The Dermal System|
is a non-infectious, inflammatory disease of the skin, characterised by
well-defined erythematous plaques with
large, adherent, silvery scales. The
main abnormality in psoriasis is increased
epidermal proliferation due to excessive division of cells in the basal layers
and a shorter cell life cycle. The transit time of skin cells through the
epidermis is shortened and the epidermal turnover time falls from 28 to 5 or 6
days. Capillary dilation and increased vascularisation in the dermis always
accompany these lesions and are responsible for erythema.
of general population has psoriasis, it may start at any age but is often seen
between 15 and 40 years. The course of disease is unpredictable but is usually
chronic with exacerbations and
cause is unknown but the following
factors are involved:
There is frequently a genetic predisposition. A child with one affected parent
has a 25% chance of developing the disease and this rises to 60% if both
parents are affected. The type of inheritance is unclear but may be polygenic
or autosomal dominant with incomplete penetrance.
It is not known if biochemical abnormalities are the cause or result of
increased epidermal proliferation. There are increased levels of
prostaglandins, leukotrienes and their precursors. These may cause both the
increased cellular proliferation seen in psoriasis and the inflammatory
changes in the dermis. There are also various other biochemical abnormalities
which may contribute to the disease.
Many immunological abnormalities have been found but their role is uncertain.
Immune complexes with epidermal antigens have been detected in damaged skin.
One theory postulates that chronic irritation may uncover certain dermal
antigens which then initiate prolonged immune response. The dermal mononuclear
infiltrate is mainly of T lymphocytes, most of which are of the helper type.
Dermal. There is substantial evidence to suggest
that the increased epidermal cell proliferation of psoriasis is related to the
increased replication and metabolism of dermal fibroblasts, but the nature of
this link is unknown.
the basic defect, an individual may not inevitably develop psoriasis but
factors make this more likely. Although there appears to be no
obvious precipitating factor in about 70% of exacerbations of psoriasis, the
following factors are responsible for the minority of flare-ups:
Trauma, when the erupting lesions appear in areas of skin damage
such as scratches or surgical wounds (Koebner’s phenomenon).
Infection, especially streptococcal throat infection.
Sunlight; although UV light is usually therapeutic, 10% of
psoriatics become worse.
Drugs such as antimalarials, beta-blockers and lithium (for mania)
may worsen psoriasis.
Emotions such as anxiety seem to precipitate some exacerbations.
Clinical features: < BACK TO TOP >
occurs in several common patterns,
and typically there is no itching.
Plaque pattern is the most common type.
Individual lesions are irregular, well demarcated and range from a few
millimetres to several centimetres in diameter. The lesions are red
with dry and thin silvery-white
scaling, which may be obvious only
after scraping the surface. The elbows, knees, lower back and scalp are most
Guttate psoriasis (gutta is Latin for drop) is usually seen in children and adolescents.
The rash resembling drops of dark
red paint often appears rapidly and individual lesions are small and scaly. Bouts of
guttate psoriasis usually clear in a few months, but patients may develop the
plaque pattern later.
is often involved, presumably due to repeated trauma from brushing and
combing. Areas of marked scaling are interspersed with normal skin producing
lumpiness which is more easily felt than seen.
are frequently involved with nail pitting, change in colour, subungual
keratosis (thickening of the keratin layer under the nails) leading to
onycholysis (separation of the nail from the nail bed).
Flexures such as submammary and axillary folds show red, glistening and
symmetrical changes which characteristically are not scaly.
Erythrodermic psoriasis (exfoliative psoriatic dermatitis) is a less common
but serious pattern where the skin becomes universally red, thick and scaly,
with visible peeling. There is considerable increase in cutaneous blood flow
and heat loss with characteristic compensatory shivering.
There may be associated asymmetrical arthropathy affecting either the fingers and toes or a single large joint. This is called psoriatic arthritis; it often resembles rheumatoid arthritis and may be equally crippling.
Diagnosis: < BACK TO TOP >
Management < BACK TO TOP >
and reassurance are always necessary to deal with patient’s concerns
because anxiety sometimes can aggravate the disease.
is related to reduction of epidermal cell turnover since there is no known
lesions are usually treated with topical
keratolytic agents (salicylic acid in a gel form).
coal tar preparations in form of cream or shampoo [Polytar,
Alphosyl, Pinetarsol, Linotar, Alpha Keri Tar, Psorigel] probably act by
inhibiting DNA synthesis and therefore cell proliferation.
steroids are usually reserved for the face, ears, genitalia and
flexures, or for unresponsive psoriasis, but there is rapid relapse when they
are withdrawn and in time they start to lose their efficacy. Common
preparations are triamcinolone [Aristocort], fluocortolone [Ultralan],
betamethasone [Diprosone, Betnovate, Celestone], halcinonide [Halciderm],
mometasone [Elocon] and fluorometholone [Flucon, Flarex].
[Daivonex] is a non-steroidal antipsoriatic agent, derived from vitamin D
that suppresses proliferation of epidermal cells (keratinocytes), thus
reversing the abnormal keratinocyte changes in psoriasis; it is applied only
topically in form of cream.
radiation using medium-wave UV light (UVB) is often helpful, as well as
treatments available today:
photochemotherapy with PUVA (photosensitising agent psoralen + UVA long-wave
UV light) in specially designed cabins
retinoids-derivatives of vitamin A such as etretinate [Tigason] and
actitretin [Neotigason] (they are teratogenic and potentially hepatotoxic)
methotrexate [Ledertrexate, Methoblastin] is as cytotoxic agent that seems to interfere with the rapid proliferation of epidermal cells and is used in extensive psoriasis; haematologic, hepatic and renal function should be monitored
Prognosis < BACK TO TOP >
Nutrition < BACK TO TOP >
Nutrition that alleviate or prevent Psoriasis :-
Herbs < BACK TO TOP >
Herbs that alleviate or prevent Psoriasis :-
(source : -)
12 August 20096December 2005
speaker Mr NgThian Watt the Principal Trainer from
Napoleon Hill Associates MalaysiaDetails