Dr. Alfred Tam
Celeste Child Health Centre,
Canossa Hospital (Caritas)
Specialist in Paediatric Respiratory Medicine
Clinical Associate Professor (Hon.),
The University of Hong Kong
MBBS (HK), FRCP (Edin.,Lond.,Glasg),
FHKCPaed, FHKAM (Paediatrics)
- What are the common clinical allergic symptoms in local infants and young children?
- What are some special cases of childhood allergy with indefinite clinical symptoms?
- Evidence-based scientific approaches for allergy prevention in early stage
- Complementary feeding - A window of opportunity for inducing tolerance
- 4 Practical tips recommended by Dr. Tam for healthcare professionals dealing with allergy issues in infants and young children
What are the common clinical allergic symptoms in local infants and young children?
Of the many common clinical symptoms reported by mothers and/or caregivers concerning allergies, Dr. Tam thinks that rash is the most common complaint. Among the rashes, of more significance is seborrheic dermatitis and eczema. Seborrheic dermatitis is perhaps one of the most reported symptoms in newborns during the first 2 months of life, characterized by skin rash, redness and greasy appearance over the face and scalp. While such condition usually clears up on its own, “seborrheic dermatitis may continue into eczema, and could often be seen in infants of 3 to 6 months old with symptoms extending to all over the body including the creases of elbows and knees,” he explained. While seborrheic dermatitis is often not a manifestation of allergy, eczema is regarded as one of the hallmarks of atopy.
“Dual allergen exposures in terms of diet (especially cow’s milk proteins) and the environment are the major cause of allergic manifestations, especially among formula-fed infants.”
While allergic manifestations may be triggered by direct dietary and environmental exposures, it has also been reported that gastrointestinal symptoms such as bloody stool or loose stool may result from cow’s milk (formula) ingestion. Cow’s milk allergy may also occasionally present in breastfed babies if a small amount of formula is ingested, or the mother ingests a lot of dairy products. As such, Dr. Tam suggested the importance of being investigative in diagnostic methods when trying to identify an underlying problem.
Dr. Tam also shared with us some facts and figures on common allergies in Hong Kong:
|Quick facts – Approximate childhood allergy prevalence in Hong Kong:|
|Allergic rhinitis: 15-30%||Eczema: 10-15%|
|Asthma: 10%||Food allergy: 3-5%|
What are some special cases of childhood allergy with indefinite clinical symptoms?
“Multidisciplinary assessments from constitutional, metabolic, acute infection and gastrointestinal aspects may be required to identify allergy with indefinite clinical symptoms.”
Evidence - based scientific approaches for allergy prevention in early stage
“For healthy infants without a family history of allergy, preventive measures are generally not necessary, due to the lack of clinical effectiveness on allergy prevention in this group.”
Complementary feeding-A window of opportunity for inducing tolerance
While traditionally, many advice have been on food avoidance in managing and preventing food allergies, newer scientific guidelines are suggesting the contrary. In fact, “complementary foods may be introduced after 4 months old, and must be started by 6 months of age,” Dr. Tam said. There is a critical period or window when the immune system learns to cope with food allergens. Delayed introduction of solids may therefore lead to allergy development in the future.
According to the position paper published by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) in 2017, it reinforced complementary foods should not be introduced before 4 months, but also should not be delayed beyond 6 months old. The new advocate suggests allergenic foods such as peanuts and gluten should not require delayed introductions and may be introduced alongside complementary feeding after 4 months2. Dr. Tam mentioned that cultural differences between Asian and Western countries in terms of cooking method and the types of food being introduced during complementary feeding may also be responsible for differences on food allergy prevalence between the East and the West.
“Despite variances in feeding advices over the decades, we can be certain that the best advice would be for mothers to exclusively breastfeed their babies for the first 4 months and beyond, while gradually introducing solid foods within the 4 to 6 months window period,” he advocated.
“Exclusive breastfeeding is the best method for allergy prevention.”
- von Berg A, et al; GINIplus study group. Allergic manifestation 15 years after early intervention with hydrolyzed formulas - the GINI Study. Allergy 2016; 71(2):210-219.
- Fewtrell M, et al. Complementary feeding: A position paper by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) Committee on Nutrition. JPGN 2017; 64:119-132.