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How do allergies work?

Allergies entering the nose

If you begin experiencing hay fever, food or other allergies for the first time, it’s important to see a doctor before taking further action, As well as providing a diagnosis, a doctor can advise on suitable treatment options.

There are four key components required for the allergic reaction to happen:

  1. Allergen

    Substance causing the allergy.

  2. Immunoglobulin E

    An antibody produced in response to the allergen.

  3. Mast Cells

    Special cells, found in skin and moist linings (nose, eye, mouth) packed with histamine granules. The antibody attached itself to these cells.

  4. Histamine

    Is then released from the mast cells and causes small blood vessels (called capillaries) to widen (dilate). This causes many of the symptoms of allergy as these blood vessels then start to leak their contents into the body tissues causing inflammation of the nose, eyes or airways and results in itchy watery eyes, a runny nose, sneezing and nasal congestion.

Quick Fact: How the allergen enters the body can determine the symptoms, e.g. if the allergen enters via the nose sufferers are likely to sneeze.