THE course and presentation of an allergic disease is variable and can manifest itself as different symptoms at a later age. While a long list of allergies exists, at the most severe end of the spectrum is anaphylaxis.

It is a life-threatening allergic reaction in which the whole body gets affected, usually within seconds or minutes of exposure to the allergen, a substance that causes allergies in certain people.

Anaphylaxis may pose a threat on the life of the affected individual if immediate medical treatment is not provided. Any type of allergen is capable of causing this condition but food, insect stings and drugs are the most common.

The symptoms of anaphylaxis are any of the following:

• Swelling of the throat and mouth.
• Difficulty in swallowing or speaking.
• Difficulty in breathing due to asthma or throat swelling.
• Hives anywhere on the body, especially large hives.
• Generalised flushing of the skin.
• Abdominal cramps, nausea and vomiting.
• Sudden feeling of weakness (drop in blood pressure).

Most allergies are inherited. Several methods can be used when diagnosing allergies. The first step is to look into a person’s family history.

This quickens the process of identifying the possible causes without wasting time on guessing and going through a host of possibilities.

Therefore, a proper allergy history is essential.

If you suspect that your child has an allergy, here are some useful tips on how to identify the causes:

• Have a record of the history of the symptoms, including whether the symptoms vary according to time of day, season, exposure to house pets and other potential allergens.
• Keep a food diary to record everything your child consumes, or is exposed to, in particular two hours prior to allergy symptoms.
• See a physician, paediatrician, ENT specialist, dermatologist or allergy specialist for guidance.

Prevention begins with you as a parent. Did you know that if one parent has allergies, the child has a 20%-40% risk of developing one?

The risk goes up to 60%-80% if both parents have allergies.

There is no cure for allergies at the moment. However, breastfeeding helps. If your child is not breastfed for 4-6 months, and there is a likelihood that the infant is at high risk of developing allergies, it may be helpful to use a hypoallergenic growing up milk.

There are several tests available for identifying allergies:

Skin prick test: A drop of solution containing a possible allergen is placed on the skin; a series of scratches or needle pricks allows the solution to enter the skin. If the skin develops a red, raised itchy area called a wheal, it usually means that the person is sensitive to that allergen. This is called a positive reaction. If the patient has allergy symptoms, then the patient is allergic to that allergen.

Intradermal test: A small amount of the allergen solution is injected into the skin. An intradermal allergy test may be done when a substance does not cause a reaction in the skin prick test but is still suspected as an allergen for that person. The intradermal test is more sensitive than the skin prick test but is more often positive in people who do not have symptoms to that allergen. This test is done on those with suspected drug allergies.

Contact patch test: This test is for rashes due to allergic contact dermatitis. The allergen solution is placed on a pad which is taped to the skin for 48 hours. This test is used to detect a skin allergy called contact dermatitis.

Specific IgE allergy test: This is a blood test that measures the blood level of IgE, one of the five classes of antibodies. Antibodies are proteins made by the immune system that attack antigens such as bacteria, viruses and allergens.

When the immune system overreacts to foreign substances, even if they are not harmful, an allergic reaction occurs.

What is the key cause for the rise in allergies?

The number of cases of allergic diseases seems to have surged over the last 20 years. With increasing awareness, more people have come forward to seek medical intervention.

One needs to diagnose an allergy, for example, a food allergy, rather than presume that one is allergic to a particular food and avoid it. This is not the correct approach, especially when it involves children. Parents may be wrongly advised to avoid a particular food, thus depriving the child of the necessary nutritional value of that food. Hence, obtaining a firm diagnosis of allergy is imperative.

It is generally accepted that genetics and the environment contribute to the increasing number of allergies. Ongoing research into the prevention of allergy, tends to link these two factors.

It is thought that the way the genes in our body express themselves can be influenced by environmental factors.

This can occur without the change in our genetic profile, that is, the gene sequence remains unaltered but how they present themselves on the “outside” depends on how the “switches” of these genes are being turned off or on.

In short, parents should realise that if they have an allergic disease, then their children are likely to follow suit. Thus these infants are at high risk of a particular allergy and it is recommended that they be exclusively breastfed in the first 4-6 months of their lives.

By Dr AMIR HAMZAH ABDUL LATIFF

This article was first published in www.parenthots.com on 13 July 2011.