This
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:
-
Plaque
psoriasis--Skin lesions are red at the base and
covered by silvery scales.
-
Guttate
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 bacteria).
-
Pustular
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.
-
Inverse
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.
-
Erythrodermic
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.
-
Psoriatic
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.
Topical Treatment
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.
-
Corticosteroids--These
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.)
-
Calcipotriene--This
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 levels.
*
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.
-
Retinoid--Topical
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.
-
Coal
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.
-
Anthralin--Anthralin
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.
-
Salicylic
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.
-
Clobetasol
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.
-
Bath
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.
-
Moisturizers--When
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.
Light
Therapy
Natural
ultraviolet light from the sun and controlled delivery of
artificial ultraviolet light are used in treating psoriasis.
-
Sunlight--Much
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 the disease.
-
Ultraviolet
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.
A
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.
-
Psoralen
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.
-
Light
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.
Systemic
Treatment
For
more 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.
-
Methotrexate--Like
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.
-
Retinoids--A
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 are discontinued.
-
Cyclosporine--Taken
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.
-
6-Thioguanine--This
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.
-
Hydroxyurea
(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 birth defects.
-
Alefacept
(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.
-
Etanercept
(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.
-
Antibiotics--These
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.
Combination
Therapy
There
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.
Psychological
Support
Some
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 (FDA).
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
Phone: 301-495-4484
TTY: 301-565-2966
Fax: 301-718-6366
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)
Fax: 947-330-0050
www.aad.org
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
www.psoriasis.org
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.
Acknowledgments
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.
Additional information can be
found on the NIAMS Web site at niams.nih.gov
NIH Publication No. 03-5040
Common typos:
psoraisys, psriasis, psoriacys, psoiasis, psoraicys, psorasis,
psoliacys, psorisis, psoriais, psoriass, psoriacis, psoraicis,
psoliacis, poriasis, psoriasus, psoraisus, psoraisee, psoliasee,
psoriacee, psoraicee, psoriacus, psoraicus, psoliacus, psoriasee,
psoreasis, psoreasus, psoreacis, psoriassi, psoriaiss, psorisais,
psoirasis, psroiasis, posriasis, sporiasis, psoriasi, soriasis,
psoreasys, psoreasee,
psoraisis, psoriasys
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