a woman scratching her neck due to rashes

Sudden Food Sensitivity in Adults

Sudden Food Intolerance

A food allergy is an immune-mediated reaction to some particular foods. For someone with a food allergy, eating or swallowing even a small amount of a particular food can cause skin rash, nausea, vomiting, cramping, and diarrhoea. Because the body is showing a reaction to something that is otherwise harmless, this type of allergic reaction is often called a hypersensitivity reaction. Very rarely, a severe allergic reaction can cause life-threatening symptoms called anaphylaxis or anaphylactic shock.

Although a huge percentage of people assume they have a food allergy, few adults and children, mainly younger than 6 years, have true food allergies. The rest have a food intolerance, a reaction to food that does not involve the immune system.

It is very easy to confuse people's food intolerance with a food allergy because they can show very similar symptoms. However, with food intolerance, a person usually gets only mild symptoms like an upset stomach.

A very common example of food intolerance is lactose intolerance which can cause loose stools, gas, and nausea after eating dairy products such as milk or cheese.

Another example of food intolerance is a reaction to MSG or monosodium glutamate, which is a white-coloured additive used to enhance the food flavour. It is a fermented mixture of glutamic acid, water, and sodium and is mainly used in Asian cooking. 

What Are the Symptoms and Signs of a Food Allergy?

A person with a food allergy can have symptoms within 2 minutes after eating the food, but reactions may take 1-2 hours to appear. 

Symptoms of a more severe reaction to foods or drinks include:

  • Shortness of breath or difficulty breathing
  • Tightness in the chest
  • The feeling of choking or tightness in the throat
  • Rapid or irregular heartbeat
  • Feeling dizzy or light-headed
  • Losing consciousness

A severe allergic reaction can be life-threatening which is referred to as anaphylaxis or anaphylactic shock.

Signs and symptoms of anaphylactic shock are:

Dizziness, lightheadedness, and loss of consciousness due to very low blood pressure, are called "shock."

An anaphylactic reaction can start suddenly, or it may develop gradually with itchiness and swelling of the skin and throat and then reach a severe reaction level within a few hours.

Most people get such a severe reaction immediately after eating the food, but in a few cases, the reaction occurs only after exercising following the intake of the food.

Severe reactions are seen most often with allergies to nuts, fish, and shellfish, although an allergy to any food can cause anaphylaxis.

People with asthma, childhood allergies, eczema, or prior severe food allergies are very much at risk of having an anaphylactic reaction.

MSG reaction can sometimes be mistaken for an allergic reaction. Signs and symptoms of MSG reaction include:

  • Burning sensation at the back of the neck as well as the arms and chest
  • Tingling and numbness in the same areas
  • Headache
  • Nausea
  • Occasionally, difficulty breathing, especially in those with asthma
  • A few people experience seizures, irregular heartbeats, and anaphylaxis after the usage of MSG.

Contrary to popular beliefs, MSG has no connection to Alzheimer's or Huntington's disease, or any other chronic illnesses.

What triggers food intolerance or Allergic Reactions?

An allergic reaction occurs when the immune system of the body overreacts to an allergen, in this case, a food protein.

The white blood cells produce an antibody, called immunoglobulin E or IgE.

When this antibody comes in contact with a particular food protein, it boosts the production and release of certain chemicals called "mediators" like Histamine.

These mediators act on several parts of the body, mainly the skin, throat, airways, intestines, and heart.

Cross-reaction: Generally, people who have allergies react only to certain foods. Occasionally, a person who is allergic to one food may also be allergic to other related foods. This is called cross-reaction. Common examples are:

Allergy to peanuts - Cross-allergies to the soybeans, green beans, and peas

Allergy to wheat - Cross-allergy to rye

Allergy to cow's milk - Cross-allergy to the goat's milk

Allergy to pollen - Cross-allergies to the foods like hazelnuts, green apples, and almonds.

Other allergies: People who have a history of other allergies, such as eczema or asthma, are particularly very much prone to having a reaction to a food. They are also likely to have a more severe reaction.

Natural Home Remedies to Treat an Allergic Reaction to Food

For other mild skin reactions:

  • Take cool showers or apply cool compresses.
  • Wear light clothing.
  • Keep activity level low.
  • To relieve the itching, apply calamine lotion or take OTC antihistamines, such as diphenhydramine (Benadryl) or chlorpheniramine maleate (Chlor-Trimeton).

For all other reactions, especially any severe reactions, self-treatment is not at all recommended. 

Take Away

Food intolerances differ from food allergies. Most do not trigger the immune system, and they usually have less severe symptoms.

However, they can have a worse impact on your health and should be considered seriously.

Many people are intolerant or very sensitive to foods like dairy products, caffeine and gluten.

Although food intolerances are usually less serious than food allergies, they can definitely affect your quality of life.

This is why it’s important to take steps to identify food allergies and intolerances in order to prevent unwanted symptoms and health issues.