What Is Allergic Rhinitis?
Allergic rhinitis,also known as pollinosis or hay fever, is when the immune system overreacts to allergens in the air.
What Causes Allergic Rhinitis?
Allergic rhinitis is caused due to hypersensitivity to various kinds of allergens such as dust, pollen, pets, etc. This hypersensitivity is mediated by a blood component called Immunoglobulin E. First the body gets sensitized to an allergen and then overreacts to the same allergen when exposed to it again. Eosinophils are said to be the main cell type involved in symptoms of this condition.
What Are The Symptoms Of Allergic Rhinitis?
There are a combination of symptoms such as excessive sneezing, runny nose and nasal block. Other symptoms that may occur in addition are itching of the nose and eyes, redness and watering of the eyes and itching of the ears and throat. These symptoms can occur throughout the year or during a particular season.
What Are The Risk Factors?
Risk factors include family history of allergic rhinitis, lifestyle changes that increase exposure to allergens and dietary modifications.
How Is Allergic Rhinitis Diagnosed?
- By symptoms
- Blood test- Absolute Eosinophil count helps measure the number of eosinophils in blood. Count higher than 440 cells per cubic mm provides additional evidence of allergy
- Nasal smear for eosinophil count to measure the number of eosinophils in nasal discharge
- Skin prick tests for allergy- An allergen is injected into skin and the local response is recorded. There will be a localized redness with swelling if the person is allergic to that allergen
- Tests to measure the level of immunoglobulin E in the blood
- Nasal allergen challenge test – A small quantity of allergen is introduced into nose and the response is measured
What Is The Treatment For Allergic Rhinitis?
Treatment with medicines includes:
- Antihistamines: These rapidly relieve sneezing, itching and runny nose with little/no effect on blockage
- Topical Glucocorticosteroid nasal sprays: This is the most effective treatment for allergic rhinitis. Regular and prolonged treatment is necessary. These nasal steroids reduce inflammation and consequent hyper reactivity, reduce nasal and eye symptoms and improve the sense of smell. Their onset of action is slow, with some effect after 6-12 hours and maximum effect only after a few days
- Decongestants: Nasal use reduces obstruction, but should be used only for a short period (maximum 7 days)
- Immunotherapy: It involves the repeated administration of allergen extract in order to induce a state of tolerance; with a reduction in clinical symptoms and requirements for medications during subsequent natural allergen exposure. It is indicated in those with severe allergic rhinitis who fail to respond to the usual treatment
- Surgery: Surgery is required in some cases of anatomic abnormalities which prevent the nasal sprays from reaching all parts of the nose.