Psoriasis is a common skin condition that causes skin redness and irritation. Most people with psoriasis have thick, red skin with flaky, silver-white patches called scales.
Psoriasis can appear suddenly or slowly. Many times, it goes away and then comes back again and again.
- Irritated, red, flaky patches of skin
- Most often seen on the elbows, knees, and middle of the body
- Red patches may appear anywhere on the body, including 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 lesions in males
- Joint pain or aching
- Nail changes, including thick nails, yellow-brown nails, dents in the nail, and nail lifts off from the skin underneath
- Severe dandruff on the scalp
Psoriasis may affect any or all parts of the skin. 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 occurs 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.
Psoriasis is very common. Anyone can get it, but it most commonly begins between ages 15 and 35.
It is not contagious. You cannot spread it to others.
Psoriasis seems to be passed down through families. Doctors think it probably occurs when the body's immune system mistakes healthy cells for dangerous substances. See also: Inflammatory response
Usually, skin cells grow deep in the skin and rise to the surface about once a month. In persons with psoriasis, this process is too fast. Dead skin cells build up on the skin's surface.
The following may trigger an attack of psoriasis or make the condition more difficult to treat:
- Bacteria or viral infections, including strep throat and upper respiratory infections
- Dry air or dry skin
- Injury to the skin, including cuts, burns, and insect bites
- Some medicines, including antimalaria drugs, beta-blockers, and lithium
- Too little sunlight
- Too much sunlight (sunburn)
- Too much alcohol
In general, psoriasis may be severe in people who have a weakened immune system. This may include persons who have:
- Autoimmune disorders (such as rheumatoid arthritis)
- Cancer chemotherapy
- Some people with psoriasis may also have arthritis, a condition known as psoriatic arthritis.
There is no known way to prevent psoriasis. Keeping the skin clean and moist and avoiding your specific psoriasis triggers may help reduce the number of flare-ups.
Doctors recommend daily baths or showers for persons with psoriasis. Avoid scrubbing too hard, because this can irritate the skin and trigger an attack.
Sometimes, a skin biopsy is done to rule out other possible conditions. If you have joint pain, your doctor may order x-rays.
Psoriasis is a life-long condition that can be controlled with treatment. It may go away for a long time and then return. With appropriate treatment, it usually does not affect your general physical health.
Parapsoriasis can be managed conservatively, based on symptoms. Often, topical treatment is effective.
* Small plaque parapsoriasis usually is asymptomatic. Treatment should be based on alleviation of symptoms associated with scaliness. Patients should be reassured of the benign self-limiting nature of the disease.
- Emollients may be sufficient to treat scaliness; however, a trial of midpotency topical steroids (class 3-5) may lead to greater clinical responsiveness.
- Phototherapy is effective in treating lesions that are widely scattered. Broad- or narrow-band UV-B can be effective and can lead to remission. More recalcitrant presentations can be treated with psoralen and long-wave ultraviolet radiation (PUVA).
- Annual follow-up is recommended. An increase in the number of lesions, an increase in the size of lesions, or the development of induration or epidermal atrophy should prompt a repeat biopsy to consider a diagnosis of MF in evolution.
* Large plaque parapsoriasis should be treated because this may prevent progression to MF (CTCL).
- Therapy includes mid- to high-potency topical steroids (class 2-4), topical nitrogen mustard, and topical carmustine (BCNU). - Phototherapy with either broad- or narrow-band UV-B or PUVA can be effective in inducing remission.
- Follow-up every 6 months is recommended. Increasing number of lesions, increase in lesion size, or the development of induration or epidermal atrophy should prompt a repeat biopsy to consider a diagnosis of MF in evolution.