Allergy 101

WHAT IS AN ALLERGY?

Our immune system helps us counter invaders such as viruses and bacteria. However, in some people the immune system also reacts to harmless substances such as dust, food and fur. This is called allergy, and symptoms of allergic reaction include rashes, itch and swelling of the eyelids and lips. This could be dangerous if breathlessness and low blood pressure occur. Allergy may be present in the skin (eczema), nose (allergic rhinitis), eyes (allergic conjunctivitis) and airways (asthma).

WHAT CAUSES ALLERGY?

Contrary to common perception, allergy is not caused by exposure to the offending substance (allergen). The cause of allergy is largely genetic. Children with an allergic parent have a 33% chance of developing allergies and this increases to 70% if both parents have allergies.

WHAT ARE SOME COMMON ALLERGENS IN CHILDREN?

Common allergens in children less than three years include house dust mites, cat fur, cow’s milk and hen’s eggs. In older children, house dust mites, cockroaches and cat fur are more common. Food allergy is generally less common in older children.

HOW IS AN ALLERGY DIAGNOSED?

A detailed history of the symptoms, together with a physical examination, is often enough to diagnose if an allergy is present. Allergy testing serves to confirm the diagnosis. However, these tests have to be used in a focused manner and interpreted in the appropriate context, otherwise a person may be inaccurately diagnosed with an allergy that he or she might not have.

HOW DO I TREAT ALLERGY?

Unfortunately, there is still no known cure for allergy. However, there are well-established medications to effectively control symptoms and prevent reactions when exposed to allergens. Avoidance of allergens may be useful, but may not always be possible. Certain allergies like food allergy, eczema and asthma tend to affect younger children and they would outgrow them.

WHAT ARE THE TESTS AVAILABLE?

Skin prick test (SPT) is widely used because it is sensitive in detecting allergies, inexpensive and easy to perform with quick results. Patients will have to discontinue oral antihistamines (cough, runny nose, allergy medicines) at least five days prior to the test. For the SPT, a drop of a suspected allergen is scratched on the surface of the forearm or back skin. Several allergens may be tested at the same time. If there is an allergy, redness and swelling will form at the test spot in 20 to 30 minutes. The results are measured to determine the severity and this would aid the doctor in planning treatment.

There are also other allergy tests in the market, but many of which do not have sufficient scientific evidence to support its use.

Get yourself tested!

Skin prick tests for your little ones are now available at Thomson Paediatric Centre Level 6. For bookings and enquiries, call 6259 7667.