Allergy Society of South Africa
For Patients

 

Website Sponsored by:

Skin - Skin Allergy

Allergic Rhinitis Anaphylaxis Asthma
Food Allergy General Topics Insect Allergy
Latex Allergy Oral Allergy Skin Allergy
Allergen Database Occupational Allergy Alternative Medicine


Contents

  • Eczema
  • Urticaria (Hives)
  • Allergenic Causes Urticaria
  • Non-Allergenic Causes 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 The exact causes of eczema are not known but are probably multifactorial. 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

The first step is to identify those factors causing or worsening the 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

The most important treatment for the eczema is to moisturise the skin and to relieve the itch. Moisturisers must be used frequently and regularly.

Step 3

Avoid itching. Anti-histamines can be used. These should preferably 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

Steroid cream should be applied frequently and regularly. Potent steroids smut not be used on the face. Once the eczema is controlled, milder, diluted steroid creams can be used.

Step 5

Do not over-dress children. Avoid woollen and synthetic clothing. Preferably wear cotton clothing.

Step 6

Do not use enzyme powders on bed-linen, clothes or towels. Use soaps or non-enzyme detergents. Bathe in neutral soaps. Avoid perfumed soaps.

Step 7

If the skin undergoes a sudden flare up, is not controlled with 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
	
		
			This involves avoiding factors which trigger attacks of urticaria or 
			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 
	
		
			Many anti-histamines are available for use. Some of these are 
			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
	
		
			If no relief is obtained from Steps 1 and 2, a doctor should be 
			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.		
		
		

		Chacma Baboon
Background: Aardvaark