Seasonal patients suffer from allergies during specific times of the year (spring, summer and early autumn) and perennial allergies occur all year round.
Seasonal allergy symptoms that only appear during certain times of the year are commonly referred to as hayfever, these symptoms are caused by pollen, most commonly grass, weed and tree (e.g. birch) pollens.
Perennial allergy is caused by hypersensitivity to allergens which are present throughout the year, most commonly to pets or dust mites.
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