Wheal and Flare
Published by ENT Clinics Australia
What is the wheal and flare response?
The wheal and flare response is a descriptor used when talking about a two-stage allergic response seen in Type 1 hypersensitivity. The first stage, called the wheal, is controlled by substances called acute phase mediators. The second stage, called the flare, is controlled by late phase mediators.
What causes the wheal and flare response to start?
The wheal and flare response is triggered by an allergy. When you are exposed to something you are allergic to (in a Type I hypersensitivity reaction, such as allergic rhinitis or asthma), the wheal and flare response begins. Common triggers include:
- House dust mite
- Grasses and pollens
- Fungi
- Cats and dogs
What causes the wheal?
The wheal response is caused by release of histamine from mast cells, which occurs immediately upon contact with the allergen. Histamine causes vasodilation and increased permeability of blood vessels.
Symptoms of the wheal in Allergic Rhinitis
- Itchiness around nose and eyes
- Sneezing
- Runny nose
What causes the flare?
The flare is caused by release of late phase mediators from mast cells, occurring approximately 2 hours after allergen exposure. These include interleukins and leukotrienes.
Symptoms of the flare in Allergic Rhinitis
- Nasal congestion
- Post-nasal drip
- Loss of sense of smell
- Eustachian tube dysfunction
What medications control wheal-related symptoms?
The best medications to control the wheal response in Allergic Rhinitis are antihistamines, available in oral and intranasal forms.
What medications control flare-related symptoms?
The best medications to control flare-related symptoms are intranasal steroids, including fluticasone, mometasone, and ciclesonide.
Where to from here?
If you feel you are suffering from allergic rhinitis which is not well controlled, make an appointment to see either Dr Dan Robinson or Dr Sam Dowthwaite to further discuss treatment options.
Article written by Dr Dan Robinson