Changes

'''2. Subsequent exposure to the specific allergen (Image 2):'''

'''2. Subsequent exposure to the specific allergen (Image 2):'''

* mast cell degranulation.

* [[Mast Cells - WikiBlood|mast cells]] degranulation.

* basophils with IgE receptors are recruited and also degranulate.

* [[Basophils - WikiBlood|basophils]] with [[Immunoglobulin E - WikiBlood|IgE]] receptors are recruited and also degranulate.

Mast cells secrete mediators:

Mast cells secrete mediators:

* The release of inflammatary cytokines which can cause the dog to become itchy.

* The release of inflammatary [[Cytokines - WikiBlood|cytokines]] which can cause the dog to become itchy.

**Steroid mediators, e.g. prostaglandins and leukotriens

**Steroid mediators, e.g. prostaglandins and leukotriens

1. Chemoattractants (attracts mainly neutrophils but also eosinophils, monocytes and basophils and plasma)

1. Chemoattractants (attracts mainly neutrophils but also [[Eosinophils - WikiBlood|eosinophils]], [[Monocytes - WikiBlood||monocytes]] and [[Basophils - WikiBlood|basophils]] and plasma)

2. Vasoactive and inflammatory peptides (e.g. histamine and serotonin) which causes acute contraction of smooth muscle fibres  

2. Vasoactive and inflammatory peptides (e.g. histamine and serotonin) which causes acute contraction of smooth muscle fibres  

**If the allergen is inhaled (locally) it can lead to bronchoconstriction.

**If the allergen is inhaled (locally) it can lead to bronchoconstriction.

'''3. The late phase response:'''

'''3. The late phase response:'''

* Mediated by eosinophils.

* Mediated by [[Eosinophils - WikiBlood|eosinophils]].

* Takes longer (several hours) as the eosinophils are mobilised from the bone marrow.

* Takes longer (several hours) as the eosinophils are mobilised from the bone marrow.