What is Allergic rhinitis?
Allergic rhinitis is inflammation of the mucous membrane lining the nose and throat due to an allergic reaction. Inhaling dust, fumes, pollen or any other airborne substance to which an individual is allergic provokes an exaggerated response from the immune system. These otherwise harmless substances (allergens) trigger the release of histamine and other chemicals, causing inflammation and fluid production in the lining of the nose and air cavities around the nose (sinuses). This results in the characteristic symptoms of allergic rhinitis: runny nose, sneezing, congestion, watering eyes, and itching of the eyes, nose and throat. The most common allergens causing allergic rhinitis include: tree, grass, and weed pollens, molds, animal hair, feathers, skin scales, house dust, and house dust mites.
Seasonal allergic rhinitis occurs in people who are allergic to pollens and molds present during certain seasons of the year. Also referred to as hay fever, seasonal allergic rhinitis is worse during hot, windy weather, when the pollen count is high.
Perennial allergic rhinitis results from the constant presence of allergens such as mold or dust mites. This type of allergic rhinitis occurs throughout the whole year, but the symptoms may be less severe than with seasonal rhinitis.
Occupational allergic rhinitis occurs when an individual is allergic to specific allergens present only in his work place.
Allergic rhinitis is common and affects between ten and twenty percent of Americans. It is more common in people who have other allergies, such as asthma or eczema, and tends to run in families. Although it can occur at any age, allergic rhinitis has its peak occurrence in the years of early adulthood, and affects women more than men.
How is it diagnosed?
When allergic rhinitis is suspected, the first step is usually to perform a physical examination and obtain a complete medical history. Obtaining the patient’s medical history is important because the presence of other allergies, asthma or eczema raises the likelihood of a person having allergic rhinitis. A family history where allergies are common is another factor that predisposes a person towards allergic rhinitis. Typically the family history will show instances of allergic rhinitis, asthma or other airborne allergies.
The physician will ask the patient about the type of symptoms being experienced, as well as the duration of the symptoms. A physician will also take into account the time of year when evaluating a patient. The symptoms of allergic rhinitis are often seasonal, with symptoms appearing more often during the time of year when pollens and molds are most present. While the allergy season can differ by geography, most people experience allergic flare-ups in the spring or summer.
Allergic rhinitis symptoms often mimic those of a cold (non-allergic rhinitis). For this reason, diagnosing allergic rhinitis can be difficult. Generally, allergy symptoms persist for a longer period of time than cold symptoms (more than seven days), and the mucus produced in the nose during a cold is thicker than with rhinitis. Itching of the ears, nose and throat may be associated with allergic rhinitis, though usually not a cold.
The physician will also inquire about the patient's home environment, work environment and hobbies. This will help the physician pinpoint the allergens that are triggering the symptoms.
Different types of rhinitis are triggered by different factors. Before a diagnosis of allergic rhinitis is made, physicians must be sure another type of rhinitis is not to blame. Changes in the weather, hormones in the individual or physical defects in the nasal septum (partition in the nasal cavity) can all cause rhinitis symptoms.
Once other potential causes of symptoms are ruled out, the next step in diagnosing allergic rhinitis is to identify the specific allergen triggering symptoms. The most common method of identifying allergens is skin testing. Trace amounts of a variety of different allergens are introduced to the patient’s skin. For each specific allergen, a different area of skin is used. When an area of skin reacts with a wheal or a raised red bump (skin rashes), the patient is likely allergic to that specific allergen.
Blood tests, such as a radioallergosorbent test (RAST Test), may be performed to measure the amount of IgE produced by a particular allergen. In addition, x-rays or other types of imaging tests may be performed to rule out other causes of rhinitis, such as possible structural abnormalities, or to detect complications caused by rhinitis.
How is hay fever treated?
Treatment of allergic rhinitis begins with the identification of the agent(s) that caused the allergic reaction. Symptom relief and decreasing the number and severity of further episodes is also addressed. Immediate symptom relief can often be obtained by removing the offending allergen from the environment. If this is not possible, symptom relief can usually be obtained with decongestants and antihistamines. While antihistamines reduce the symptoms of itching, runny nose, and nasal congestion, many have the disadvantage of causing drowsiness.
In cases of chronic allergic rhinitis against multiple allergic agents, nasal anti-inflammatories (corticosteroid drugs) have proven successful in decreasing the number and severity of rhinitis episodes. Allergy shots (immunotherapy) can provide long-term symptom relief by desensitizing an individual to a particular allergen. This is accomplished by the injection of gradually increased amounts of the allergen into the skin or subcutaneous over a period of years. The immune system gradually becomes less sensitive to that allergen, reducing allergic symptoms when the substance is encountered in the future.
Periactin (Cyproheptadine), Phenergan (Promethazine), Zyrtec (Cetirizine), Claritin (Loratadine), Atarax (Hydroxyzine), Clarinex (Desloratadine), Flonase (Fluticasone), Medrol (Methylprednisolone), Atrovent (Ipratropium bromide)
What might complicate it?
Uncontrolled, hay fever can seriously impair quality of life. It can interfere with sleep, resulting in daytime sleepiness, and affect the ability to learn and perform tasks. In addition, untreated or improperly treated allergic rhinitis may eventually lead to other complications (pharyngitis, nasopharyngitis (common cold), tonsillitis, laryngitis). These include chronic ear infections (otitis media) and ear dysfunction. Nasal polyps have also been associated with allergic rhinitis, though the connection is unclear. In immunotherapy, there is always the danger of a severe allergic reaction (anaphylactic shock) shortly after an allergy injection is given.
Treatment can effectively reduce most symptoms of allergic rhinitis. Allergy identification through testing, with attempts to avoid allergen exposure, can reduce the number of future occurrences.
Allergic rhinitis often mimics the common cold.
Internist, otolaryngologist, and allergist.
Notify your physician if
- You have severe symptoms of hay fever that are interfering with your normal activities.
- Signs of infection, such as fever, headache, muscle aches, or thick, discolored nasal discharge, appear. A sinus infection may be complicating the allergy.
Last updated 1 July 2015