What is psoriasis?

Psoriasis is a common and recurring condition in which the skin develops red patches of various sizes, covered with dry, silvery scales. Most often it affects the scalp, the trunk of the body and the outer side of the arms and legs, especially the elbows and knees. The palms, soles and nails may also be involved. It can also affect the folds (inverted psoriasis). Fortunately the face is often spared.

What causes psoriasis?

Psoriasis is not an infection and cannot be caught from someone else. Be assured that you are not contagious to others.

Although psoriasis is one of the oldest skin conditions known to man, its cause is still not completely known. Luckily today, however, we do have more information as to its development.

The epidermis or outer layer of our skin is constantly manufacturing new cells and shedding old ones. Normally the development of new epidermal cells which grow out from the base epidermis to the skin surface takes about 28 days. In psoriasis, the process is sped up to 4 or 5 days. Instead of shedding well-formed cells inconspicuously, the outer cells are poorly formed, resulting in scales which remain heaped up on the skin.

Can anyone develop psoriasis?

Psoriasis is seen in about 1 out of 50 individuals. There are some factors that seem to determine who is most likely to get psoriasis, and possibly the most important of these is heredity. Often, the person with psoriasis has a parent or grandparent who has also had the condition. It has been estimated that a person with one affected parent has approximately a 30% chance of being affected. If both parents have suffered with psoriasis, the chances increase to approximately 70%. Because one family member has severe psoriasis does not mean that other individuals will have psoriasis to the same degree and, in fact, others may have only mild cases or almost undetectable spots. Psoriasis is a very unpredictable disorder and can occur at any time in life, but most commonly between the ages of 15 and 50.

How is psoriasis diagnosed?

The white, silvery scale of psoriasis is so distinctive that it is relatively easy to diagnose. When the scales are not evident, scratching the lesions will show typical scales. The physician may lift or scrape the lesion to assess bleeding points, a characteristic of psoriasis. In about 25% of all cases, the nails may also show peculiar changes. There may be little holes or pits or a lack of luster with thickening scales collecting at the nail tip.

These characteristics, plus the distribution of the scaly patches on the body and the family history will lead to a diagnosis. When in doubt, a biopsy - the microscopic examination of a tiny skin piece removed under local anesthesia - will provide confirmation.

What differentiates psoriasis of the scalp from plain dandruff?

Dandruff covers most of the scalp while psoriasis usually occurs in definite spots with normal scalp in between. These spots often end beyond the scalp margin and have well-defined borders. By passing your finger over the scalp, you cannot feel dandruff; you can only see the flakes on your shoulders. With psoriasis you can, however, feel the psoriatic lump caused by heaped up scales held together by the hairs.

Will psoriasis on the scalp cause loss of hair?

It is more a breaking of hair than a true hair loss. The roots, which are deep down in the skin, are not affected. Once your scalp is clear of scales, the hair will grow as healthy as before.

What is the importance of "nerves" in psoriasis?

Stress or bad "nerves" do not cause psoriasis but can aggravate or perpetuate the disease.

Do infections affect psoriasis?

A bacterial sore throat in children often triggers an attack of psoriasis. This is usually a particular type of psoriasis called "guttate", meaning "drop-like" in Latin. The red, flaky spots - instead of being solid patches - are round and small and resemble drops of water sprinkled over the body.

In addition, an adult with chronic psoriasis may develop a flare-up a few weeks after an infection (including a sore throat).

Do hormones affect psoriasis?

We know that there is some relationship. In both men and women, psoriasis develops more frequently or gets worse after puberty, and there is another smaller peak at menopause. Often the lesions improve or disappear during pregnancy, only to reappear after childbirth.

How about diet?

In general, over-weight individuals respond better to therapy if they lose weight. Some people have flare-ups following an excess of alcoholic drinks. A well-balanced diet is advisable for people with psoriasis, as it is for everyone.

What is the role of climate and sunlight?

A hot, humid environment tends to make bad cases of psoriasis worse. In contrast, a dry, sunny climate, as a rule, is beneficial for psoriasis patients, particularly those with mild cases. In temperate climates, where sunlight is not available all year, artificial ultraviolet light is frequently used in psoriasis treatment. If you are using artificial light at home, you must carefully follow the physician's and manufacturer's directions. Do not fall asleep under an artificial light source. Make sure the exposure is timed. It must be remembered that the redness from ultraviolet exposure takes 4 to 6 hours to reach a maximum and if you burn yourself, you will aggravate your psoriasis and in fact may induce a flare-up. Eye protection should always be worn.

Therapy combining ultraviolet light with either tar or anthralin is often used in hospital or out-patient settings. Because they make you more sensitive to light, it is very important to pay attention to the dose of light given and the dose increments that may be recommended, depending on your response to treatment.

Would a day at the beach be therapeutic?

Only if you are careful. You must remember that the redness from ultraviolet light takes 4 to 6 hours to reach a maximum, yet you may be more sensitive than you expect. (Sunlight is strongest between the hours of 10 a.m. and 3 p.m.) The time interval of sun exposure can be gradually increased provided nothing more than a pink colour is produced with exposure. Prolonged exposure to sunlight may do considerable harm especially if you are fair-skinned. A severe sun burn may actually cause psoriasis to spread all over the sun-burned areas.

Why does that happen?

In some people with psoriasis, an unusual phenomen may take place: superficial injury to the normal skin may cause it to develop a plaque of psoriasis at the injury site. Bad sunburn is one such injury. Others are scrapes or scratches. Occasionally, reactions to drugs, infections or other trauma, along with unknown factors, may also be responsible for psoriasis developing over the whole body.

What other complications should I know about?

Psoriasis may be associated with arthritis in about 10% of patients. This arthritis may involve only one or two joints in the hands, feet, arms and legs. Alternatively, lower back pain or other arthritic symptoms may be noted. If you have pain or swelling in a joint, you should make sure that your doctor knows you have psoriasis.

What can I expect from treatment?

Topical agents are the mainstay of psoriasis treatment. They are the safest and most effective long-term treatment for the vast majority of psoriatic patients. Many of these contain corticosteroids and are available in the appropriate strengths necessary to control the disease. Psoriasis plaques will frequently disappear entirely, or the disease will retreat to a few spots on the elbows or knees. Because skin is thinner on the face and in fold areas of the body, weaker steroids are often used at these locations to avoid thinning of the skin or the formation of stretch marks.

Topical corticosteroids can often be combined with tar derivatives or salicylic acid to increase their effect. Various tars or anthralin are often combined with artificial light (UVB) in a hospital or out-patient setting. Topical retinoids, Vitamin D analogs, and medicated tar shampoos are also used frequently.

When are oral medications prescribed?

Oral medications (treatments taken by mouth) such as methotrexate, acitretin and cyclosporin are reserved for severe or generalized psoriasis that does not respond to topical treatments.

All of the oral medications have a number of side effects. These drugs can be discussed further with your doctor, but it must be emphasized that they are only for patients with severe psoriasis who do not respond well to topical treatment.

The combination of psoralen taken orally with Ultraviolet A light treatment (known as PUVA) is also often prescribed. Light treatments have to be repeated on a frequent basis.

Is it true that psoriasis is incurable?

If a "cure" means making the disease disappear and never return, then psoriasis, like many diseases, is incurable. However, psoriasis can usually be controlled. This may take time. And certainly it takes patience and perseverance. Of course, individuals with a tendency to psoriasis may develop new lesions months or years later.

What kind of treatment will my doctor prescribe?

Your doctor knows best what is likely to help in your particular case. He or she will study your psoriasis and choose the measures that seem most suitable. Routine measures include various topical agents. Lamp treatments with ultraviolet light may be used in conjunction with topical medications.

What can I do to help?

  • Cooperate with your doctor. Set aside a certain amount of time daily for treatment. Apply the prescribed preparation to the affected skin in accordance with your physician's directions.
  • Try not to scratch. Scratching can actually bring on new psoriasis or make existing spots worse. Itching is seldom caused by psoriasis.
  • Avoid quick "cures". Often widely advertised, expensive unproven therapies which are said to have worked wonders with somebody else, are likely to fail when you use them. There is no known cure for psoriasis at the present time, although long remissions from disease can be obtained by following the appropriate treatments.
  • Avoid excessive stress. There is no doubt that individuals under a lot of stress or emotional upset will have an increased risk of having a flare-up of psoriasis.
  • Try to stop worrying about the unsightly appearance of the spots. It looks a lot worse to you than it does to other people. Besides, the more you worry, the worse the rash may get.
  • Watch your weight and alcohol consumption. Patients who are over-weight often have a more difficult time bringing the psoriasis under control and excess alcohol consumption will aggravate the problem as well.
  • Above all, be patient. Try not to be discouraged if progress is slow. If you are more stubborn than the disease, you can control it, make it disappear, or at least, keep it to a minimum.

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