FOOD NOT ALWAYS THE CULPRIT
Given that most of us believe that ‘we are what we eat’, it is understandable that many people assume that their itchy skin rashes are related to food allergies. However, Dr Mark Tang, the Senior Consultant Dermatologist at The Skin Specialists & Laser Clinic in Mt Alvernia Medical Centre, sets us straight.
“‘True’ food allergy as the main cause of a skin rash is rare, affecting less than 5% of patients, even in large population studies done both locally and overseas. Food allergies also decrease with age, which is good news for us and our children,” said Dr Tang.
That said, the most common food allergens among Singaporeans include crustacean seafood, such as prawns, eggs and milk. More exotic ones include bird’s nest and even Chinese herbs.
“Compared to our western counterparts, peanut and fish allergies are much less common among Asians,” said Dr Tang.
TELLTALE SYMPTOMS
According to Dr Tang, the most dangerous, but very rare, form of ‘true’ food allergy is similar to the symptoms of a severe drug allergy. This manifests as an almost immediate swelling of the eyes, lips and mouth, with itchy red raised wheals over the body. There may be difficulty breathing and speaking. This is a real emergency and urgent medical attention is required.
Other less severe symptoms include isolated itchy hives and wheals, which look like mosquito bite-like bumps of the skin that last a few minutes to hours. Some patients with sensitive skin or atopic eczema may find that certain foods worsen their eczema, with new or increased inflammation, redness and itchiness.
METHODICAL DIAGNOSIS A MUST
Dr Tang advises that the most accurate way to evaluate food allergy is by careful observation and documentation. There must be clear consistency in the relationship between the food and the onset or worsening of the rashes. A food diary is a useful way to identify or narrow down the list of ‘hidden’ foods.
In the clinic, diagnostic tests include specialised blood tests to identify specific allergy antibodies known as Immunoglobulin E (IgE), and skin prick tests.
DON’T JUMP TO CONCLUSIONS
“True food allergy is rare, and is often confused with other conditions such as food intolerance and food aversion,” said Dr Tang. “While certain foods may aggravate skin conditions such as eczema or urticaria, they may not be the cause. Therefore food elimination diets may not ‘cure’ the condition at hand, and may even be unnecessary.”
So while food may be the usual suspect when rashes break out, it may not be the true culprit. When in doubt, consult a medical professional to obtain the proper testing, evaluation and treatment.
With thanks to our contributor:
Dr Mark Tang
MBBS, MMed (Int Med) MRCP (UK), FRCP (Edin), FAMS (Dermatology)
Senior Consultant Dermatologist
The Skin Specialists & Laser Clinic
Mt Alvernia Medical Centre
