What is the difference between food allergy and food intolerance?

How do immediate-onset food allergies and delayed-onset food allergies differ?

Most people are not aware of the existence of both immediate-onset and delayed-onset food allergies. Do they think they are the same? In reality, the methods of dealing with these two types of food allergies are quite different.

For individuals with immediate-onset food allergies, it is necessary to stop consuming the specific food to prevent allergic reactions. On the other hand, those with delayed-onset food allergies often need to adjust their eating behaviours, such as increasing fibre intake, consuming probiotic supplements with live bacteria like yogurt, or using herbal remedies. Within a short period, patients can usually return to normal eating habits, and previously allergic foods may need to be reintroduced gradually to begin with.

Immediate-onset Food Allergies :

Immediate-onset food allergies, which involve a rapid immune response to ingested food, can manifest themselves quickly and sometimes be severe. Common symptoms of food allergies include :

Skin rashes
Facial swelling
Difficulty in breathing
Anaphylaxis
Itching
Rapid and shallow breathing

In severe cases, a severe allergic reaction can lead to shock and even death.

Immediate-onset Food Allergy :

Immediate-onset food allergies occur when symptoms appear rapidly after consuming the allergenic food. This type of allergy is often triggered by immunoglobulin IgE, released when the body encounters foreign substances such as certain proteins found in fish, shellfish, peanuts, tree nuts, eggs, milk, and soy.

Delayed-onset Food Allergies :

Delayed-onset food allergies show symptoms later after ingestion and can cause swelling and abdominal pain. Various causes contribute to delayed-onset allergies, such as :

Enzyme deficiencies
Food poisoning
Irritable bowel syndrome
Food contamination
Stress

People with delayed-onset food allergies, both in Thailand and globally, often react to proteins like gluten from rice products, dairy, and lactose-containing foods.