Usually pollens or fungal spores inhaled from the atmosphere in seasonal allergic rhinitis. Pets or house dust mite which are present all year usually cause persistent allergic rhinitis. Commonly there is a family history of allergies (rhinitis, asthma and eczema).
There is usually a family history of allergy in allergic rhinitis.
Skin prick testing and IgE blood tests (RAST test) are used to identify the allergen causing the rhinitus.