What Is Allergy?

Allergy is an immune reaction to a specific substance that’s usually part of the normal environment! The substance “Allergen” enters the body by inhalation, ingestion, touching or injection resulting in the allergy symptoms.

The immune system of the allergic patient produces large amounts of the antibody IgE. Which attacks mast cells in the skin, eye, mouth, stomach, lungs and other places. Breaking mast cells results in release the chemicals that results in allergy symptoms, such as Histamine. This process starts within half an hour of exposure to the allergen and can last for months if not avoided or treated.

The symptoms of allergy depend on the area affected. For example:

  • Allergic rhinitis: nasal itch, runny nose, mucus, sneezing, congestion, cough, headache or bad mouth smell.
  • Allergic conjunctivitis: itch, swelling, redness, watery eye.
  • Allergic Asthma: cough, wheeze, phlegm, shortness of breath, difficulty in exercise, low oxygen.
  • Skin Allergy: itch, skin rash like eczema, smooth skin rash like urticaria, lip swelling, face swelling or other.
  • Gastric allergy: nausea, vomiting, pains, diarrhea or constipation
  • Allergy Diagnosis: The diagnosis of allergy is dependent on the identification of a specific IgE antibody against the item. With the expert allergist opinion, this is the most important step in confirming the diagnosis. Different tests have different advantages and disadvantages regarding accuracy, ease of use, reproducibility and cost. The skin prick test is the most sensitive test. It provides rapid results within 20 minutes. However, sometimes it cannot be done because the patient has severe skin problems, dermatographisim, or because the patient is taking drugs that may affect the test, such as anti-histamines.That’s when the blood IgE test can be useful.
What is Anaphylaxis?

Sometimes allergy affects more than one place at one time! or results in suffocation because of laryngeal edema or fainting because of drop in blood pressure. This is life threatening and can result in death in 1%. This is called Anaphylaxis. Its occurs with food allergy, drug allergy and insect bites.

Is all allergy caused by IgE?

Not all allergy is caused by IgE. But its important to know if its caused by IgE because it indicates a higher risk of multiple & more likely to persist allergies. A higher IgE level predicts a more severe asthma, eczema or food allergy. As well, measuring the level repeatedly can help predict when the allergy will revolve or respond to treatment. Some treatment such as Allergy shots (Allergen Specific Immunotherapy) depend on the presence of specific IgE in treatment of asthma or rhinitis.