Allergic rhinitis is significantly associated with asthma. Allergic rhinitis occurs in 75–80% of patients with
asthma and conversely, 20–30% of patients with known allergic rhinitis are subsequently found to have asthma.
Family history of atopy is also a known risk factor for seasonal allergic rhinitis.
Many people have both seasonal and perennial allergic rhinitis and are allergic to both indoor and outdoor allergens.
Their symptoms are perennial, with seasonal exacerbations.
Skin prick testing is not essential for diagnosis but may be considered, if the diagnosis is in doubt, if the patient
wishes to determine possible sensitivity to a specific allergen or when expensive avoidance measures or immunotherapy
are being contemplated. A positive reaction to an extract does not necessarily mean that this allergen causes the patients
symptoms, but it provides supportive evidence as part of an overall exposure history.
Towards the end of pollen season, symptoms may worsen. This is known as allergen priming where after repeated exposure
to pollen, the amount of allergen required to induce a response decreases.
Extra for experts
The united airways disease concept
It has been hypothesised that allergic rhinitis and asthma are two manifestations of the same underlying disease and
that an integrated management approach will improve the control of both conditions. Both genetic and environmental factors
are recognised as contributing to the development of an allergic airway syndrome. It has been demonstrated that impaired
nasal function affects the lower airways of patients with asthma. It is thought that a systemic pathway exists between
the upper and lower airways, involving blood and bone marrow.
For more see: Braunstahl G. United airways concept. The Proceedings of the American Thoracic Society 2009;6:652-4.