Psoriasis and its management
Although psoriasis occurs globally, its prevalence varies in different populations. The prevalence of psoriasis in adults ranges from 0.91 to 8.5 percent, and the prevalence of the disease in children ranges from 0 to 2.1 percent. Certain ethnic groups like Japanese have a low prevalence of the disease, whereas it may be absent in aboriginal Australians and Indians from South America.
Psoriasis can be present at any age. It has even been reported at birth. The course and progress of the disease is unpredictable. Psoriasis has a genetic basis with the involvement of multiple genes.
Psoriasis is a chronic auto-immune disease of the skin that speeds up the growth cycle of skin cells. It is mostly present in adults but children can also get it. Men and women seem to have an equal risk. The disease is not contagious.
Types of psoriasis – There are basically five types –
Plaque psoriasis – It is the most common form and occurs as raised red patches covered with silvery white scales (dead skin cells). These patches commonly appear on the scalp, knees, elbows and lower back. They are often itchy and painful and they can crack and bleed.
Guttate psoriasis – This type often starts in childhood or young adulthood. This is the second most common type of psoriasis, prevailing in about 10% of the patients.
Inverse psoriasis – Also known as intertriginous and flexural psoriasis, it shows up as very red patches in body folds which are smooth and shiny. This type may also be associated with another type anywhere in the body.
Pustular psoriasis – It is characterized by white pustules (blisters) surrounded by red skin. The pus consists of white blood cells. It is not an infection and is, therefore, not contagious.
Erythrodermic psoriasis – This is an inflammatory form of psoriasis, often affecting most of body surface. It is a rare type occurring once or more during the lifetime of 3 percent of people who have psoriasis. It generally appears on people who have unstable plaque psoriasis. Widespread, fiery redness and exfoliation of the skin characterize this form. Severe itching and pain often accompanies it. It may require hospitalization.
Signs and symptoms – Typically, they depend on the specific type.
Plaque psoriasis – The following are the common signs and symptoms -
- Raised, reddish patches on the skin called plaques.
- Patches may be covered with a silvery-white coating, which dermatologists call scale.
- Patches can appear anywhere on the skin.
- Most patches appear on the knees, elbows, lower back, and scalp.
- Patches can itch.
- Scratching the itchy patches often causes the patches to thicken.
- Patches vary in size and can appear as separate patches or join together to cover a large area.
- Nail problems — pits in the nails, crumbling nail; nail falls off.
Guttate psoriasis – The following are the common signs and symptoms –
- Small, red spots (usually on the trunk, arms, and legs but can appear on the scalp, face, and ears).
- Spots can show up all over the skin.
- Spots often appear after an illness, especially streptococcal infection of the throat.
- Spots may clear up in a few weeks or months without treatment.
- Spots may appear where the person had plaque psoriasis.
Inverse psoriasis – The following are the common signs and symptoms –
- Smooth, red patches of skin which look raw.
- Patches only develop where skin touches skin, such as the armpits, around the groin, genitals, and buttocks. Women can develop a red, raw patch under their breasts.
- Skin feels very sore where inverse psoriasis appears.
Pustular psoriasis – Its common signs and symptoms are as follows –
- Bright-red skin.
- Been feeling sick and exhausted.
- Severe itching.
- Rapid pulse.
- Loss of appetite.
- Muscle weakness.
Erythrodermic psoriasis –
- Skin looks like it is burned.
- Most (or all) of the skin on the body turns bright red.
- Body cannot maintain its normal temperature of 98.6° F. Person gets very hot or very cold.
- Heart beats too fast.
- Intense itching.
- Intense pain.
If a person has erythrodermic psoriasis, get the person to the hospital right away because his or her life may be in danger.
Treatment – There is no cure for psoriasis but the treatment will usually keep the condition under control. Treatments are determined by the type and severity of the psoriasis and the area of skin affected. A wide range of treatments are available for psoriasis but identifying, which treatment is most, effective can be difficult. Treatments fall into three categories:
Topical – It includes creams and ointments that are applied to your skin. They include emollients (moisturizes), topical steroids, tar preparations in the form of creams or ointments or shampoos, preparations of dithranol and preparations of vitamin D and vitamin A analogues. The topical drugs should be used under the instructions of the doctor, who is well versed in the management of psoriasis.
Phototherapy - The skin is exposed to certain types of ultraviolet light, which slow the rapid growth of new skin cells. There are two types of ultraviolet light therapy as mentioned below:
Ultraviolet A (UVA) –
UVA penetrates deeper into the skin than UVB.
- Treatment with UVA typically takes 20 minutes for a session.
- UVA light used with psoralen drugs is called PUVA. With PUVA, the treatment time is greatly reduced, from 20 minutes to about 2 minutes.
Ultraviolet B (UVB) –
It is more effective than UVA light in the management of psoriasis.
- Exposure times start at 30 to 60 seconds which are gradually increased until the light causes the skin to turn bright red. When the skin no longer turns red after this much exposure, the time is increased
- The treatments are given daily or several times a week.
- UVB light is used alone, with tar products or with anthralin applied to the skin.
The body is exposed to UV light from banks of light tubes that give off either UVB or UVA light in a booth. Booths come in several designs. Some look like phone booths, in which one can stand. Others look like tanning beds, on which one can lie down during treatment. The booth will record the total amount of light you are exposed to. The patient will wear sunglasses or a blindfold that will block UV light to protect eyes from getting cataracts. Men may also need to shield their genitals to protect them from an increased risk of genital cancer.
Systemic – It includes oral and injected medications that work throughout the entire body. Most people who use these drugs have moderate to severe psoriasis or psoriatic arthritis. Cyclocerine is a common immunosuppressant that stops the activity of certain immune cells which slows the growth of skin cells. It is taken orally and can provide rapid relief from symptoms. It should be avoided in persons, who have compromised immune system, have active serious infections or have abnormal kidney functions. It should also be avoided in women who are breastfeeding. People taking cyclocerine are also at an increased risk of developing lymphomas and other cancers. Methotrexate is another immunosuppressant drugs used commonly. This drug too has side-effects and pre-cautions. Soriatane, which is a synthetic form of vitamin A, is also used in psoriasis.
Other systemic medications used for the treatment of psoriasis include hydrourea (an oral cancer medication), isotretinoin (a synthetic form of vitamin A), mycophenolatemofetil, NSAIDS (nonsteroidal anti-inflammatory drugs), sulfsalazine, 6-thioguanine. All these medications have their own limitations, which demand caution at the level of physician as well as patient.
A newer class of drugs called biologics is also effective in the treatment of psoriasis. A biologic is a drug or vaccine that comes from the living sources such as human or animal proteins. They are administered either by injection or intravenous (IV) infusion. The commonly used biologics are Adalimumab (Humira), Etanercept (Enbrel), Golimumab (Simponi), Infliximab (Remicade) and Ustekinumab (Stelara). They work well to treat moderate to severe psoriasis.
Psoriasis is a chronic auto-immune disease of the skin which is mostly present in adults but children can also be affected by it. It is not contagious. Psoriasis is basically of five types, the commonest type being plaque psoriasis. Erythrodemic psoriasis may carry a risk to life. Its management includes topical applications, phototherapy and systemic drugs.