Childhood Allergies and Urbanization: A Public Health Alarm Bell That Needs to Be Heard Today
August 8, 2025
Childhood Allergies and Urbanization: A Public Health Alarm Bell That Needs to Be Heard Today
Author: Dr. Aisyah binti Rahman
Allergist - Clinical Immunologist
Graduated from International Medical University (IMU), Malaysia
When I was a medical student at International Medical University (IMU) more than a decade ago, childhood allergies were still considered a rare and mostly mild condition. However, now, as a Clinical Allergist - Clinical Immunologist working in Johor Bahru, I have witnessed a dramatic increase in the number of young patients with chronic allergic diseases. More notably, most of the cases come from developed urban areas - where modern life inadvertently brings many stimulating factors and risks that parents do not realize.
This is not just a personal health issue, but has become a public health alarm bell in Malaysia and many Southeast Asian countries.
📈 The numbers speak
A recent report by the Institute for Medical Research (IMR) showed that the proportion of Malaysian children with allergic rhinitis has increased from 10% in 2000 to nearly 30% in 2020. In major cities such as Kuala Lumpur, Johor Bahru and Penang, this figure can be as high as nearly 40%.
Similarly, childhood asthma – once considered an adult disease – is now appearing earlier and earlier. A study by the Asthma Society of Malaysia found that 1 in 5 urban children show signs of periodic airway constriction, especially at night or when the weather changes.
Not only that, the number of infants with eczema, cow's milk protein allergy, food allergies such as eggs, seafood, peanuts, etc. is also increasing rapidly, leading to the risk of chronic atopic dermatitis when they grow up.
⚠️ Worrying situations I have encountered
During the medical examination process, I have encountered situations that made me worry:
A 4-year-old girl had hives every time she went to school. The family thought it was due to insect bites, but when testing for allergens, it was discovered that the child was allergic to house dust mites - a very common factor in carpeted classrooms with closed air conditioners.
A 6-year-old boy was hospitalized many times due to asthma relapse after moving from the countryside to the city to live with his grandparents. The cause did not come from genetics, but rather traffic emissions, fine dust and urban air pollution that strongly affected the child's immune system.
A 2-year-old child was misdiagnosed with contact dermatitis for 6 months, when it was actually eczema related to cow's milk protein allergy - only discovered through IgE testing and skin testing at a specialist clinic.
Such cases are not isolated. They are clear evidence that: if not properly diagnosed and treated promptly, allergies not only cause discomfort but also have long-term effects on children's physical, psychological and learning development.
🌆 Why does urbanization increase the risk of allergies?
Many international studies - including those I have accessed at regional allergy conferences - have shown a direct link between urbanization and increased rates of allergies.
Some of the main causes include:
Air pollution: Vehicle exhaust, fine dust, industrial emissions weaken the respiratory system and trigger allergic reactions.
Lack of exposure to natural microorganisms: Children in urban areas rarely play in dirt, sand or live close to nature, causing the immune system to not be properly “trained”.
Closed living environment and constant air conditioning: Increase humidity, accumulate mold and house dust mites – common allergens.
Industrialized diet: Processed foods, additives and high sugar levels can easily cause immune imbalance.
🩺 The role of specialized diagnosis: More than testing
It is time for us to understand that: allergies should not be treated only according to symptoms.
The use of antihistamines, nasal sprays or corticosteroids should only be a small part of the overall treatment process. The most important thing is to accurately identify the cause, the allergen causing the disease and develop a personalized treatment plan, especially in children – where the body is developing and sensitive.
In specialized facilities, like the one where I work, we apply:
Skin Prick Test - helps to quickly detect 20-40 types of allergens in just 30 minutes.
Specific IgE blood test, evaluates the immune response and sensitivity level of each patient.
Immunological analysis to detect potential disorders.
And most importantly: extensive clinical knowledge, constantly updated, helps to connect test data with actual manifestations.
❤ The relationship between allergies and the cardiovascular system: Cannot be underestimated
Few people know that chronic allergies can affect the cardiovascular system, especially in systemic inflammatory reactions. Children with severe asthma are at higher risk of abnormal blood pressure, prolonged hypoxia, and increased right heart pressure.
In addition, improper use of drugs – such as long-term oral corticosteroids – can also cause high blood pressure, dyslipidemia and affect the retina.