Allergy Conditions
Skin – Skin Allergy
Contents
- Eczema
- Urticaria (Hives)
- Allergenic Causes Urticaria
- Non-AllergenicCauses of Physical Urticaria:
- * Dermatographism
- * Cold Urticaria
- * Heat Urticaria
- * Solar Urticaria
- Treatment
Allergies affecting the skin can result in eczema or urticaria (hives).
Eczema
This
condition is also called atopic dermatitis. This is largely a disease of
children but also affects adults. It usually starts at 2-4 months of age. It is
an hereditary skin disorder most often associated with asthma and allergic
rhinitis. Eczema results in thickening, excoriation and often infection of the
skin. In young children the face and neck are mainly affected. The rash is red,
very itchy and weepy on the cheeks. It then spreads to the flexural areas of the
arms and legs. The disease usually undergoes resolution and exacerbation. About
50% of the children with eczema develop allergic rhinitis and between 20%-30%
develop asthma. About 50% of children with eczema undergo complete spontaneous
resolution in time.
Cause
Patients with eczema usually have an allergic tendency which they inherited
from their parents. Ingestion of foods such as cow’s milk, eggs, wheat, soya
protein, peanuts, fish and citrus cause or worsen the condition. Allergy to
house-dust mites can also cause or worsen eczema. Many other factors such as
an abnormal immune response as well as an abnormal neural response involving
the autonomic nervous system are thought to play a role in eczema.
Treatment
Step 1
condition and then to avoid these factors. This often involves
avoiding cow’s milk, eggs, wheat, soya protein, fish and citrus
fruit. This may not be necessary in all patients with eczema but
particularly those who notice a flare-up of their eczema after
ingesting these foods.
Step 2
skin and to relieve the itch. Moisturisers must be used frequently
and regularly.
Step 3
be taken at night since they may cause sedation. Driving and
operating heavy machinery should be avoided if sedation
anti-histamines are taken during the daytime. Keep children’s nails
as short as possible.
Step 4
steroids smut not be used on the face. Once the eczema is
controlled, milder, diluted steroid creams can be used.
Step 5
Preferably wear cotton clothing.
Step 6
or non-enzyme detergents. Bathe in neutral soaps. Avoid perfumed
soaps.
Step 7
treatment or is very weepy, it has probably become infected and
antibiotics may be necessary. Consult your doctor.
Urticaria (Hives)
This is an extremely itchy, distressing condition that
affects at least 20% of us at some time during our live.It comes on suddenly or gradually as red, raised
patches on the body that are extremely itchy.
When deeper layers of the skin are involved, swelling of the face or hand or
feet may occur together.
Urticaria can be acute and last for a short period or it may last for over a
month and is then considered chronic. There are many causes of urticaria, viz.
allergic and non-allergic. In about 80% of people with chronic urticaria, no
cause is found even after exhaustive investigations.
1. Allergic Causes
Those that occur on an allergic basis usually follow ingestion of foods,
food additives and drugs. Ingestion of various foods can cause urticaria but
the common foods implicated are seafood, berries, nuts, eggs and chocolates.
Food preservatives and tartrazine are also causes. Drugs commonly implicated
are antibiotics, aspirin, medicines containing tartrazine, birth control
pills, and medication for colds.
Contact with dogs, cats, plants, insect bites, worm infestation,
infections and blood transfusions can also cause urticaria.
2. Non-Allergic Causes of Physical Urticaria
These occur as a result of various physical agents affecting the skin.
They are as follows:
A. Dermatographism
This is the ability to ‘write on the skin’. If the skin in these
individuals is stroked firmly with a solid object a characteristic wheal and
flare reaction occurs.
B. Cold Urticaria
In this condition urticaria occurs after exposure to cold, cold objects
or water.
C. Heat Urticaria
In this condition urticaria occurs after vigorous exercise or hot baths.
D. Solar Urticaria
Here urticaria occurs after sun exposure.
In a very small percentage of people urticaria is an inherited condition.
It usually begins in childhood and almost always results in angioedema. It
is due to deficiency of a certain factor in the blood complement system.
In a small percentage of individuals, particularly adults, urticaria may
be an outward manifestation of a serious underlying medical condition such
as cancer, endocrine disorders, and the Lupus Syndrome.
3. Treatment
Step 1
angioedema. This may involve dietary restriction, avoiding offending
drugs, avoiding contact with pets to which one may be allergic, as
well as avoiding physical factors which were discussed previously.
Step 2
over-the-counter preparations. The newer anti-histamines are less
sedating and therefore can be used in the daytime as well. Most of
them are long-acting and can be taken once-a-day only.
Step 3
consulted since investigations may be necessary as well as the use
of oral steroids.
Copyright: Allergy Society of South Africa.
Written by Dr
A Manjra
Endorsed by ALLSA.
This information sheet is obtainable
from:
ALLSA P.O. Box 88 Observatory, 7935 Cape Town, R.S.A. |
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