; and by taking certain medicines, such as interferon and lithium. Cold, dry winter weather and lack of sunlight also can trigger psoriasis. Others see psoriasis flare 10 to 14 days after their skin is injured, such as by a cut, scratch, or severe sunburn. This is known as Koebner’s phenomenon.
Types Of Psoriasis
There are five major types of psoriasis, each with unique signs and symptoms:
- PLAQUE PSORIASIS The most common type, plaque psoriasis appears as patches of raised, reddish skin covered by silvery-white scale. Patches frequently form on the elbows, knees, lower back, and scalp, but can occur anywhere on the skin.
- GUTTATE PSORIASIS Appearing as small, red spots, guttate psoriasis usually affects children and young adults. It often starts after a sore throat, and frequently clears up by itself in weeks or a few months.
- PUSTULAR PSORIASIS Characterized by white pustules surrounded by red skin, pustular psoriasis tends to confine itself to certain areas of the body, usually the palms and sales. Dermatologists call this “localized pustular psoriasis. ” When widespread, the condition is known as “generalized pustular psoriasis,” which is a rare and severe form of psoriasis that can be life threatening.
- INVERSE PSORIASIS This type occurs when smooth, red lesions form in the skin folds. Lesions can appear in the armpit, under the breasts, and around the groin, buttocks, and genitals.
- ERYTHRODERMIC PSORIASIS Causing widespread redness with severe itching and pain, erythrodermic psoriasis can be life threatening.
Psoriasis frequently develops on the scalp and the nails. When it occurs on the scalp, psoriasis often causes silvery-white scale, which may be misdiagnosed as dandruff. Psoriatic nails frequently have tiny pits. The nails may loosen, thicken, or crumble. These signs may be misdiagnosed as a nail infection. Both scalp psoriasis and nail psoriasis can be difficult to treat.
Psoriatic Arthritis
Between 10% and 30% of people who develop psoriasis get a related form of arthritis called “psoriatic arthritis;’ which causes inflammation of the joints. Psoriatic arthritis is a lifelong condition that causes deterioration, pain, and stiffness in the joints. Medication can help prevent joint deformities and disability if used early. Without treatment, permanent joint degeneration and destruction can occur.
Diagnosing Psoriasis
Dermatologists diagnose psoriasis by examining the skin, nails and scalp. A skin biopsy may be taken to confirm the diagnosis.
Treatment of Psoriasis
While psoriasis cannot be cured, a number of treatment options can help control psoriasis. A patient’s health, age, lifestyle, and the severity of the psoriasis determine which treatment options are appropriate. Gaining control over the psoriasis may require different types of treatment and several visits to your dermatologist. To help patients control psoriasis, a dermatologist may prescribe medications to apply to the skin. These medications may contain cortisone compounds, retinoids, tar, or anthralin. These may be used in combination with natural sunlight or another ultraviolet (UV) light treatment. The more severe forms of psoriasis may require oral or injectable medications with or without UV light treatment.
Types Of Treatment
Topicals
- Corticosteroids (cortisone) — Cortisone is a medication that reduces inflammation. Cortisone creams, Ointments, and lotions may clear the skin temporarily and control the condition in many patients. Weaker preparations should be used on more sensitive areas of the body such as the genitals, armpits and face. Stronger preparations will usually be needed to control lesions on the scalp, elbows, knees, palms, sales, and parts of the torso. Dressings may be applied to enhance the effectiveness of the medication. Corticosteroids must be used cautiously and with your dermatologist’s instruction. Side effects of the stronger cortisone preparations include thinning of the skin, dilated blood vessels, bruising, stretch marks, and skin color changes. Stopping these medications suddenly may result in a flare-up of the disease. When used for many months, psoriasis can become resistant to the corticosteroid. Difficult-to-treat spots may be treated with an injection of a corticosteroid.
- Anthralin — Often effective on tough·to-treat thick patches of psoriasis, anthralin decreases the skin’s rapid growth rate and reduces inflammation. Newer preparations and treatment methods minimize the traditional side effects of skin irritation and staining.
- Calcipotriene — Useful for individuals with localized psoriasis, calcipotriene may be combined with other treatments. Be sure to apply calcipotriene as instructed by your dermatologist to avoid side effects, such as skin irritation.
- Retinoids — This medication may be used alone or in combination with topical corticosteroids for treatment of localized psoriasis. Women who are, or may become, pregnant should not use topical retinoids.
- Coal Tar — For more than 100 years, coal tar has been used safely and effectively to treat psoriasis. Today’s products are greatly improved and less messy. Stronger prescriptions can be made specifically to treat difficult areas.
Light Therapy
Ultraviolet (UV) light, which is found in sunlight, slows the rapid growth of skin cells. Patients with psoriasis may receive light therapy treatments at a dermatologist’s office, psoriasis center, or hospital. Psoriasis patients who live in warm climates may be directed to carefully sunbathe. Under a dermatologist’s care, light therapy offers many patients a safe and effective treatment option. Seek the advice of your dermatologist before self·treating with natural or artificial UV light. Patients who receive light therapy at a medical facility may receive UVB light therapy, PUVA, or the Goeckerman treatment.
- Ultraviolet B (UVB) Light — This treatment exposes the skin to a wavelength of UV light called UVB. The therapy may be used alone or in combination with topical or systemic treatments. To receive UVB therapy, a patient either enters a light box that surrounds the patient or stands in front of a light panel. About 24 treatments over a two-month period are needed for clearing. Although UVB is very safe and effective, it does have possible side effects that include burns, freckling, and premature aging. Risks of skin cancer appear to be no greater than the risk caused by sun exposure.
- PUVA — An acronym, PUVA stands for “psoralen + UVA,” which are the two components of this treatment. Used to treat widespread psoriasis and psoriasis that has not responded to other therapies, PUVA is effective in approximately 85% of cases. To receive PUVA, a patient is given a drug called psoralen, which may be taken orally or applied to the psoriasis. The patient is then exposed to a carefully measured amount of a special form of ultraviolet A (UVA) light. Because psoralen remains in the lens of the eye, patients must wear UVA-blocking eyeglasses when exposed to sunlight from the time the psoralen is taken until sunset that day. Clearing usually occurs after approximately 25 PUVA treatments, which are given over a two- or three-month period. Keeping psoriasis under control requires about 30 to 40 treatments a year. PUVA treatments over a long period increase the risk of premature aging, freckling, and skin cancer. Dermatologists and their staff monitor PUVA treatment very carefully.
- Goeckerman Treatment — Named after the Mayo Clinic dermatologist who first reported it, this treatment combines coal tar dressings with UV light. Used to treat patients with severe psoriasis, Goeckerman treatment is performed daily for a prescribed amount of time. UV exposure times vary with the type of psoriasis and the sensitivity of the patient’s skin. Access to this therapy is limited because only a few specialized centers in the United States offer it.
Systemic Therapies
- Methotrexate — This anti-cancer medication can dramatically clear psoriasis. Because methotrexate can cause serious side effects, particularly liver disease, it is reserved for treating moderate to severe psoriasis that has not responded to other therapies. Patients taking methotrexate receive regular blood tests. Chest x-rays and occasional liver biopsies may be required. Other side effects include upset stomach, nausea, and dizziness. Methotrexate should not be used by pregnant women, nor by men or women who are trying to conceive a child. Conception should be avoided for at least12 weeks after stopping methotrexate. Patients who take methotrexate should not drink alcoholic beverages.
- Retinoids — An oral retinoid may be prescribed alone or in combination with ultraviolet light for severe cases of psoriasis. Side effects include dryness of the skin, lips and eyes; elevation of fat levels in the blood (cholesterol and triglycerides); and formation of tiny bone spurs. Oral retinoids can cause birth defects and should not be used by pregnant women, or women who intend to become pregnant during or within three years of discontinuing therapy. Patients taking an oral retinoid require close monitoring, which includes regular blood tests.
- Cyclosporine — This medication suppresses the immune system and is used to prevent rejection of a transplanted organ, such as a liver or kidney. While cyclosporine proves extremely effective in treating psoriasis, it is generally reserved for patients with severe psoriasis who have not responded to other therapies. Due to potential side effects, kidney function and blood pressure must be checked before the drug can be prescribed. Patients taking cyclosporine require close medical monitoring, which includes regular blood tests.
Biologic Agents
Biologics are systemic medications that are given by injection or infusion. What makes biologics unique is that these drugs pinpoint precise immune responses involved with psoriasis. For this reason, careful consultation with your dermatologist is important as there are a variety of treatments and combinations of treatments to consider and many medical tests to undergo before finding the most appropriate biologic treatment. The biologics used to treat psoriasis are:
- Alefacept — By blocking the over-activated T cells, alefacept can treat moderate to severe chronic plaque psoriasis. A medical professional must give each treatment of alefacept by an intramuscular injection (1M), which is used to deliver medication deep into large muscles of the body. The patient typically receives one injection per week for 12 weeks.
- Etanercept — For the treatment of psoriasis and psoriatic arthritis, this biologic agent blocks tumor necrosis factor-alpha (TNF-a), a messenger in the immune system that directs cells to cause the inflammation that leads to psoriasis. Given by subcutaneous (under the skin) injection, which patients can learn to give themselves, etanercept is typically used as long-term therapy.
- Efalizumab — For the treatment of psoriasis, this biologic blocks the T cells from becoming activated. Without this T cell activation, psoriasis can improve. Also meant to be used as long-term therapy, patients can learn how to give themselves these injections.
- Infliximab — For the treatment of psoriasis and psoriatic arthritis, this biologic blocks TNF-x:. It is given as an infusion, so the treatment must be given in a medical office.
- Adalimumab — This biologic blocks TNF,a. and ,is, effective in treating psoriatic arthritis. Patients can learn how to give themselves adalimumab, which is given by subcutaneous injection. A dermatologist is a physician who specializes in treating the medical, surgical and cosmetic conditions of the skin, hair and nails.