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$Unique_ID{BRK04151}
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$Title{Psoriasis}
$Subject{Psoriasis Lichen Planus Pityriasis Rosea Eczema}
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Copyright (C) 1987, 1990, 1992 National Organization for Rare Disorders,
Inc.

468:
Psoriasis

** IMPORTANT **
It is possible the main title of the article (Psoriasis) is not the name
you expected.  Please check the SYNONYMS listing on the next page to find
alternate names, disorder subdivisions, and related disorders covered by this
article.

Synonyms

Information on the following disorders may be found in the Related
Disorders section of this report:

     Lichen Planus
     Pityriasis Rosea
     Eczema

General Discussion

** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.


Psoriasis is a common chronic and recurrent skin disorder characterized
by dry, well-circumscribed silvery gray scaling spots (papules) or plaques
which usually appear on the scalp, elbows, or knees.

Symptoms

Symptoms of Psoriasis usually begin between ages 10 and 40, but no age is
exempt.  The disorder tends to occur in families.  Symptoms may begin
gradually.   Recurrent outbreaks tend to vary in frequency and duration
according to severity of the case.  Psoriasis characteristically involves the
scalp, extremities (particularly the elbows and knees), the back and
buttocks.  The nails, eyebrows, armpit (axilla), navel, or anus and genital
region may also be affected.  In a few cases, the entire body may be
affected.

Sharply outlined lesions consist of red spots or plaques covered with
overlapping silvery gray shiny scales.  They usually do not itch.  These
lesions may heal without scarring and hair growth near the plaques is not
affected.  Papules sometimes extend and grow together, producing large
plaques in ring or spiral patterns.  Nail involvement may resemble a fungal
infection, with stippling, pitting, fraying or separation of the edges,
thickening, discoloration, and/or the appearance of debris under the nail
plate.  Psoriatic arthritis (which involves the joints in addition to the
skin symptoms), often closely resembles Rheumatoid Arthritis.  (For more
information on these disorders, choose "Psoriatic Arthritis" as your search
term in the Rare Disease Database and see the Arthritis section in the
Prevalent Health Conditions/Concerns area of NORD Services.)

In severe cases, Psoriasis lesions may appear in pustular form.  General
health usually is not affected, unless severe arthritis or untreatable
scaling develops.  However, stress may be caused by the stigma of an
unsightly skin disorder.

Causes

The exact cause of Psoriasis is not known, but the thick scaling is probably
due to increased skin cell proliferation.  A family history of Psoriasis is
common and usually reflects an autosomal dominant inheritance.  (Human traits
including the classic genetic diseases, are the product of the interaction of
two genes for that condition, one received from the father and one from the
mother.  In dominant disorders, a single copy of the disease gene (received
from either the mother or father) will be expressed "dominating" the normal
gene and resulting in appearance of the disease.  The risk of transmitting
the disorder from affected parent to offspring is 50% for each pregnancy
regardless of the sex of the resulting child.)

Affected Population

Psoriasis is a common disorder affecting about 2 to 4% of the United States
population.  Most of the affected individuals are of European heritage.
Psoriasis in people of African heritage is rare.

Related Disorders

Symptoms of the following disorders are similar to those of Psoriasis.
Comparisons may be useful for a differential diagnosis:

Lichen Planus is a recurrent, itchy, inflammatory skin eruption
characterized by small separate, angular spots that may coalesce into rough
scaly patches.  It is often accompanied by lesions in the mouth.  Women are
most commonly affected, and children are rarely affected.  The cause of this
disorder is unknown, though some minerals such as bismuth, arsenic, or gold,
or exposure to certain chemicals used in developing color photography may
cause an eruption indistinguishable from Lichen Planus.  (For more
information on this disorder, choose "Lichen Planus" as your search term in
the Rare Disease Database.)

Pityriasis Rosea is a self-limited, mild, inflammatory skin disorder
characterized by scaly lesions, most commonly on the trunk.  The disorder is
possibly due to an unidentified infectious agent.  It may occur at any age
but is seen most frequently in young adults.  In temperate climates,
incidence is highest during spring and autumn.

Eczema is a superficial inflammation of the skin, characterized by
blisters (when acute), redness, swelling (edema), oozing, crusting, scaling,
and usually itching.  Scratching or rubbing may lead to thickening of the
skin (lichenification).

Therapies:  Standard

The simplest forms of treatment for Psoriasis are lubricants, drugs which
dissolve the horn-like scales (keratolytics), and local corticosteroid drugs.
These are usually tried first because the number of effective remedies is
limited.  Exposure to sunlight is recommended, though occasionally sunburn
may induce eruptions in some people.  Systemic antimetabolic drugs should be
used only in severe cases with skin or joint involvement.  Systemic
corticosteroid drugs should not be used because of the side effects,
including worsening of skin lesions occurring either during or after therapy.

Lubricating creams, hydrogenated vegetable oils, or white petroleum jelly
(e.g. Vaseline) are applied alone or with added corticosteroid drugs,
salicylic acid, crude coal tar, or anthralin (dithranol) while the skin is
still damp after bathing.  Alternatively, crude coal tar ointment or cream
may be applied at night and washed off in the morning, followed by exposure
to natural or artificial (280 to 320 nm) ultraviolet light in slowly
increasing amounts.

Anthralin can be effective as an ointment applied carefully to the
lesions under a dressing which does not seal off the lesion completely at
bedtime.  It should be removed in the morning with mineral oil.  Anthralin
may be irritating and should not be used in folds of the skin such as the
neck, armpit and groin.  Anthralin stains sheets and clothing as well as the
skin.

Local corticosteroid drugs may be used as an alternative or in
combination with anthralin or coal tar treatment.  Corticosteroid creams such
as triamcinolone acetonide are most effective when used overnight with
waterproof plastic coverings or impregnated in adhesive tape.  A
corticosteroid cream may be applied without a plastic covering during the
day.  If potent fluorinated corticosteroids are applied to large areas of the
body, especially under a plastic covering, Psoriasis may be aggravated as
with systemic corticosteroids.  For small, localized lesions,
fluorandrenolide-impregnated tape left on overnight and changed in the
morning is usually effective.  Relapses may occur after application of local
corticosteroids more quickly than with other treatments.

Thick scalp plaques may be more difficult to treat.  A preparation
containing an oily solution of phenol and sodium chloride, or salicylic acid
in mineral oil may be rubbed in at bedtime with a toothbrush and washed out
the next morning with a detergent shampoo.  A shower cap can be worn in bed
to enhance penetration and to avoid staining.  Tar-containing shampoos are
often used.  Local corticosteroid lotions or gels may be applied during the
day.

Resistant skin or scalp patches may respond to local injections of a
suspension of the glucocorticoid drug, triamcinolone acetonide diluted with
saline solution.  However, these injections may cause local tissue shrinkage.

Psoralens and ultraviolet A (PUVA) is another treatment for severe
Psoriasis.  The sun-protecting drug methoxsalen (a psoralen compound) in oral
form is followed by exposure of the skin to long-wave ultraviolet light under
supervision of a dermatologist.  This therapy may produce remissions for
several months, but repeated treatments may cause skin cancer in some cases.

The cancer-fighting drug methotrexate, taken orally, is the most
effective treatment in the most severe cases of Psoriasis that are
unresponsive to other available therapies.  Methotrexate seems to interfere
with the rapid growth of skin cells.  Because the potential toxicity requires
careful monitoring of blood, kidney and liver function, and because dosage
regimens vary, methotrexate therapy should be carefully monitored by
physicians experienced in its use for Psoriasis.

The immunosuppressive drug cyclosporine (sandimmune) is used for short-
term treatment of severe psoriasis that has not responded to other standard
therapies such as UVB light treatment, methotrexate or etretinate.
Cyclosporine suppresses thre immune system, so long-term use and/or high
dosage can make a person vulnerable to other disorders.

Therapies:  Investigational

The retinoid drug etretinate (Tegison) has been used in Europe in the
treatment of Psoriasis, especially the pustular type, and in Psoriasis of the
hands and feet.  More research is necessary to establish effectiveness and
safety of retinoid drugs as a treatment for Psoriasis.

Clinical trials are underway to compare bath water PUVA therapy with of
other modalities in the treatment of Psoriasis.  Interested persons may wish
to contact:

     D. Martin Carter, Ph.D.
     Laboratory for Investigative Dermatology
     The Rockefeller University Hospital
     New York, NY  10021
     [phone]

to see if further patients are needed for this research.

This disease entry is based upon medical information available through
December 1992.  Since NORD's resources are limited, it is not possible to
keep every entry in the Rare Disease Database completely current and
accurate.  Please check with the agencies listed in the Resources section for
the most current information about this disorder.

Resources

For more information on Psoriasis, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     National Psoriasis Foundation
     6443 S.W. Beaverton Highway, Suite 210
     Portland, OR  97221

     Psoriasis Research Association
     107 Vista del Grande
     San Carlos, CA  94070

     The National Arthritis and Musculoskeletal and Skin Diseases Information
     Clearinghouse
     Box AMS
     Bethesda, MD  20892
     [phone]

For genetic information and genetic counseling referrals, please contact:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY  10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

INTERNAL MEDICINE:  Jay H. Stein, et al., eds.; Merck, Sharp & Dohme, 1982.
Pp. 1374-1377.

EFFECT OF CONTINUED ULTRAVIOLET B PHOTOTHERAPY ON THE DURATION OF
REMISSION OF PSORIASIS:  A RANDOMIZED STUDY:  R.S. Sterns, et al.; Journal Am
Acad Dermatol (September 1986:  issue 15(3)).  Pp. 546-552.