Nasal allergies refer to the interaction of allergens with the cells that line the nose.
Allergens that commonly enter through the nose include pollens, dust, dust mites, mold spores, and animal dander. These substances interact with a type of antibody known as immunoglobulin E (IgE) on the mast cells (a kind of immune cell) inside the nose. This causes discharge of histamine. Histamine causes sneezing, nasal congestion, and nasal discharge.
The mast cells also release other substances. These substances pull a group of cells, called eosinophils, into the nasal lining. The eosinophils travel into the lining of the nose over a 6- to 24-hour period. They then release substances that can create additional symptoms hours after the original exposure.
The first reaction is called the "early" reaction. The symptoms occurring hours after the initial exposure make up the "late-phase" reaction. For example, an individual who is sensitive to cats will develop an immediate allergic reaction when exposed to a cat. This initial acute attack may continue as long as the individual is exposed. Once the person leaves the environment, the symptoms subside. Later, the release of eosinophils may bring on another wave of the symptoms.
The symptoms of a nasal allergy are: clear, watery nasal dischargecoughingitching deep within the earitching, watering, and redness of the eyesnasal itchingnasal stuffiness with subsequent difficulty breathingsneezing
Late-phase reactions are very similar. The individual who has chronic allergy exposure may start to see other symptoms, such as: more constant nasal stuffinessreduced sense of smellsinus headaches, usually in the forehead, cheek, and between the eyesa thicker, clear-to-white mucus secretion
An individual with chronic allergies may also start to be affected by nonallergic stimuli. These can include dry air, cold air, smoke, and particles in the air.
The main cause of nasal allergies is an interaction between cells lining the nose and allergens. Common allergens include pollens, dust, dust mites, molds, and animal dander.
Many allergens are present in the air, so it may be very difficult for some people to prevent nasal allergies. If a person's allergies are triggered by cats or specific animals, it is important to keep the animals out of the home.People who suffer from dust or dust mite allergies can benefit from having wood or tile floors. They can use airtight pillow and mattress covers. Persons with severe nasal allergies may consider moving to a drier climate.People with nasal allergies should avoid tobacco smoke.
Antihistamines, such as diphenhydramine or chlorpheniramine, can block the symptoms. Nasal steroid sprays, such as cromolyn, help to stop mast cells from releasing their substances. Nasal steroids stop the mast cell from discharging and thus prevent early symptoms.
Diagnosis of allergies begins with a history and physical exam. The person may report symptoms after a specific exposure, such as being around cats. Sometimes, the individual will have symptoms at a certain time of year, coinciding with the pollination season for a particular plant.
Sometimes, the individual will have symptoms during particular seasons. For those with ongoing symptoms such as nasal stuffiness, other tests can be performed. The healthcare professional may order a test that looks for eosinophils in the nasal mucus. Allergy testing may be done to determine the particular triggers that cause the individual's symptoms.
Most of the long-term effects occur in those who have prolonged or frequent periods of allergic disease. The presence of allergic rhinitis increases the risk of asthma fourfold. People with chronic allergies, such as those who are sensitive to dust, are more likely to develop chronic long-term symptoms.
Individuals who have allergic disease for long periods, such as spring through fall, may also develop long-term symptoms. These long-term symptoms include: chronic coughconstant nasal congestionexcessive, thick nasal mucusfacial painfatigueloss of sense of smellsinus headachessnoring, in persons with chronic nasal congestion
Nasal allergies can predispose an individual to sinus infections and asthma. Lost productivity costing billions of dollars per year occurs because of allergic disease.
The key to allergy treatment is avoiding the allergen. This may be possible for people with pet allergies. It is less practical for those who are sensitive to pollens and molds. Oral antihistamines are used for short-term allergic disease. Common antihistamines include diphenhydramine, loratadine, and fexofenadine. They are very effective in controlling symptoms such as sneezing and nasal discharge.
Antihistamines generally do not reduce nasal stuffiness. For this reason, it is common to add a decongestant, such as pseudoephedrine, to an antihistamine. For severe, acute flare-ups, oral steroids, such as prednisone, are used. Steroids block the allergic response.
Nasal steroid sprays, such as beclomethasone and mometasone, are used for prolonged allergies. These agents have been used for many years, are very safe, and control acute symptoms more effectively than antihistamines. Nasal steroids also block the late-phase reaction.
Air filters and frequent vacuuming are helpful. Salt water nasal sprays and mucus thinners, such as guaifenesin, can thin nasal secretions. Allergy shots can be used in people who have chronic or prolonged periods of allergic disease. The shots, consisting of tiny but gradually increasing doses of the allergen, desensitize the person to the trigger. They may be given to individuals who are having complications, such as asthma or chronic sinusitis.
Many over-the-counter antihistamines cause drowsiness and decreased mental alertness. These side effects are less common with newer prescription antihistamines. These include loratadine and certirizine. Decongestants, such as pseudoephedrine, can cause elevation of blood pressure, fast heart rate, and difficulty sleeping.
Nasal steroids may cause nosebleeds and nasal crusts. Use of oral steroids can be complicated by increased appetite, irritability, sleeplessness, weight gain, and stomach irritation. Chronic steroid usage can cause bone thinning, predisposition to infection, diabetes, and cataracts. Allergy shots may cause a severe allergic reaction or anaphylaxis. They may also bring on an asthma attack.
With appropriate treatment of allergies, symptoms usually improve.
Any new or worsening symptoms should be reported to the healthcare professional.