IN CASE YOU MISSED IT

Allergic rhinitis on the rise among children

This story was first published in The Straits Times on April 11, 2013

For Lee Yang Fu, an attack of the sneezes would be a warning that something worse than a runny nose was about to occur.

Almost always, it meant he would also get an asthmatic attack and have to be hospitalised.

He was in and out of hospital so much that he missed six months of his first year of kindergarten and had to repeat that academic year. Things got slightly better in primary school. Yang Fu, now 16, said he was able to go to school 75 per cent of the time.

The problem was that the antihistamines - medication to relieve inflammation - he had to take for the runny nose made him drowsy.

It made his ability to concentrate so poor that he failed all his subjects from Primary 1 to 4.

But gradually, with the help of a steroid nasal spray and a procedure to cut away the excess swollen tissue in his nasal passages, he slowly got better.

Now the Secondary 3 student attends school 90 per cent of the time and has an asthmatic attack only once or twice a year.

Yang Fu's experience may not be that unusual in time to come.

More children here, as well as those in developed countries elsewhere, are developing allergic rhinitis.

This happens when the body's immune system becomes sensitised to certain substances, such as the house dust mite, and gives rise to symptoms such as sneezing, blocked nose, excessive nasal discharge or itching.

It is different from infective rhinitis, or the common cold, which ceases once the infection runs its course.

The International Study of Asthma and Allergies in Childhood (Issac) questionnaire surveys found that the cases of allergic rhinitis in six to seven-year-olds in Singapore rose from 6.3 per cent in 1994, to 8.3 per cent in 2001 and 8.7 per cent in 2003, said Associate ProfessorAnne Goh, head and senior consultant of allergy service at the department of paediatrics at KK Women's and Children's Hospital (KKH).

Thirty-seven countries were covered in this study and most of them - 67 per cent - showed an increase in the prevalence of allergic rhinitis.

The problem was significant enough for the Ministry of Health to draw up its first clinical guidelines on the management of allergic rhinitis in 2010.

THE ALLERGY ONSLAUGHT

In general, the incidence of all forms of allergies has been rising. For instance, the Issac noted that the cases of eczema in six to seven year olds in Singapore rose from 2.8 per cent to 8.9 per cent from 1994 to 2001.

The number of asthma cases had been rising and may have reached its peak at around 20 per cent, said DrLynette Shek, the head and senior consultant at the division of paediatric allergy, immunology & rheumatology at the National University Hospital.

Several reasons for the rise of allergies have been proposed, she said.

One popular hypothesis is that with the general decrease in the number of infections over the years, children today are underexposed to bugs and mites, so their immune systems are more sensitive and tend to overreact.

The overuse of antibiotics has also been blamed for the rise of allergies.

Dr Shek said: "Antibiotics wipe out both good and bad bacteria in the body. But children need good bacteria for a healthy immune system. Without a healthy immune system, their risk of allergic reactions is increased."

Another possible reason for the rise in allergies, she said, is the increase in the amount of environmental pollutants, such as cigarette smoke, which irritates the lining of the airways, including that of the nose (leading to allergic rhinitis) and lungs (leading to asthma).

KIDS ARE VULNERABLE

While most of the cases of allergic rhinitis here are mild, about 10 to 20 per cent of the cases in children are moderate to severe and can affect a child's quality of life, said Prof Goh.

She said: "The symptoms can affect the child's quality of sleep and the ability to perform well the next day. It can also affect the child's ability to exercise."

It can lead to dry mouth and snoring, if the child is breathing through the mouth due to a blocked nose, and sinusitis, which is the inflammation of the sinuses (nasal cavities around the nose).

Dr Liew Woei Kang, a consultant paediatric allergist and immunologist at SBCC Baby & Child Clinic at Gleneagles Medical Centre, who is also president of the Asthma and Allergy Association in Singapore, said children tend to have more severe symptoms as their nasal cavities are narrower and get obstructed more easily.

Children with allergic rhinitis are more likely to suffer from asthma-related events and require hospital admissions, added Dr Chiang Wen Chin, of Chiang Children's Allergic and Asthma Clinic at Mount Elizabeth Medical Centre and a visiting consultant and adjunct associate professor at KKH.

A study she authored, which was published in the Pediatric Pulmonology journal last year, found that allergic rhinitis accounts for as high as two-thirds of all childhood chronic rhinitis, which can also be caused by infections. Environmental allergens include dust mites, cockroaches, and cat or dog dander.

The study surveyed 6,600 children aged six months to 19 years seen at KKH from March 2001 to March 2009.

CONFUSION AMONG PARENTS

Although the triggers and treatment of allergic rhinitis are well documented, there is still confusion among parents about these, said doctors.

For instance, some parents believe food such as dairy products and eggs can trigger allergic rhinitis, but there is little evidence for this, said Dr Shek.

Instead, avoiding such nutrient-rich food may be detrimental to a growing child, she said.

Also, parents are reluctant to have their children use steroids even though one of the most effective types of medication for allergic rhinitis is a nasal steroid spray.

Dr Shek said the amount of steroids in the nasal spray is so small it is safe to use.

Parents can look for answers to their queries in a patient's guide published alongside the clinical practice guidelines, which are available on the Ministry of Health website.

Dr Liew said many parents tend to accept their child's allergic rhinitis symptoms as a fact of life because "everyone at home sneezes in the morning anyway".

But there is a difference between the common cold, an acute infective rhinitis which lasts only for a while, and allergic rhinitis, which children generally do not outgrow.

The latter can be controlled through medication and avoiding allergens such as house dust mites.

Dr Liew said house dust mites and dust are not the same thing.

He said: "Physical dust is a pollutant from construction sites, vehicle exhaust and industrial gases. House dust mites are microscopic insects which are common in households."

Some useful steps parents can take to avoid house dust mites are to keep soft toys away from beds and to wash bedsheets and pillowcases in hot water.

Other helpful measures include using house dust mite covers and vacuum cleaners fitted with a high efficiency particulate filter, which can retain microscopic allergen particles, said Dr Liew.

leawee@sph.com.sg

This story was first published in The Straits Times on April 11, 2013

To subscribe to The Straits Times, please go to http://www.sphsubscription.com.sg/eshop/