Allergic rhinitis is the allergy originated (IgE mediated) inflammatory response of the mucosa on the nasal sinuses. It is characterized by nasal itching, sneezing, watery rhinorrhea, nasal obstruction, itching of the pharynx and the external auditory canals, inflammation of the conjunctiva and rarely the loss of sense of smell. Also, some further general symptoms might add to these (headache, tiredness, low fever, reduced concentration ability), too. Severity of symptoms greatly varies from mild to the loss of working ability.

Some patients suffer from the unpleasant symptoms of allergic rhinitis for a few months, others have it during the entire year. Instead of formerly used denominations such as seasonal and perennial rhinitis, now various types of rhinitis are classified on the basis of new categories, which has an obvious advantage that it focuses on the patients’ symptoms, puts more emphasis on duration as opposed to a probable aetiology, and it can be applied in non-allergic rhinitis, either.

Allergic respiratory diseases are multifactorial. Apart from congenital features, environmental and lifestyle-related factors contribute to the development of allergy. There are two phases in both the natural and experimental form induced by nasal allergen provocation. The early phase appears immediately after the allergen provocation, and is mostly featured by sneezing, itching, watery rhinorrhea, while the late phase, normally taking place in several hours and can be felt even in two days, has impeded nasal breathing as its decisive symptom.