ALLERGIES

PART 1. 
UNDERSTANDING ALLERGIC RHINITIS IN CHILDREN

Runny noses and constant sniffles are a common recurrence among adults and children alike. This phenomenon is inevitably labeled as a 'sinus problem' and often this guess is confirmed after checking with their respective doctors. However, it is really easy for many of my patients to confuse infections; both viral and bacterial, with actual allergies, subsequently leading to a less effective treatment option. For your reading pleasure, I will now explain the truth on alergies in this TWO-PART series of commonly asked questions.

WHAT IS AN ALLERGY?

An allergy occurs when the body's immune system, or the intrinsic defence system, reacts against substances or antigens to many people. These can be separated into two categories: harmful antigens and harmless antigens (allergen).

Viruses and bacteria fall under the HARMFUL category while although dust-mites, cat and dog fur and plant pollens may seem like the enemy, they are indeed harmless.

In simplified medical terms, when in contact with an allergen, your child's immune system celss would release antibodies, specifically immunoglobulin E (lgE). These antibodies bind to the allergen molecules, which eventually leads to the release of the chemical histamine. This chemical is known to cause the symptoms associated with allergy such as the common sneeze and sniffle.

Allergies are commonly suffered through the generations, as there is a genetic or hereditary basis that governs why the immune system reacts against allergens.

WHAT, THEN, IS ALLERGIC RHINITIS?

It is the condition where an irritation or allergy happens in the 'carpet lining' or mucosa, of the nasal cavity and paranasal sinuses. The sinuses are eight hollow cavities within the facial bones and each has a connecting doorway into the nasal cavity.

Allergies may also occurs in the lungs, skin and eyes, known respectively as asthma, eczema and allergic conjunctivitis. A child may be susceptible to one or more of the above types of allergies.

When a particular allergen is inhaled into the nose, it comes into contact with lgE that is specific for it. Histamine release leads to swelling of the mucosa and copious mucus production, causing typical sysmptoms of nose block, sneezing, itch and runny nose.

Naturally, there is avariation in severity and frequency amongs a range of patients. Some may only have blocked noses, some only sneezing and itching, but others may be faced with the full hand of symptoms.

AT WHAT AGE DOES ALLERGIC RHINITIS START?

It is believed that allergic rhinitis starts at the tender age of four, in contrast to the other allergic problems of asthma and eczema that tend to begin in infancy. However, runny and blocked noses are very common in children below four years of age. making it hard not to believe that in fact allergic rhinitis starts earlier than this in some children.

WHAT ARE THE COMMON FACTORS CONTRIBUTING TO ALLERGIC RHINITIS?

The fundamental causes vary from country to country, depending on climate and degree of urbanisation, but only inhaled allergens directly cause allergy in the nose.

Examples of allergens for tropical climates like Malaysia include dust-mite excretions, fungal material and dog or cat dander. Even cockroaches can be a threat to your child's environment. In temperate climates with the four seasons, there are also plant pollens of tree, flower and grass varieties that contribute to this.

DOES WEATHER AND AIR-CONDITIONING MAKE ALLERGIC RHINITIS WORSE?

Parents commonly report that their child's sneezing and runny-nose worsens when spending a day out under the sun or when cooped within an air-conditioned room. They are half right.

Changes in humidity, temperature and certain air pollutants have an independent irritant effect on the nasal mucosa. This irritation makes the mucosa swell up, making the symptoms of allergic rhinitis appear to be worse. This is in fact a separate reaction not to be confused with allergic rhinitis.

Air pollutants may be divided into indoor and outdoor categories. An example of an outdoor air pollutant is diesel fumes while indoor pollutants include household products, pesticide and even tobacco smoke.

WHAT ABOUT FOODS THAT WE TAKE?

Food subtances may cause oral and systemic (asthma and eczema) allergic symptoms. It is said that food substances only rarely directly make allergic rhinitis worse.

Once again, it is inhaled substances that serve as allergens for allergic rhinitis. However, certain foods may modify the immune system, so that it becomes more reactive, thereby also making allergic responses more intense. This is an indirect way, in contrast to the direct allergen way.

HOW ABOUT SWIMMING?

Most swimming pools are chlorinated and it is only this chemical that would contribute to an allergic while swimming, if at all. Chlorine-related gas sits just above the surface of the water. This gas serves as an irritant, just as the weather and air-conditioning would. I truly hope you would understand that your child's allergic rhinitis is actually not make worse. What he/she might experience is a temporary irritation due to the chlorine.

Swimming is an excellent form of sport and excercise. I think a child should not be deprived of the opportunity to do so.

Continue reading on Part 2 which will be posted soon.