Questions and Answers about Psoriasis
booklet contains general information about psoriasis. It describes what
psoriasis is, what causes it, and what the treatment options are. If
you have further questions after reading this booklet, you may wish
to discuss them with your doctor.
What Is Psoriasis?
Psoriasis is a chronic (long-lasting) skin disease
of scaling and inflammation that affects 2 to 2.6 percent of the United
States population, or between 5.8 and 7.5 million people. Although the
disease occurs in all age groups, it primarily affects adults. It appears
about equally in males and females. Psoriasis occurs when skin cells
quickly rise from their origin below the surface of the skin and pile
up on the surface before they have a chance to mature. Usually this
movement (also called turnover) takes about a month, but in psoriasis
it may occur in only a few days. In its typical form, psoriasis results
in patches of thick, red (inflamed) skin covered with silvery scales.
These patches, which are sometimes referred to as plaques, usually itch
or feel sore. They most often occur on the elbows, knees, other parts
of the legs, scalp, lower back, face, palms, and soles of the feet,
but they can occur on skin anywhere on the body.
The disease may also affect the fingernails, the toenails,
and the soft tissues of the genitals and inside the mouth. While it
is not unusual for the skin around affected joints to crack, approximately
1 million people with psoriasis experience joint inflammation that produces
symptoms of arthritis. This condition is called psoriatic arthritis.
How Does Psoriasis Affect Quality of Life?
Individuals with psoriasis may experience significant physical discomfort
and some disability. Itching and pain can interfere with basic functions,
such as self-care, walking, and sleep. Plaques on hands and feet can
prevent individuals from working at certain occupations, playing some
sports, and caring for family members or a home. The frequency of medical
care is costly and can interfere with an employment or school schedule.
People with moderate to severe psoriasis may feel self-conscious about
their appearance and have a poor self-image that stems from fear of
public rejection and psychosexual concerns. Psychological distress can
lead to significant depression and social isolation.
What Causes Psoriasis?
Psoriasis is a skin disorder driven by the immune system, especially
involving a type of white blood cell called a T cell. Normally, T cells
help protect the body against infection and disease. In the case of
psoriasis, T cells are put into action by mistake and become so active
that they trigger other immune responses, which lead to inflammation
and to rapid turnover of skin cells. In about one-third of the cases,
there is a family history of psoriasis. Researchers have studied a large
number of families affected by psoriasis and identified genes linked
to the disease. (Genes govern every bodily function and determine the
inherited traits passed from parent to child.) People with psoriasis
may notice that there are times when their skin worsens, then improves.
Conditions that may cause flareups include infections, stress, and changes
in climate that dry the skin. Also, certain medicines, including lithium
and betablockers, which are prescribed for high blood pressure, may
trigger an outbreak or worsen the disease.
How Is Psoriasis Diagnosed?
Occasionally, doctors may find it difficult to diagnose psoriasis,
because it often looks like other skin diseases. It may be necessary
to confirm a diagnosis by examining a small skin sample under a microscope.
There are several forms of psoriasis. Some of these include:
psoriasis--Skin lesions are red at the base and covered
by silvery scales.
psoriasis--Small, drop-shaped lesions appear on the trunk,
limbs, and scalp. Guttate psoriasis is most often triggered by upper
respiratory infections (for example, a sore throat caused by streptococcal
psoriasis--Blisters of noninfectious pus appear on the
skin. Attacks of pustular psoriasis may be triggered by medications,
infections, stress, or exposure to certain chemicals.
psoriasis--Smooth, red patches occur in the folds of the
skin near the genitals, under the breasts, or in the armpits. The
symptoms may be worsened by friction and sweating.
psoriasis--Widespread reddening and scaling of the skin
may be a reaction to severe sunburn or to taking corticosteroids
(cortisone) or other medications. It can also be caused by a prolonged
period of increased activity of psoriasis that is poorly controlled.
arthritis--Joint inflammation that produces symptoms of
arthritis in patients who have or will develop psoriasis.
How is Psoriasis Treated?
Doctors generally treat psoriasis in steps based on the severity of
the disease, size of the areas involved, type of psoriasis, and the
patient's response to initial treatments. This is sometimes called the
"1-2-3" approach. In step 1, medicines are applied to the skin (topical
treatment). Step 2 uses light treatments (phototherapy). Step 3 involves
taking medicines by mouth or injection that treat the whole immune system
(called systemic therapy).
Over time, affected skin can become resistant to treatment, especially
when topical corticosteroids are used. Also, a treatment that works
very well in one person may have little effect in another. Thus, doctors
often use a trial-and-error approach to find a treatment that works,
and they may switch treatments periodically (for example, every 12 to
24 months) if a treatment does not work or if adverse reactions occur.
Treatments applied directly to the skin may improve
its condition. Doctors find that some patients respond well to ointment
or cream forms of corticosteroids, vitamin D3, retinoids, coal tar,
or anthralin. Bath solutions and moisturizers may be soothing, but they
are seldom strong enough to improve the condition of the skin. Therefore,
they usually are combined with stronger remedies.
drugs reduce inflammation and the turnover of skin cells, and they
suppress the immune system. Available in different strengths, topical
corticosteroids (cortisone) are usually applied to the skin twice
a day. Short-term treatment is often effective in improving, but
not completely eliminating, psoriasis. Long-term use or overuse
of highly potent (strong) corticosteroids can cause thinning of
the skin, internal side effects, and resistance to the treatment's
benefits. If less than 10 percent of the skin is involved, some
doctors will prescribe a high-potency corticosteroid ointment. High-potency
corticosteroids may also be prescribed for plaques that don't improve
with other treatment, particularly those on the hands or feet. In
situations where the objective of treatment is comfort, medium-potency
corticosteroids may be prescribed for the broader skin areas of
the torso or limbs. Low-potency preparations are used on delicate
skin areas. (Note: Brand names for the different strengths of corticosteroids
are too numerous to list in this booklet.)
drug is a synthetic form of vitamin D3 that can be applied to the
skin. Applying calcipotriene ointment (for example, Dovonex*) twice
a day controls the speed of turnover of skin cells. Because calcipotriene
can irritate the skin, however, it is not recommended for use on
the face or genitals. It is sometimes combined with topical corticosteroids
to reduce irritation. Use of more than 100 grams of calcipotriene
per week may raise the amount of calcium in the body to unhealthy
Brand names included in this booklet are provided as examples only,
and their inclusion does not mean that these products are endorsed
by the National Institutes of Health or any other Government agency.
Also, if a particular brand name is not mentioned, this does not
mean or imply that the product is unsatisfactory.
retinoids are synthetic forms of vitamin A. The retinoid tazarotene
(Tazorac) is available as a gel or cream that is applied to the
skin. If used alone, this preparation does not act as quickly as
topical corticosteroids, but it does not cause thinning of the skin
or other side effects associated with steroids. However, it can
irritate the skin, particularly in skin folds and the normal skin
surrounding a patch of psoriasis. It is less irritating and sometimes
more effective when combined with a corticosteroid. Because of the
risk of birth defects, women of childbearing age must take measures
to prevent pregnancy when using tazarotene.
tar--Preparations containing coal tar (gels and ointments)
may be applied directly to the skin, added (as a liquid) to the
bath, or used on the scalp as a shampoo. Coal tar products are available
in different strengths, and many are sold over the counter (not
requiring a prescription). Coal tar is less effective than corticosteroids
and many other treatments and, therefore, is sometimes combined
with ultraviolet B (UVB) phototherapy for a better result. The most
potent form of coal tar may irritate the skin, is messy, has a strong
odor, and may stain the skin or clothing. Thus, it is not popular
with many patients.
reduces the increase in skin cells and inflammation. Doctors sometimes
prescribe a 15- to 30-minute application of anthralin ointment,
cream, or paste once each day to treat chronic psoriasis lesions.
Afterward, anthralin must be washed off the skin to prevent irritation.
This treatment often fails to adequately improve the skin, and it
stains skin, bathtub, sink, and clothing brown or purple. In addition,
the risk of skin irritation makes anthralin unsuitable for acute
or actively inflamed eruptions.
acid--This peeling agent, which is available in many forms
such as ointments, creams, gels, and shampoos, can be applied to
reduce scaling of the skin or scalp. Often, it is more effective
when combined with topical corticosteroids, anthralin, or coal tar.
propionate--This is a foam topical medication (Olux), which
has been approved for the treatment of scalp and body psoriasis.
The foam penetrates the skin very well, is easy to use, and is not
as messy as many other topical medications.
solutions--People with psoriasis may find that adding oil
when bathing, then applying a moisturizer, soothes their skin. Also,
individuals can remove scales and reduce itching by soaking for
15 minutes in water containing a coal tar solution, oiled oatmeal,
Epsom salts, or Dead Sea salts.
applied regularly over a long period, moisturizers have a soothing
effect. Preparations that are thick and greasy usually work best
because they seal water in the skin, reducing scaling and itching.
ultraviolet light from the sun and controlled delivery of artificial
ultraviolet light are used in treating psoriasis.
of sunlight is composed of bands of different wavelengths of ultraviolet
(UV) light. When absorbed into the skin, UV light suppresses the
process leading to disease, causing activated T cells in the skin
to die. This process reduces inflammation and slows the turnover
of skin cells that causes scaling. Daily, short, nonburning exposure
to sunlight clears or improves psoriasis in many people. Therefore,
exposing affected skin to sunlight is one initial treatment for
B (UVB) phototherapy--UVB is light with a short wavelength
that is absorbed in the skin's epidermis. An artificial source can
be used to treat mild and moderate psoriasis. Some physicians will
start treating patients with UVB instead of topical agents. A UVB
phototherapy, called broadband UVB, can be used for a few small
lesions, to treat widespread psoriasis, or for lesions that resist
topical treatment. This type of phototherapy is normally given in
a doctor's office by using a light panel or light box. Some patients
use UVB light boxes at home under a doctor's guidance.
newer type of UVB, called narrowband UVB, emits the part of the
ultraviolet light spectrum band that is most helpful for psoriasis.
Narrowband UVB treatment is superior to broadband UVB, but it is
less effective than PUVA treatment (see next paragraph). It is gaining
in popularity because it does help and is more convenient than PUVA.
At first, patients may require several treatments of narrowband
UVB spaced close together to improve their skin. Once the skin has
shown improvement, a maintenance treatment once each week may be
all that is necessary. However, narrowband UVB treatment is not
without risk. It can cause more severe and longer lasting burns
than broadband treatment.
and ultraviolet A phototherapy (PUVA)--This treatment combines
oral or topical administration of a medicine called psoralen with
exposure to ultraviolet A (UVA) light. UVA has a long wavelength
that penetrates deeper into the skin than UVB. Psoralen makes the
skin more sensitive to this light. PUVA is normally used when more
than 10 percent of the skin is affected or when the disease interferes
with a person's occupation (for example, when a teacher's face or
a salesperson's hands are involved). Compared with broadband UVB
treatment, PUVA treatment taken two to three times a week clears
psoriasis more consistently and in fewer treatments. However, it
is associated with more shortterm side effects, including nausea,
headache, fatigue, burning, and itching. Care must be taken to avoid
sunlight after ingesting psoralen to avoid severe sunburns, and
the eyes must be protected for one to two days with UVA-absorbing
glasses. Long-term treatment is associated with an increased risk
of squamous-cell and, possibly, melanoma skin cancers. Simultaneous
use of drugs that suppress the immune system, such as cyclosporine,
have little beneficial effect and increase the risk of cancer.
therapy combined with other therapies--Studies have shown
that combining ultraviolet light treatment and a retinoid, like
acitretin, adds to the effectiveness of UV light for psoriasis.
For this reason, if patients are not responding to light therapy,
retinoids may be added. UVB phototherapy, for example, may be combined
with retinoids and other treatments. One combined therapy program,
referred to as the Ingram regime, involves a coal tar bath, UVB
phototherapy, and application of an anthralin-salicylic acid paste
that is left on the skin for 6 to 24 hours. A similar regime, the
Goeckerman treatment, combines coal tar ointment with UVB phototherapy.
Also, PUVA can be combined with some oral medications (such as retinoids)
to increase its effectiveness.
severe forms of psoriasis, doctors sometimes prescribe medicines that
are taken internally by pill or injection. This is called systemic treatment.
Recently, attention has been given to a group of drugs called biologics
(for example, alefacept and etanercept), which are made from proteins
produced by living cells instead of chemicals. They interfere with specific
immune system processes.
cyclosporine, methotrexate slows cell turnover by suppressing the
immune system. It can be taken by pill or injection. Patients taking
methotrexate must be closely monitored because it can cause liver
damage and/or decrease the production of oxygen-carrying red blood
cells, infection-fighting white blood cells, and clotenhancing platelets.
As a precaution, doctors do not prescribe the drug for people who
have had liver disease or anemia (an illness characterized by weakness
or tiredness due to a reduction in the number or volume of red blood
cells that carry oxygen to the tissues). It is sometimes combined
with PUVA or UVB treatments. Methotrexate should not be used by
pregnant women, or by women who are planning to get pregnant, because
it may cause birth defects.
retinoid, such as acitretin (Soriatane), is a compound with vitamin
A-like properties that may be prescribed for severe cases of psoriasis
that do not respond to other therapies. Because this treatment also
may cause birth defects, women must protect themselves from pregnancy
beginning 1 month before through 3 years after treatment with acitretin.
Most patients experience a recurrence of psoriasis after these products
orally, cyclosporine acts by suppressing the immune system to slow
the rapid turnover of skin cells. It may provide quick relief of
symptoms, but the improvement stops when treatment is discontinued.
The best candidates for this therapy are those with severe psoriasis
who have not responded to, or cannot tolerate, other systemic therapies.
Its rapid onset of action is helpful in avoiding hospitalization
of patients whose psoriasis is rapidly progressing. Cyclosporine
may impair kidney function or cause high blood pressure (hypertension).
Therefore, patients must be carefully monitored by a doctor. Also,
cyclosporine is not recommended for patients who have a weak immune
system or those who have had skin cancers as a result of PUVA treatments
in the past. It should not be given with phototherapy.
drug is nearly as effective as methotrexate and cyclosporine. It
has fewer side effects, but there is a greater likelihood of anemia.
This drug must also be avoided by pregnant women and by women who
are planning to become pregnant, because it may cause birth defects.
(Hydrea)--Compared with methotrexate and cyclosporine,
hydroxyurea is somewhat less effective. It is sometimes combined
with PUVA or UVB treatments. Possible side effects include anemia
and a decrease in white blood cells and platelets. Like methotrexate
and retinoids, hydroxyurea must be avoided by pregnant women or
those who are planning to become pregnant, because it may cause
(Amevive)--This is the first biologic drug approved specifically
to treat moderate to severe plaque psoriasis. It is administered
by a doctor, who injects the drug once a week for 12 weeks. The
drug is then stopped for a period of time while changes in the skin
are observed and a decision is made regarding the need or further
treatment. Because alefacept suppresses the immune system, the skin
often improves, but there is also an increased risk of infection
or other problems, possibly including cancer. Monitoring by a doctor
is required, and a patient's blood must be tested weekly around
the time of each injection to make certain that T cells and other
immune system cells are not overly depressed.
(Enbrel)--This drug is an approved treatment for psoriatic
arthritis where the joints swell and become inflamed. Like alefacept,
it is a biologic response modifier, which after injection blocks
interactions between certain cells in the immune system. Etanercept
limits the action of a specific protein that is overproduced in
the lubricating fluid of the joints and surrounding tissues, causing
inflammation. Because this same protein is overproduced in the skin
of people with psoriatic arthritis, patients receiving etanercept
also may notice an improvement in their skin. Individuals should
not receive etanercept treatment if they have an active infection,
a history of recurring infections, or an underlying condition, such
as diabetes, that increases their risk of infection. Those who have
psoriasis and certain neurological conditions, such as multiple
sclerosis, cannot be treated with this drug. Added caution is needed
for psoriasis patients who have rheumatoid arthritis; these patients
should follow the advice of a rheumatologist regarding this treatment.
medications are not indicated in routine treatment of psoriasis.
However, antibiotics may be employed when an infection, such as
that caused by the bacteria Streptococcus, triggers an outbreak
of psoriasis, as in certain cases of guttate psoriasis.
are many approaches for treating psoriasis. Combining various topical,
light, and systemic treatments often permits lower doses of each and
can result in increased effectiveness. Therefore, doctors are paying
more attention to combination therapy.
individuals with moderate to severe psoriasis may benefit from counseling
or participation in a support group to reduce self-consciousness about
their appearance or relieve psychological distress resulting from fear
of social rejection.
What Are Some Promising Areas of Psoriasis Research?
Significant progress has been made in understanding
the inheritance of psoriasis. A number of genes involved in psoriasis
are already known or suspected. In a multifactor disease (involving
genes, environment, and other factors), variations in one or more genes
may produce a greater likelihood of getting the disease. Researchers
are continuing to study the genetic aspects of psoriasis. Since discovering
that inflammation in psoriasis is triggered by T cells, researchers
have been studying new treatments that quiet immune system reactions
in the skin. Among these are treatments that block the activity of T
cells or block cytokines (proteins that promote inflammation). Several
of these drugs are awaiting approval by the U.S. Food and Drug Administration
Advances in laser technology are making it possible for doctors to
experiment with laser light treatment of localized plaques. A UVB laser
was recently tested in a study that was conducted at several medical
centers. Although improvements in the skin were noted, this treatment
is not without possible side effects. In some patients, the skin became
inflamed, blistered, or discolored following treatment.
Where Can People Find More Information About Psoriasis?
National Institute of Arthritis and Musculoskeletal and Skin Diseases
NIAMS/National Institutes of Health
1 AMS Circle
Bethesda, MD 20892-3675
NIAMS provides information about various forms of skin diseases; arthritis
and rheumatic diseases; and bone, muscle, and joint diseases. It distributes
patient and professional education materials and also refers people
to other sources of information. Additional information and updates
can be found on the NIAMS Web site.
American Academy of Dermatology
930 N. Meacham Road
P.O. Box 4014
Shaumburg, IL 60168-4014
Phone: 847-330-0230 or 888-462-DERM (3376) (free of charge)
This national professional association for dermatologists has a Web
site (PsoriasisNet) that contains basic information on psoriasis for
lay readers. Also included are press releases, answers to frequently
asked questions, information updates, and lists of dermatologists.
National Psoriasis Foundation
6600 SW 92nd Avenue, Suite 300
Portland, OR 97223
Phone: 503-244-7404 or 800-723-9166 (free of charge) Fax: 503-245-0626
The National Psoriasis Foundation provides physician referrals and
publishes pamphlets and newsletters that include information on support
groups, research, and new drugs and other treatments. The foundation
also promotes community awareness of psoriasis.
The NIAMS gratefully acknowledges the assistance of
Kevin D. Cooper, M.D., University Hospitals of Cleveland/Case Western
Reserve University, Ohio; Gerald Krueger, M.D., University of Utah,
Salt Lake City; Mark Lebwohl, M.D., The Mount Sinai Medical Center,
New York, New York; Laurence H. Miller, M.D., P.A., Chevy Chase, Maryland;
Alan N. Moshell, M.D., NIAMS; Robert Stern, M.D., Beth Israel Deaconess
Medical Center, Boston, Massachusetts; and the National Psoriasis Foundation
in the preparation of this and previous versions of this booklet.
The mission of the National Institute of Arthritis and
Musculoskeletal and Skin Diseases (NIAMS), a part of the Department
of Health and Human Services' National Institutes of Health (NIH), is
to support research into the causes, treatment, and prevention of arthritis
and musculoskeletal and skin diseases, the training of basic and clinical
scientists to carry out this research, and the dissemination of information
on research progress in these diseases. The National Institute of Arthritis
and Musculoskeletal and Skin Diseases Information Clearinghouse is a
public service sponsored by the NIAMS that provides health information
and information sources. Additional information can be found on the
NIAMS Web site at www.niams.nih.gov.
Publication Date: May 2003
NIH Publication No. 03-5040