Psoriasis:
Psoriasis is a skin disease that causes red, itchy scaly patches, most commonly on the knees, elbows, trunk and scalp. Psoriasis is a common, long-term (chronic) disease with no cure. It tends to go through cycles, flaring for a few weeks or months, then subsiding for a while or going into remission. Psoriasis is thought to be an immune system problem. Triggers include infections, stress and cold. The most common symptom is a rash on the skin, but sometimes the rash involves the nails or joints. Treatment aims to remove scales and stop skin cells from growing so quickly. Topical ointments, light therapy and medication can offer relief.
Symptoms
Psoriasis patches can range from a few spots of dandruff-like scaling to major eruptions that cover large areas. The most commonly affected areas are the lower back, elbows, knees, legs, soles of the feet, scalp, face and palms. Psoriasis signs and symptoms can vary from person to person. Common signs and symptoms include:
- Red patches of skin covered with thick, silvery scales
- Small scaling spots (commonly seen in children)
- Dry, cracked skin that may bleed or itch
- Itching, burning or soreness
- Thickened, pitted or ridged nails
- Swollen and stiff joints
Types of Psoriasis
Most types of psoriasis go through cycles, flaring for a few weeks or months, then subsiding for a time or even going into remission.
There are several types of psoriasis, including:
- Plaque psoriasis.The most common form, plaque psoriasis causes dry, raised, red skin patches (lesions) covered with silvery scales. The plaques might be itchy or tender, and there may be few or many. They usually appear on elbows, knees, lower back and scalp.
- Nail psoriasis.Psoriasis can affect fingernails and toenails, causing pitting, abnormal nail growth and discoloration. Psoriatic nails might loosen and separate from the nail bed (onycholysis). Severe cases may cause the nail to crumble.
- Guttate psoriasis.This type primarily affects young adults and children. It’s usually triggered by a bacterial infection such as strep throat. It’s marked by small, drop-shaped, scaling lesions on the trunk, arms or legs.
- Inverse psoriasis.This mainly affects the skin folds of the groin, buttocks and breasts. Inverse psoriasis causes smooth patches of red skin that worsen with friction and sweating. Fungal infections may trigger this type of psoriasis.
- Pustular psoriasis.This rare form of psoriasis causes clearly defined pus-filled lesions that occur in widespread patches (generalized pustular psoriasis) or in smaller areas on the palms of the hands or the soles of the feet.
- Erythrodermic psoriasis.The least common type of psoriasis, erythrodermic psoriasis can cover your entire body with a red, peeling rash that can itch or burn intensely.
- Psoriatic arthritis.Psoriatic arthritis causes swollen, painful joints that are typical of arthritis. Sometimes the joint symptoms are the first or only symptom or sign of psoriasis. And at times only nail changes are seen. Symptoms range from mild to severe, and psoriatic arthritis can affect any joint. It can cause stiffness and progressive joint damage that in the most serious cases may lead to permanent joint damage.
Causes
Psoriasis is thought to be an immune system problem that causes the skin to regenerate at faster than normal rates. In the most common type of psoriasis, known as plaque psoriasis, this rapid turnover of cells results in scales and red patches. Just what causes the immune system to malfunction isn’t entirely clear. Researchers believe both genetics and environmental factors play a role. The condition is not contagious.
When to see Doctor
If you suspect that you may have psoriasis, see your doctor. Also, talk to your doctor if your psoriasis:
- Becomes severe or widespread
- Causes you discomfort and pain
- Causes you concern about the appearance of your skin
- Leads to joint problems, such as pain, swelling or inability to perform daily tasks
- Doesn’t improve with treatment
Psoriasis Triggers
Many people who are predisposed to psoriasis may be free of symptoms for years until the disease is triggered by some environmental factor. Common psoriasis triggers include:
- Infections, such as strep throat or skin infections
- Weather, especially cold, dry conditions
- Injury to the skin, such as a cut or scrape, a bug bite, or a severe sunburn
- Stress
- Smoking and exposure to secondhand smoke
- Heavy alcohol consumption
- Certain medications — including lithium, high blood pressure medications and antimalarial drugs
- Rapid withdrawal of oral or systemic corticosteroids
Risk Factor
Anyone can develop psoriasis. About a third of instances begin in the pediatric years. These factors can increase your risk:
- Family history.The condition runs in families. Having one parent with psoriasis increases your risk of getting the disease, and having two parents with psoriasis increases your risk even more.
- Because stress can impact your immune system, high stress levels may increase your risk of psoriasis.
- Smoking tobacco not only increases your risk of psoriasis but also may increase the severity of the disease. Smoking may also play a role in the initial development of the disease.
Treatment
Psoriasis treatments aim to stop skin cells from growing so quickly and to remove scales. Options include creams and ointments (topical therapy), light therapy (phototherapy), and oral or injected medication.
Topical therapy
- Corticosteroids:These drugs are the most frequently prescribed medications for treating mild to moderate psoriasis. They are available as ointments, creams, lotions, gels, foams, sprays and shampoos. Mild corticosteroid ointments (hydrocortisone) are usually recommended for sensitive areas, such as your face or skin folds, and for treating widespread patches. Topical corticosteroids might be applied once a day during flares, and on alternate days or weekends only to maintain remission.
Your doctor may prescribe a stronger corticosteroid cream or ointment— triamcinolone (Acetonide, Trianex), clobetasol (Temovate) for smaller, less-sensitive or tougher-to-treat areas. Long-term use or overuse of strong corticosteroids can thin the skin. Over time, topical corticosteroids may stop working.
- Vitamin D analogues:Synthetic forms of vitamin D, such as calcipotriene and calcitriol (Vectical) slow skin cell growth. This type of drug may be used alone or with topical corticosteroids. Calcitriol may cause less irritation in sensitive areas. Calcipotriene and calcitriol are usually more expensive than topical corticosteroids.
- Retinoids:Tazarotene (Tazorac, Avage) is available as a gel and cream and applied once or twice daily. The most common side effects are skin irritation and increased sensitivity to light.
Tazarotene isn’t recommended when you’re pregnant or breast-feeding or if you intend to become pregnant.
- Calcineurin inhibitors:Calcineurin inhibitors — such as tacrolimus (Protopic) and pimecrolimus (Elidel) — reduce inflammation and plaque buildup. They can be especially helpful in areas of thin skin, such as around the eyes, where steroid creams or retinoids are too irritating or may cause harmful effects.
Calcineurin inhibitors are not recommended when you’re pregnant or breast-feeding or if you intend to become pregnant. This drug is also not intended for long-term use because of a potential increased risk of skin cancer and lymphoma.
- Salicylic acid:Salicylic acid shampoos and scalp solutions reduce the scaling of scalp psoriasis. It may be used alone, or to enhance the ability of other medications to more easily penetrate the skin.
- Coal tar:Coal tar reduces scaling, itching and inflammation. It’s available over-the-counter or by prescription in various forms, such as shampoo, cream and oil. These products can irritate the skin. They’re also messy, stain clothing and bedding, and can have a strong odor.
Coal tar treatment isn’t recommended for women who are pregnant or breast-feeding.
- Goeckerman therapy:Some doctors combine coal tar treatment with light therapy, which is known as Goeckerman therapy. The two therapies together are more effective than either alone because coal tar makes skin more receptive to UVB light.
- Anthralin:Anthralin (another tar product) is a cream used to slow skin cell growth. It can also remove scales and make skin smoother. It should not be used on the face or genitals. Anthralin can irritate skin, and it stains almost anything it touches. It’s usually applied for a short time and then washed off.
Light Therapy
- Sunlight:Brief, daily exposures to sunlight (heliotherapy) might improve psoriasis. Before beginning a sunlight regimen, ask your doctor about the safest way to use natural light for psoriasis treatment.
- UVB broadband:Controlled doses of UVB broadband light from an artificial light source can treat single patches, widespread psoriasis and psoriasis that doesn’t improve with topical treatments. Short-term side effects might include redness, itching and dry skin. Moisturizing regularly can help ease your discomfort.
- UVB narrowband:UVB narrowband light therapy might be more effective than UVB broadband treatment and in many places has replaced broadband therapy. It’s usually administered two or three times a week until the skin improves and then less frequently for maintenance therapy. Narrowband UVB phototherapy may cause more-severe and longer lasting burns, however.
- Psoralen plus ultraviolet A (PUVA):This treatment involves taking a light-sensitizing medication (psoralen) before exposure to UVA light. UVA light penetrates deeper into the skin than does UVB light, and psoralen makes the skin more responsive to UVA exposure.
This more aggressive treatment consistently improves skin and is often used for more-severe cases of psoriasis. Short-term side effects include nausea, headache, burning and itching. Long-term side effects include dry and wrinkled skin, freckles, increased sun sensitivity, and increased risk of skin cancer, including melanoma.
- Excimer laser:With this form of light therapy, a strong UVB light targets only the affected skin. Excimer laser therapy requires fewer sessions than does traditional phototherapy because more powerful UVB light is used. Side effects can include redness and blistering.
