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What is Eczema?
Eczema is a very common condition which in some form, at some
time, afflicts more than half the population. Eczema is simply an
inflammation of the skin, which can have many causes, but regardless
of the cause, the changes that occur in the skin are very similar.
Eczema may be acute or abrupt in onset and last only a limited time
or it may be slow in onset and persist for long periods of time. In
acute eczema the skin is swollen, red and scaly and on examination
under a microscope, large numbers of immune white blood cells are
seen to be accumulated in the skin. In chronic eczema the skin is
dry and scaly and as a result of scratching, it may become very thickened.
Infiltration of the skin by immune white cells is also found in chronic
eczema.
There has been much investigation of the mechanism and causes of eczema
but unfortunately it remains a poorly understood disorder. We know
there are several different causes of eczema, several of which are
inherited, but how some abnormality of a gene is translated into the
skin changes we see is unknown. It is important to distinguish between
the different types of eczema because the outlook and to some extent
the management, can be quite different.
A point on terminology: the terms eczema and dermatitis are used interchangeably
and common usage dictates a choice of terms.
The Different Types of Eczema
Atopic Eczema
An inherited condition which is associated with hay fever and asthma.
Some patients only have eczema while others have two or three of these
conditions. Atopic eczema can begin at any age but the commonest time
of onset is in childhood. The course of the condition is very unpredictable
and punctuated by frequent remissions and relapses.
Seborrheic Eczema
Also an inherited condition but the transmission of this trait is
rather random and frequently skips generations. Seborrheic eczema
is closely related to psoriasis and both conditions may be found in
the one family, or even in the same individual.
Dandruff is the mildest degree of seborrheic eczema. The addition
of redness and inflammation of the scalp to the flaking of dandruff
is the next stage. Seborrheic eczema can spread from the scalp to
the face, chest and other parts of the body so that it can be generalized
in some patients.
The development and spread of seborrheic eczema is partly a function
of the patient and partly a function of the environment. Other illnesses,
particularly those necessitating bed-rest, frequently are the trigger
for seborrheic eczema. Winter can also be a trigger factor. Recently,
evidence has accumulated that a yeast-like organism, which is a normal
resident on the skin, may be closely involved in the basic defect
in seborrheic eczema. Elimination of the organism is associated with
resolution of the eczema but, as yet, there is no safe and effective
way to achieve this.
Hand Eczema
This is in some ways the most disabling form of eczema because it
impedes the function of a particularly important part of our anatomy.
Three factors interact in causing hand eczema but the importance of
each one varies between individuals.
First, a genetic or inherited tendency to develop hand eczema probably
underlies all cases. A family history can be obtained in about 80%
of patients.
Second, contact with chemical irritants appears to be the trigger
for developing eczema in many patients and is an aggravating factor
in all patients.
For example, the commonest time of onset of hand eczema in women is
after the birth of the first child. At this time, increased housework,
in particular lots of laundry and wet work, is mainly responsible
for onset of the problem.
The third factor is nervous and emotional stress and this likewise
is the dominant cause in some people and plays some role in everybodys
hand eczema.
Winter Eczema
Many names have been used to describe this condition, but perhaps
this is the most descriptive term. Winter eczema mainly occurs in
that season and is confined to people with a tendency for dry skin.
Central heating giving a dry atmosphere, plus frequent, long, hot
showers with liberal use of soap are the trigger factors in this condition.
Winter eczema tends to become more common and more severe as we grow
older and this tendency is probably due to older skin being less able
to produce oil and retain moisture. In some elderly people winter
eczema persists year round.
The first change seen in the skin is some mild flaking which is associated
with itch. Soon redness, cracking and scaling appear. The commonest
sites for winter eczema are the flanks and the lower limbs but any
area can be affected.
Contact Eczema
The name of this condition explains its cause: it is
due to contact with a chemical to which one is allergic. The commonest
example is poison ivy dermatitis. The site of eczema is determined
by what portion of the body comes into contact with the offending
chemical since only skin that has had direct contact will be affected.
The duration of the problem depends on the duration and frequency
of contact with the chemical.
Thus, poison ivy dermatitis usually only lasts a few days, or at the
most a week or two, because in most instances it is triggered by a
single encounter with the chemical. In contrast, shoe dermatitis due
to a dye in leather may persist for months because of daily contact
and unawareness that a chemical is causing the problem.
Neurodermatitis
This is a term used rather loosely to refer to several types of eczema.
Chronic neurodermatitis usually consists of a single patch of eczema
with marked thickening of the skin located on the nape of the neck,
the back of a leg or the outer aspect of an arm. Another form of neurodermatitis
consists of nodules in the skin which are scattered over all parts
of the body.
The hallmark of neurodermatitis is intense itching and the consequent
scratching of the skin results in the thickening of the skin and the
formation of nodules. The name neurodermatitis implies that nerves
have something to do with this condition, but there is no evidence
that the nerves in the skin or nervous stress have anything to do
with the cause of this type of eczema.
The Diagnosis of Eczema
Eczema can usually be readily diagnosed from the history of the condition
plus examination of the skin. Microscopic examination of a small biopsy
of the skin can be used to provide confirmation of the diagnosis in
the few cases where doubt exists. If contact eczema is diagnosed,
patch tests are often required to detect what chemical is causing
the allergy, unless its identity is apparent from the history.
Treatment of Eczema
There are three aspects to the treatment of eczema: specific treatment
aimed at removing the cause; nonspecific treatment aimed at removing
aggravating factors and controlling symptoms; and suppressive treatment
aimed at suppressing the inflammation that is occurring in the skin.
Specific Treatment
Contact eczema is the only type of eczema for which a specific cause
is known. Once the chemical responsible for the eczema has been identified,
it must be eliminated form the environment of the patient and all
further contact should be avoided. For example, if poison ivy is thought
to be the cause of a patients eczema, that plant and related
species such as poison oak must be avoided in the future.
Non-Specific Treatment
Several measures can be very helpful in reducing the symptoms and
severity of eczema:
Moisturizers
The skin of patients with chronic eczema is usually very dry. Dry
skin tends to be itchy and this symptom can be reduced by frequent
application of moisturizers. The best time to apply a moisturizer
is immediately after a bath or shower since the amount of water in
the skin is maximal at that time and the moisturizer will help to
lock-in this water and prevent its evaporation.
The choice of a moisturizer is individual, some prefer an ointment,
some a cream and some a lotion. We have samples of different moisturizers
and will be pleased to let you try some. One important point: price
is a poor guide to quality of a moisturizer and the most expensive
is not necessarily the best for you.
Antipruritics
Itchiness, or pruritus as it is called, is a major symptom in all
people with eczema. There is a vast number of drugs listed as being
antipruritic and most are moderately successful in controlling itch.
Almost all antipruritic are antihistamines, which have two problem
side-effects: drowsiness and enhancement of the effects of alcohol.
When trying a new antipruritic you should first take it at home in
the evening to test whether it makes you drowsy. Always be cautious
of mixing antihistamines and alcohol and never mix antihistamines,
alcohol and driving; the combination may be lethal.
Antibiotics
Infection is often super-imposed on eczema and frequently elimination
of such infection can greatly reduce the severity of eczema. Short
and long courses of antibiotics may be required to combat infection.
Reduction of Irritants
There are a number of irritant factors in our environment which increase
the severity in patients with eczema involving the hands but apply
to all patients with eczema in a greater or lesser degree.
Here are a few simple rules to protect your hands and help reduce
eczema:
Whenever you must have your hands
in dirty or soapy water or in strong solutions, wear cotton gloves
covered with rubber gloves of adequate size. Rubber gloves with bonded
cotton linings are second best. Dust talc or corn starch inside the
gloves to absorb moisture. The gloves should not be worn for more
than 15 to 20 minutes at a time because the accumulated heat and perspiration
will be quite harmful to the skin. Use only water to rinse the gloves
and liners and see that they are dry before each use.
Use long-handled brushes as much as you can for cleaning and
scouring dishes, pots and pans.
When doing dry, dusty or dirty housework wear cotton gloves.
Babies may be bathed with bare hands unless the hands are actually
inflamed.
Avoid prolonged contact with fruit juices, fruits, vegetables
and raw meats. Use as many "convenience" foods as possible.
Avoid exposure to hair lotions, dyes, rinses, shampoos and tonics
with the bare hands. Gloves or Q-Tips may be used to apply these things
to the scalp.
Wash your hands as little as possible. When cleaning is necessary
just wipe them with a wash cloth and luke-warm water. Pat dry. Use
soap as little as possible and rinse thoroughly.
Discontinue the wearing of rings while the eczema is active.
Often the trouble starts under rings due to trapping of soap, detergent,
or other potentially irritating materials. Always rinse thoroughly
under your rings.
Suppressive Treatment
Elimination of inflammation in the skin will eliminate eczema. Anti-inflammatory
treatment is the main approach presently available for treating eczema.
But it is important to realize this is not a specific treatment since
it is not attacking the basic cause of eczema. Furthermore, if the
basic cause of an eczema continues to operate, anti-inflammatory treatments
will only be effective as long as they are used, or put another way,
suppression of the inflammation is a treatment and not a cure.
There are two effective anti-inflammatory treatments:
Cortisone Treatment
Cortisone is a hormone produced by the adrenal glands, which has,
as one of its effects, the property of reducing inflammation. Dozens
of derivatives of cortisone have now been produced and these have
greatly enhanced anti-inflammatory effects and reduced less desirable
effects. In the treatment of eczema these compounds are usually applied
to the skin as lotions, creams or ointments. When used as directed,
these preparations are safe and effective treatments but it must be
remembered that these are potent agents and misuse can result in very
undesirable side-effects. Thinning of the skin with formation of stretch
marks and broken blood vessels are two common problems from over use
of cortisone steroid medication.
Cortisone, as a compound called prednisone, is sometimes taken by
mouth for the treatment of eczema. In short courses, as for the treatment
of poison ivy dermatitis, this is a very effective and safe treatment.
However, long-term use in the treatment of chronic eczema is associated
with two inevitable problems. First, the effectiveness of the drug
diminishes so that more and more is required to produce the same effect.
Second, prednisone will eventually cause side effects in the form
of weakening of bones, cataracts and proneness to develop serious
infections such as pneumonia. Thus, prednisone is not a safe or effective
long-term treatment for eczema.
Ultraviolet Light
Psoralen in combination with ultraviolet A light (PUVA therapy) has
been used in the treatment of chronic eczema for the past 20 years.
The response rate varies with the type of eczema. About 75% of patients
with generalized atopic eczema have a good response after 20-30 treatments.
The reason for a failed response in the remaining 25% is not known.
Over 90% of patients with seborrheic eczema and hand eczema have a
good response after 20-30 treatments. Generalized winter-type eczema
in the elderly patients also usually responds.
PUVA therapy has three advantages over topical cortisone steroid ointments
and creams. First, a successful response to PUVA therapy results in
a return of the skin to a normal appearance without symptoms whereas
cortisone treatment only produces a partial suppression of the eczema.
Second, infrequent weekly or every other week treatment is usually
sufficient to maintain a clear state whereas cortisone treatment usually
has to be used daily. Finally, PUVA therapy does away with the bother
of applying potions and lotions to the skin.
Ultraviolet B light has also been used in the treatment of eczema
but it is less effective than PUVA therapy. Narrow-band UVB phototherapy,
a new treatment for eczema is more effective and will clear many patients
with eczema. It is a useful alternative to PUVA therapy.
Treatments That Do Not Work in Eczema
Desensitization
Desensitization has been used in atopic eczema in the belief that
allergy to various materials in the environment are the cause of the
condition. While it is true that people with atopic eczema often give
positive responses to pollens, grasses, dander etc. when tested by
the prick allergy testing, desensitization to these substances does
not improve the eczema.
Exclusion Diets
Exclusion diets have also been used in atopic eczema in the belief
that food allergy is the basic cause. Careful studies have shown these
diets are of no value apart from the placebo effect of "doing
something", exceppt in a select group of young children.
Sedatives, anti-depressants and other mood-altering
drugs
Sedative, anti-depressants and other mood-altering drugs of various
types have been popular, particularly in the treatment of neurodermatitis.
Unless there is other evidence for the diagnosis of a neurosis, little
or no improvement is achieved with this approach.
Vitamin and Mineral Supplements
Vitamin and mineral supplements have been advocated in the treatment
of various types of eczema. Eczema is not a manifestation of dietary
deficiency and dietary supplementation of any type is completely without
value in its treatments.
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