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Food Allergy Testing with Signs and Symptoms
Food Allergy Testing with Signs and Symptoms

Food Allergy Testing with Signs and Symptoms

Food allergy is the reaction of your immune system to certain foods. Even a small amount of allergy-causing food might lead to signs and symptoms such as hives, digestive problems or swollen airways. There are certain people for whom a food allergy can lead to serious symptoms or life-threatening reaction called anaphylaxis.

Food allergy affects about 6 to 8 percent of children below 3 years of age and almost 3 percent of adults. Although there is no treatment, some children outgrow food allergy. It is quite easy to confuse a food allergy with food intolerance. Food intolerance is a less serious condition.

Food Allergy - Symptoms

In some people, an allergic reaction to specific foods can be uncomfortable but not severe. For others, an allergic food reaction can be life-threatening. An allergic food reaction generally take place from a few minutes to two hours after food has been consumed.

Common signs and symptoms of are:

  • Itching or tingling in the mouth
  • Eczema, hives or itching
  • Swelling of the face, lips, throat, tongue and other body parts
  • Wheezing, trouble breathing or nasal congestion
  • Diarrhea, nausea, abdominal pain or vomiting
  • Dizziness, fainting or lightheadedness


It can lead to a severe allergic reaction known as anaphylaxis. Life-threatening signs and symptoms of this condition are:

  • Tightening and constriction of the airways
  • Sensation of a lump or swollen throat that makes it quite difficult to breathe
  • Rapid pulse
  • Shock with an extreme drop in blood pressure
  • Rapid pulse
  • Lightheadedness, dizziness or loss of consciousness.

Emergency treatment is vital for anaphylaxis. If not treated on time, then anaphylaxis can cause coma or death.

When you need to visit a doctor for Food Allergy Testing in London

When looking for “best food allergy testing in London”, visit a doctor or an allergist in your area if you have had symptoms of food allergy after eating. If possible, see a doctor or visit a best allergy clinic in London when your allergic reaction takes place. This will enable the doctor to make a more informed diagnosis.

You need to seek emergency treatment for symptoms like:

  • Constriction of the airways that make it difficult to breathe
  • A drop in blood pressure
  • Lightheadedness or dizziness
  • Rapid pulse


When you suffer from it, the immune system detects a particular food or substance in food and reacts to that. The immune system produces cells to release an antibody called immunoglobulin E (IgE) to neutralize allergy-causing food or the allergen itself.

The next time you eat even the smallest amount of food, IgE antibodies will signal your immune system to produce a chemical known as histamine and other chemicals, into the bloodstream. These chemicals can lead to allergy symptoms.

For adults, most food allergies are produced by certain proteins in:

  • Shellfish like crab, lobster and shrimp
  • Tree nuts like pecans and walnuts
  • Fish
  • Peanuts

In children, food allergies are commonly triggered by proteins in:

  • Eggs
  • Cow's milk
  • Peanuts
  • Tree nuts
  • Soy
  • Wheat

Pollen-food allergy syndrome

Also called ‘oral allergy syndrome’, pollen-food allergy influence people who suffer from hay fever. For this reason, some vegetables and fruits or spices and nuts can cause an allergic reaction that will cause itching or tinging in the mouth. In extreme cases, the reaction can lead to anaphylaxis or swelling of the throat.

Proteins in certain vegetables, fruits, spices and nuts can cause the reaction because these are quite similar to allergy-causing proteins that are present in some pollen. So cooking certain foods that can lead to pollen-food allergy syndrome, although the symptoms might be less severe.

Food allergy that can be exercise induced

Eating certain kind of foods might be the reason some people suffer from lightheadedness and itchiness after they do their exercises. Extreme cases might lead to anaphylaxis or hives. If you do not eat for a few hours before exercises and avoid certain foods, this might help prevent this problem.

Food intolerance and other reactions

Food intolerance or a reaction from other substances might have similar signs and symptoms as food allergy. This could be cramping, nausea, diarrhea and vomiting. Based on the kind of food intolerance it may help to eat smaller amounts of the problem food that may not cause a reaction.

One of the more difficult aspects of diagnosing food intolerance is that certain people can be quite sensitive to an ingredient that has been used in preparing food.

Common symptoms:

  • Deficiency of digesting enzyme– You might not have a sufficient number of certain enzymes necessary for digesting certain foods. This can lessen your ability to digest lactose which is sugar that occurs in milk-based products. Lactose intolerance might be the reason for cramping, diarrhea, bloating and excess gas.
  • Food poisoning – Food poisoning can sometimes cause an allergic reaction. The bacteria present in spoiled tuna and other fish can form a toxin that can lead to harmful reactions.
  • Sensitivity to certain food additives – Some people can experience digestive reactions and other symptoms after eating certain food additives.
  • Histamine toxicity – Certain fish, such as mackerel or tuna that have not been refrigerated properly can cause greater levels of histamine. This might trigger some symptoms which are quite similar to food allergy. This is called scombroid poisoning or histamine toxicity.
  • Celiac disease – Though celiac disease is often referred to as gluten allergy, it does not lead to anaphylaxis. Just like food allergy, it involves a response from your immune system however, it is a reaction that seems to be more complicated than a food allergy. This severe digestive condition can be activated by eating gluten, which is a protein found in cookies, pasta, bread and other foods that contain barley, rye or wheat.

If you are suffering from celiac disease and eat certain foods that have gluten, then an immune reaction might take place that can lead to some damage to the surface of the small intestine. This might be the reason for an inability to absorb certain nutrients.

Risk factors with food allergy

  • Family history– You are at greater risk of food allergies if asthma, allergies, eczema or hives are common in your family.
  • Other kinds of allergies – When you are allergic to a specific food, then you might be at greater risk of being allergic to another. If you have other kinds of allergic reactions like eczema or hay fever, then your risk of getting a food allergy seem to be greater.
  • Age factor – Some food allergies are common in children, particularly toddlers and infants. When they grow up, the digestive system matures and allergies can become less.
  • Children who outgrow allergies from milk, wheat, soy and eggs may overcome serious allergies to shellfish and nuts too.
  • Asthma – Asthma and food allergy usually take place together. If someone has both, it will probably be severe.

Some factors that can increase the chances of an anaphylactic reaction:

  • A past record of asthma
  • Being a teenager or young child
  • delay in the use of epinephrine for treating the symptoms of food allergy.


  • Anaphylaxis – This is an allergic reaction that can be life threatening.
  • Atopic dermatitis (eczema) – Food allergy might lead to a skin reaction like eczema.


The introduction of peanut products early is related to lower risk of peanut allergy. Before you introduce allergenic foods, it is advisable to talk to the doctor about this.

If the allergy has already occurred, then the best way to avoid an allergic reaction is to know the foods responsible and avoid them.

If you have a food allergy, then these steps can help to overcome the problem:

  • Know what you eat and drink – You should read food labels carefully and know what you eat and drink in order to avoid any kind of food allergies.
  • If you have had a severe reaction – Wear a medical alert bracelet or necklace that let others to know that you are suffering from a food allergy.
  • Consult with a doctor about emergency epinephrine – If you need to carry an epinephrine autoinjector (Adrenaclick, EpiPen), make sure that you always have it with you
  • Be careful in restaurants- You need to inform the chef you cannot eat certain foods due to Make sure the meal you have ordered do not contain them. Also, food should not be placed on open surfaces or in pans that contained any kind of food you might be allergic to. The staff members will be more than happy to help you once they understand your request.
  • Plan snacks and meals before leaving home – You can carry a cooler with allergen-free foods while traveling or attending an event. These precautions can help you to stay protected.
  • Inform everyone about your food allergy – You should inform everyone that you are allergic to specific food items.
  • Explain the symptoms of a food allergy – Explain the symptoms of an allergic reaction to everyone so they know what to do if you have one.
  • Wear a medical alert necklace or bracelet – This will list the signs and symptoms of food allergy and describe the first aid you will need during an emergency.

Allergy Assessment

The treatment for food allergy starts with a complete medical record. Your allergist will ask about:

  • The symptoms you may have after eating certain foods
  • The time lapse after eating some foods when the symptoms occurred
  • The amount of food you had eaten
  • The number of times you had a reaction
  • Any other foods that caused a reaction.
  • If it occurs every time you eat the same food
  • The kind of medical treatment you have had

How special diets can detect the exact problem

Your allergist will assess the kinds of foods that can cause allergies with a special diet. You might be asked to follow a daily food diary which includes all the food you eat and medication you take, with any symptoms.

If one or two foods cause certain allergies, then you can avoid them. Make sure you don’t eat suspect food at all for one to two weeks. If the allergic symptoms decrease during that time period and flare up again when you eat the same food, then it is quite possible that the food has caused your allergy.

The foods you should avoid and the foods you can eat must be decided by your allergist..

At our private clinic, your allergist will confirm the results of the diet tests with the help of a challenge test. Thus, food allergy testing in London is an important step in diagnosing certain food allergies and safe.