allergic rhinitis

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Allergic Rhinitis



Allergic rhinitis, more commonly referred to as hay fever, is an inflammation of the nasal passages caused by allergic reaction to airborne substances.


Allergic rhinitis (AR) is the most common allergic condition and one of the most common of all minor afflictions. It affects between 10-20% of all people in the United States, and is responsible for 2.5% of all doctor visits. Antihistamines and other drugs used to treat allergic rhinitis make up a significant fraction of both prescription and over-the-counter drug sales each year.
There are two types of allergic rhinitis: seasonal and perennial. Seasonal AR occurs in the spring, summer, and early fall, when airborne plant pollens are at their highest levels. In fact, the term hay fever is really a misnomer, since allergy to grass pollen is only one cause of symptoms for most people. Perennial AR occurs all year and is usually caused by home or workplace airborne pollutants. A person can be affected by one or both types. Symptoms of seasonal AR are worst after being outdoors, while symptoms of perennial AR are worst after spending time indoors.
Both types of allergies can develop at any age, although onset in childhood through early adulthood is most common. Although allergy to a particular substance is not inherited, increased allergic sensitivity may "run in the family." While allergies can improve on their own over time, they can also become worse over time.

Causes and symptoms


Allergic rhinitis is a type of immune reaction. Normally, the immune system responds to foreign microorganisms, or particles, like pollen or dust, by producing specific proteins, called antibodies, that are capable of binding to identifying molecules, or antigens, on the foreign particle. This reaction between antibody and antigen sets off a series of reactions designed to protect the body from infection. Sometimes, this same series of reactions is triggered by harmless, everyday substances. This is the condition known as allergy, and the offending substance is called an allergen.
Like all allergic reactions, AR involves a special set of cells in the immune system known as mast cells. Mast cells, found in the lining of the nasal passages and eyelids, display a special type of antibody, called immunoglobulin type E (IgE), on their surface. Inside, mast cells store reactive chemicals in small packets, called granules. When the antibodies encounter allergens, they trigger release of the granules, which spill out their chemicals onto neighboring cells, including blood vessels and nerve cells. One of these chemicals, histamine, binds to the surfaces of these other cells, through special proteins called histamine receptors. Interaction of histamine with receptors on blood vessels causes neighboring cells to become leaky, leading to the fluid collection, swelling, and increased redness characteristic of a runny nose and red, irritated eyes. Histamine also stimulates pain receptors, causing the itchy, scratchy nose, eyes, and throat common in allergic rhinitis.
The number of possible airborne allergens is enormous. Seasonal AR is most commonly caused by grass and tree pollens, since their pollen is produced in large amounts and is dispersed by the wind. Showy flowers, like roses or lilacs, that attract insects produce a sticky pollen that is less likely to become airborne. Different plants release their pollen at different times of the year, so seasonal AR sufferers may be most affected in spring, summer, or fall, depending on which plants provoke a response. The amount of pollen in the air is reflected in the pollen count, often broadcast on the daily news during allergy season. Pollen counts tend to be lower after a good rain that washes the pollen out of the air and higher on warm, dry, windy days.
Virtually any type of tree or grass may cause AR. A few types of weeds that tend to cause the most trouble for people include the following:
  • ragweed
  • sagebrush
  • lamb's-quarters
  • plantain
  • pigweed
  • dock/sorrel
  • tumbleweed

Key terms

Allergen — A substance that provokes an allergic response.
Anaphylaxis — Increased sensitivity caused by previous exposure to an allergen1 that can result in blood vessel dilation (swelling) and smooth muscle contraction. Anaphylaxis can result in sharp blood pressure drops and difficulty breathing.
Antibody — A specific protein produced by the immune system in response to a specific foreign protein or particle called an antigen.
Antigen — A foreign protein to which the body reacts by making antibodies.
Granules — Small packets of reactive chemicals stored within cells.
Histamine — A chemical released by mast cells that activates pain receptors and causes cells to become leaky.
Mast cells — A type of immune system cell that is found in the lining of the nasal passages and eyelids, displays a type of antibody called immunoglobulin type E (IgE) on its cell surface, and participates in the allergic response by releasing histamine from intracellular granules.
Perennial AR is often triggered by house dust, a complicated mixture of airborne particles, many of which are potent allergens. House dust contains some or all of the following:
  • house mite body parts. All houses contain large numbers of microscopic insects called house mites. These harmless insects feed on fibers, fur, and skin shed by the house's larger occupants. Their tiny body parts easily become airborne.
  • animal dander. Animals constantly shed fur, skin flakes, and dried saliva. Carried in the air, or transferred from pet to owner by direct contact, dander can cause allergy in many sensitive people.
  • mold spores. Molds live in damp spots throughout the house, including basements, bathrooms, air ducts, air conditioners, refrigerator drains, damp windowsills, mattresses, and stuffed furniture. Mildew and other molds release airborne spores that circulate throughout the house.
Other potential causes of perennial allergic rhinitis include the following:
  • cigarette smoke
  • perfume
  • cosmetics
  • cleansers
  • copier chemicals
  • industrial chemicals
  • construction material gases


Inflammation of the nose, or rhinitis, is the major symptom of AR. Inflammation causes itching, sneezing, runny nose, redness, and tenderness. Sinus swelling can constrict the eustachian tube that connects the inner ear to the throat, causing a congested feeling and "ear popping." The drip of mucus from the sinuses down the back of the throat, combined with increased sensitivity, can also lead to throat irritation and redness. AR usually also causes redness, itching, and watery eyes. Fatigue and headache are also common.


Diagnosing seasonal AR is usually easy and can often be done without a medical specialist. When symptoms appear in spring or summer and disappear with the onset of cold weather, seasonal AR is almost certainly the culprit. Other causes of rhinitis, including infection, can usually be ruled out by a physical examination and a nasal smear, in which a sample of mucus is taken on a swab for examination.
Allergy tests, including skin testing and provocation testing, can help identify the precise culprit, but may not be done unless a single source is suspected and subsequent avoidance is possible. Skin testing involves placing a small amount of liquid containing a specific allergen on the skin and then either poking, scratching, or injecting it into the skin surface to observe whether redness and swellings occurs. Provocation testing involves challenging an individual with either a small amount of an inhalable or ingestable allergen to see if a response is elicited.
Perennial AR can also usually be diagnosed by careful questioning about the timing of exposure and the onset of symptoms. Specific allergens can be identified through allergy skin testing.


Avoidance of the allergens is the best treatment, but this is often not possible. When it is not possible to avoid one or more allergens, there are two major forms of medical treatment, drugs and immunotherapy.


ANTIHISTAMINES. Antihistamines block the histamine receptors on nasal tissue, decreasing the effect of histamine release by mast cells. They may be used after symptoms appear, though they may be even more effective when used preventively, before symptoms appear. A wide variety of antihistamines are available.
Older antihistamines often produce drowsiness as a major side effect. Such antihistamines include the following:
  • diphenhydramine (Benadryl and generics)
  • chlorpheniramine (Chlor-trimeton and generics)
  • brompheniramine (Dimetane and generics)
  • clemastine (Tavist and generics).
Newer antihistamines that do not cause drowsiness are available by prescription and include the following:
  • astemizole (Hismanal)
  • fexofenadine (Allegra)
  • cetirizine (Zyrtec)
  • azelastin HCl (Astelin).
Loratidine (Claritin) was available only by prescription but was released to over-the-counter status by the FDA.
Hismanal has the potential to cause serious heart arrhythmias when taken with the antibiotic erythromycin, the antifungal drugs ketoconazole and itraconazole, or the antimalarial drug quinine. Taking more than the recommended dose of Hismanal can also cause arrhythimas. Seldane (terfenadine), the original nondrowsy antihistamine, was voluntarily withdrawn from the market by its manufacturers in early 1998 because of this potential and because of the availability of an equally effective, safer alternative drug, fexofenadine.
LEUKOTRIENE RECEPTOR ANTAGONISTS. Leukotriene receptor antagonists (montelukast or Singulair and zafirlukast or Accolate) are a newer class of drugs used daily to help prevent asthma. They've also become approved in the United States to treat allergic rhinitis.
DECONGESTANTS. Decongestants constrict blood vessels to counteract the effects of histamine. This decreases the amount of blood in the nasopahryngeal and sinus mucosa and reduces swelling. Nasal sprays are available that can be applied directly to the nasal lining and oral systemic preparations are available. Decongestants are stimulants and may cause increased heart rate and blood pressure, headaches, isomnia, agitation and difficulty emptying the bladder. Use of topical decongestants for longer than several days can cause loss of effectiveness and rebound congestion, in which nasal passages become more severely swollen than before treatment.
TOPICAL CORTICOSTEROIDS. Topical corticosteroids reduce mucous membrane inflammation and are available by prescription. Allergies tend to become worse as the season progresses because the immune system becomes sensitized to particular antigens and can produce a faster, stronger response. Topical corticosteroids are especially effective at reducing this seasonal sensitization because they work more slowly and last longer than most other medication types. As a result, they are best started before allergy season begins. Side effects are usually mild, but may include headaches, nosebleeds, and unpleasant taste sensations.
MAST CELL STABILIZERS. Cromolyn sodium prevents the release of mast cell granules, thereby preventing release of histamine and the other chemicals contained in them. It acts as a preventive treatment if it is begun several weeks before the onset of the allergy season. It can be used for perennial AR as well.


Immunotherapy, also known as desensitization or allergy shots, alters the balance of antibody types in the body, thereby reducing the ability of IgE to cause allergic reactions. Immunotherapy is preceded by allergy testing to determine the precise allergens responsible. Injections involve very small but gradually increasing amounts of allergen, over several weeks or months, with periodic boosters. Full benefits may take up to several years to achieve and are not seen at all in about one in five patients. Individuals receiving all shots will be monitored closely following each shot because of the small risk of anaphylaxis, a condition that can result in difficulty breathing and a sharp drop in blood pressure.

Alternative treatment

Alternative treatments for AR often focus on modulation of the body's immune response, and frequently center around diet and lifestyle adjustments. Chinese herbal medicine can help rebalance a person's system, as can both acute and constitutional homeopathic treatment. Vitamin C in substantial amounts can help stabilize the mucous membrane response. For symptom relief, western herbal remedies including eyebright (Euphrasia officinalis) and nettle (Urtica dioica) may be helpful. Bee pollen may also be effective in alleviating or eliminating AR symptoms. A 2004 report said that phototherapy (treatment with a combination of ultraviolet and visible light) decreased the symptoms of allergic rhinitis in a majority of patients who did not respond well to traditional drug treatment.


Most people with AR can achieve adequate relief with a combination of preventive strategies and treatment. While allergies may improve over time, they may also get worse or expand to include new allergens. Early treatment can help prevent an increased sensitization to other allergens.


Reducing exposure to pollen may improve symptoms of seasonal AR. Strategies include the following:
  • stay indoors with windows closed during the morning hours, when pollen levels are highest
  • keep car windows up while driving
  • use a surgical face mask when outside
  • avoid uncut fields
  • learn which trees are producing pollen in which seasons, and avoid forests at the height of pollen season
  • wash clothes and hair after being outside
  • clean air conditioner filters in the home regularly
  • use electrostatic filters for central air conditioning
Moving to a region with lower pollen levels is rarely effective, since new allergies often develop
Preventing perennial AR requires identification of the responsible allergens.
Mold spores:
  • keep the house dry through ventilation and use of dehumidifiers
  • use a disinfectant such as dilute bleach to clean surfaces such as bathroom floors and walls
  • have ducts cleaned and disinfected
  • clean and disinfect air conditioners and coolers
  • throw out moldy or mildewed books, shoes, pillows, or furniture
House dust:
  • vacuum frequently, and change the bag regularly. Use a bag with small pores to catch extra-fine particles
  • clean floors and walls with a damp mop
  • install electrostatic filters in heating and cooling ducts, and change all filters regularly
Animal dander:
  • avoid contact if possible
  • wash hands after contact
  • vacuum frequently
  • keep pets out of the bedroom, and off furniture, rugs, and other dander-catching surfaces
  • have your pets bathed and groomed frequently



Finn, Robert. "Rhinoohototherapy Targets Allergic Rhinitis." Skin & Allergy News (July 2004): 62.
"What's New in: Asthma and Allergic Rhinitis." Pulse (September 20, 2004): 50.


inflammation of the mucous membrane of the nose; it may be either mild and chronic or acute. Viruses, bacteria, and allergens are responsible for its varied manifestations. Often a viral rhinitis is complicated by a bacterial infection caused by streptococci, staphylococci, and pneumococci or other bacteria. hay fever, an acute type of allergic rhinitis, is also subject to bacterial complications. Many factors assist the invasion of the mucous membranes by bacteria, including allergens, excessive dryness, exposure to dampness and cold, excessive inhalation of dust, and injury to the nasal cilia due to viral infection.

It usually is not serious, but some forms may be contagious. The mucous membrane of the nose becomes swollen and there is a nasal discharge. Some types are accompanied by fever, muscle aches, and general discomfort with sneezing and running eyes. Breathing through the nose may become difficult or impossible. Often rhinitis is accompanied by inflammation of the throat and sinuses. If bacterial infection develops, the nasal discharge is thick and contains pus.

Acute rhinitis is the medical term for the common cold. Chronic rhinitis may result in permanent thickening of the nasal mucosa. Treatment of rhinitis is aimed at eliminating the primary cause and administration of decongestants to relieve nasal congestion.
acute rhinitis common cold.
allergic rhinitis any allergic reaction of the nasal mucosa, occurring perennially (nonseasonal allergic rhinitis) or seasonally (hay fever).
atrophic rhinitis a chronic form of nonallergic noninfectious rhinitis marked by wasting of the mucous membrane and the glands. It is sometimes the result of trauma, vascular damage by radiation therapy, and environmental irritants, and disease has also been implicated.
rhinitis caseo´sa that with a caseous, gelatinous, and fetid discharge.
fibrinous rhinitis membranous rhinitis.
hypertrophic rhinitis that with thickening and swelling of the mucous membrane.
membranous rhinitis chronic rhinitis with the formation of a false membrane, as in nasal diphtheria; called also fibrinous rhinitis.
nonseasonal allergic rhinitis allergic rhinitis occurring continuously or intermittently all year round, due to exposure to a more or less ever-present allergen, marked by sudden attacks of sneezing, swelling of the nasal mucosa with profuse watery discharge, itching of the eyes, and lacrimation. Called also nonseasonal or perennial hay fever.
seasonal allergic rhinitis hay fever.
vasomotor rhinitis
1. nonallergic rhinitis in which transient changes in vascular tone and permeability (with the same symptoms of allergic rhinitis) are brought on by such stimuli as mild chilling, fatigue, anger, and anxiety.
2. any condition of allergic or nonallergic rhinitis, as opposed to infectious rhinitis.

al·ler·gic rhi·ni·tis

rhinitis associated with hay fever; allergic rhinitis is manifest by sneezing, rhinorrhea, nasal congestion, pruritus of the nose, ears, palate; may also occur concurrently with allergic conjunctivitis.

allergic rhinitis

inflammation of the nasal passages, usually associated with watery nasal discharge and itching of the nose and eyes, caused by a localized sensitivity reaction to an allergen, such as house dust, animal dander, or pollen. The condition may be seasonal, as in hay fever, or perennial, as in allergy to dust or animals. Treatment may include the local, systemic, or topical administration of antihistamines or steroids, avoidance of the antigen, and hyposensitization by injections of diluted antigen in gradually increasing amounts.

allergic rhinitis

An inflammatory response in the nasal passages to allergens, which is the most common form of atopic-allergic disease, affecting 5–20% of the general population. Allergic rhinitis is initiated by exposure of the nasal mucosa to airborne antigens, evoking IgE production; upon repeated re-exposure to the allergen (e.g., ragweed pollen), histamine, leukotrienes C4, D4, E4, B4, PGD2, kinins, kininogen and serotonin are released.

Allergic rhinitis is the most widely used of a plethora of terms referring to the effect of allergens on the upper respiratory tract, in particular the nasopharynx. It is often related to environmental antigens—most commonly pollen—thus being known as seasonal allergic rhinitis (colloquially known as hay fever), and less often to “constant” allergens, in which case it is designated perennial allergic rhinitis.

Clinical findings
Paroxysms of sneezing, nasal congestion, nasal and ocular pruritus, tearing, rhinorrhoea, anosmia, ageusia, postnasal drip (which may cause coughing), partial or total obstruction of airflow, throat clearing, and allergic periorbital hematomas (black eyes).
Skin testing with appropriate inhalant allergens is of greater use than measuring serum IgE.
Avoid allergens; antihistamines (especially H1-receptor antagonists); sympathomimetic amines; anticholinergics; corticosteroids; decongestants; cromolyn sodium; immunotherapy.

Unclear; possibly a hypersensitivity response to allergens in pollen, dander, mites, insects, mould spores, foods; most patients have circulating IgE antibodies that bind to high-affinity receptors on mast cells and basophils, and to low-affinity receptors on other cells, evoking release of inflammatory mediators.

allergic rhinitis

Hay fever Clinical immunology An inflammatory response in the nasal passages to allergens, which is the most common form of atopic–allergic disease, which affects 5-20% of the general population; AR is initiated by exposure of the nasal mucosa to airborne antigens, evoking IgE production; upon repeated re-exposure to the allergen–eg, ragweed pollen, histamine, leukotrienes C4, D4, E4, B4, PGD2, kinins, kininogen, serotonin are released Clinical Paroxysms of sneezing, nasal congestion, nasal and ocular pruritus, tearing, rhinorrhea, anosmia, ageusia, postnasal drip which may cause coughing, partial or total obstruction of airflow, throat clearing, and allergic 'shiners' Diagnosis Skin testing with appropriate inhalant allergens is of greater use than measuring serum IgE Management Avoid allergens, antihistamines, espeially H1 receptor antagonists, sympathomimetic amines, anticholinergic agents, corticosteroids, decongestants, cromolyn sodium, immunotherapy. See H receptors, Hay fever, Immunotherapy, Sensitization.

al·ler·gic rhi·ni·tis

(ă-lĕr'jik rī-nī'tis)
Rhinitis associated with hay fever.

allergic rhinitis

The more respectable term for hay fever (which is not a fever and is not caused by hay). The susceptibility is often inherited (see ATOPY). A specific IMMUNOGLOBULIN (IgE) coats the MAST CELLS in the nose and air passages. When the specific ALLERGEN-grass or tree pollen etc-reaches the mast cells it combines with the IgE and this triggers the release of granules in the mast cells containing HISTAMINE and other highly irritating substances.


John, English physician, 1773-1846.
Bostock catarrh - Synonym(s): allergic rhinitis; hay fever
Bostock disease

al·ler·gic rhi·ni·tis

(ă-lĕr'jik rī-nī'tis) [MIM*607154]
Rhinitis associated with hay fever; manifest by sneezing, rhinorrhea, nasal congestion, pruritus of the nose, ears, palate; may also occur concurrently with allergic conjunctivitis.


pertaining to or caused by allergy.

allergic alveolitis
allergic breakthrough
a theory which attributes temporary increases in clinical severity of atopy to influences, such as concurrent disease or hormonal variations, acting to inhibit the mechanisms which normally regulate production of IgE at low levels following sensitization.
allergic bronchitis
see bronchitis, feline bronchial asthma, pie syndrome.
allergic contact dermatitis
results from percutaneous sensitization to allergens, usually haptens, that form covalent bonds with epidermal proteins, and the development of a delayed (type IV) hypersensitivity. Lesions typically correspond in location to the area of contact between allergen and skin which in animals is often in relatively hairless areas unless the allergen is presented in liquid form.
allergic dermatitis
inflammation of the skin resulting from exposure to antigens to which the animal is hypersensitive. Usually involving immediate (type I) hypersensitivity but also commonly applied to reactions involving delayed (type IV) hypersensitivity. The specific skin reaction, lesions and pattern of disease produced depend on many factors including the type of allergen and immune mechanism, route of exposure and species differences. See also atopy, sweet itch, allergic contact dermatitis (above).
allergic encephalitis
see experimental allergic encephalomyelitis.
equine allergic dermatitis
an intensely itchy dermatitis along the back of horses caused by sensitivity to the bites of the sandfly Culicoides brevitarsus and possibly other insects. Called also sweet itch, Queensland itch.
allergic inhalant dermatitis
see atopy.
allergic reaction
an immune-mediated, adverse clinical response, following the inhalation, ingestion or injection of an antigen by a sensitized animal. Manifestations include urticaria or anaphylaxis.
allergic rhinitis
see enzootic nasal granuloma, summer snuffles.
allergic urticaria

Patient discussion about allergic rhinitis

Q. ALLERGIC RHINITIS what are the causes of?

A. well...that's easy- allergy. some materials, let's say pollens, can travel through the air and then when someone smell them- his body can react like this substance if in fact a threat. cells in the nasal cave release substances that cause rhinitis.

More discussions about allergic rhinitis