Medical Centric

FOOD ALLERGY

Men's Health, Women's Health / By

FOOD ALLERGY

Food allergy is an abnormal immune system reaction to food.

  • Even exposure to very small amounts of allergy-causing food can trigger signs and symptoms associated with the condition.
  • Food that causes allergic reactions are called allergens
  • Sometimes allergy symptoms are mild. Other times they are severe. All allergic symptoms should be taken seriously.
  • Both mild and severe symptoms can lead to a serious allergic reaction referred to as anaphylaxis. This reaction usually involves more than one part of the body, can impair breathing, cause a dramatic drop in blood pressure, and affect heart rate
  • To provide the right chance for improvement and prevent serious, potentially life-threatening complications, anaphylaxis must be treated right away
  • The Centers for Disease Control and Prevention estimates that food allergies affect 4%-6% of children and 4% of adults.
  • There are two categories of food allergy: IgE mediated or non-IgE mediated.
  • IgE mediated is the most common type. In this type, the immunoglobin E (IgE) antibody is released by your immune system to fight the threat.
  • In the non-IgE mediated type, IgE antibodies are not released and other parts of the immune system are used to fight the perceived threat.

CAUSES

In food allergies, the immune system mistakenly identifies a specific protein in food as a pathogen, harmful, or as something that may cause disease. To respond to this, the immune system produces antibodies to attack this protein.

When even the smallest amount of that food is eaten again, the antibodies are ready and signal the immune system to release a chemical known as histamine, as well as other chemicals, into the bloodstream. Histamine and these other chemicals cause the symptoms of food allergy.

The most common food allergies which account for about 90% of all food allergies, often referred to as ‘the big eight’ are:

  • Milk
  • Eggs
  • Peanuts (groundnuts)
  • Tree nuts including walnuts, almonds, Brazil nuts, cashews
  • Seafood
  • Shellfish including shrimps, mussels, and crab
  • Soy
  • Wheat

Certain seeds including mustard seed and sesame seeds are also common food allergies

Other foods containing allergenic proteins include fruits, vegetables, maize, and spices.

Risk factors include:

  • Family history
  • Age
  • Other allergies. Being allergic to one food may increase your chance of becoming allergic to another.
  • Asthma

SYMPTOMS

  • Hives
  • Dizziness
  • Abdominal pain
  • Tingling or itching in the mouth
  • Swelling of the lips, face, tongue, and throat or other parts of the body
  • Nasal congestion
  • Nausea
  • Diarrhea

Anaphylaxis

  • Rapid pulse
  • Tightening of the airway
  • Shock with a severe drop in blood pressure
  • Swollen throat
  • Loss of consciousness

DIAGNOSIS AND TREATMENT

Before making a diagnosis, the doctor will consider a number of factors including:

  • Your symptoms
  • A family history of allergies
  • A physical examination to identify or exclude other medical problems
  • A skin prick test to determine reaction to a particular food
  • A blood test to measure your immune system’s response to particular foods by measuring the allergy-related antibody known as IgE
  • Elimination diet. You may be asked to eliminate suspected foods for 4-6 weeks to see if symptoms will clear up.
  • Oral food challenge. During this test, you will be given a small but increasing amount of food suspected of causing your symptoms. You will then be watched for signs and symptoms
TREATMENT

The only and best way to avoid an allergic reaction is to avoid the foods that cause symptoms.

For minor cases, over-the-counter or prescribed antihistamines may help.

For severe cases, an emergency injection of epinephrine may be required. Epinephrine keeps blood pressure up by constricting blood vessels and easing the airways.