Allergic rhinitis is seasonal or perennial itching, sneezing, rhinorrhea, nasal congestion, and sometimes conjunctivitis, caused by exposure to pollens or other allergens. Diagnosis is by history and occasionally skin testing. First-line treatment is with a nasal corticosteroid (with or without an oral or a nasal antihistamine) or with an oral antihistamine plus an oral decongestant.
(See also Overview of Allergic and Atopic Disorders.)
Allergic rhinitis may occur seasonally or throughout the year (as a form of perennial rhinitis). Seasonal rhinitis is usually allergic. At least 25% of perennial rhinitis is nonallergic.
Seasonal allergic rhinitis (hay fever) is most often caused by plant allergens, which vary by season and geographic location. Common plant allergens include
Spring: Tree pollens (eg, oak, elm, maple, alder, birch, juniper, olive)
Summer: Grass pollens (eg, Bermuda, timothy, sweet vernal, orchard, Johnson) and weed pollens (eg, Russian thistle, English plantain)
Fall: Other weed pollens (eg, ragweed)
Causes also differ by region, and seasonal allergic rhinitis is occasionally caused by airborne fungal (mold) spores.
Perennial rhinitis is caused by year-round exposure to indoor inhaled allergens (eg, dust mite feces, cockroach components, animal dander) or by strong reactivity to plant pollens in sequential seasons.
Allergic rhinitis and asthma frequently coexist; whether rhinitis and asthma result from the same allergic process (one-airway hypothesis) or rhinitis is a discrete asthma trigger is unclear.
The numerous nonallergic forms of perennial rhinitis
Symptoms and Signs of Allergic Rhinitis
Patients have itching (in the nose, eyes, or mouth), sneezing, rhinorrhea, and nasal and sinus obstruction. Sinus obstruction may cause frontal headaches; sinusitis is a frequent complication. Coughing and wheezing may also occur, especially if asthma is also present.
The most prominent feature of perennial rhinitis is chronic nasal obstruction, which, in children, can lead to chronic otitis media; symptoms vary in severity throughout the year. Itching is less prominent than in seasonal rhinitis. Chronic sinusitis and nasal polyps may develop.
Signs include edematous, bluish-red nasal turbinates and, in some cases of seasonal allergic rhinitis, conjunctival injection and eyelid edema.
If allergic conjunctivitis is present, symptoms include bilateral mild to severe ocular itching, conjunctival hyperemia, photosensitivity, eyelid edema, and a watery or stringy discharge.
Diagnosis of Allergic Rhinitis
Clinical evaluation
Occasionally skin testing, allergen-specific serum IgE tests, or both
Allergic rhinitis can frequently be diagnosed based on history alone. Diagnostic testing is not routinely needed unless patients do not improve when treated empirically; for such patients, skin tests are done to identify a reaction to pollens (seasonal) or to dust mite feces, cockroaches, animal dander, mold, or other antigens (perennial), which can be used to guide additional treatment.
Occasionally, skin test results are equivocal, or testing cannot be done (eg, because patients are taking drugs that interfere with results and cannot safely be withheld); then, an allergen-specific serum IgE test is done.
A nasal smear to detect eosinophils can be done to confirm allergic rhinitis. Although the test is rarely done anymore, it can be a useful alternative to needlesticks in children or used as an additional tool in the evaluation of rhinitis. The sensitivity and specificity of the test is not clear (1
Nonallergic perennial rhinitis is usually also diagnosed based on history. Lack of a clinical response to treatment for assumed allergic rhinitis and negative results on skin tests and/or an allergen-specific serum IgE test also suggest a nonallergic cause; disorders to consider include nasal tumors, enlarged adenoids, hypertrophic nasal turbinates, granulomatosis with polyangiitis, and sarcoidosis.
Diagnosis reference
1. Pal I, Babu AS, Halder I, Kumar S: Nasal smear eosinophils and allergic rhinitis. Ear Nose Throat 96 (10-11):E17–E22, 2017. doi: 10.1177/0145561317096010-1105
Treatment of Allergic Rhinitis
Antihistamines
Decongestants
Nasal corticosteroids
For seasonal or severe refractory rhinitis, sometimes desensitization
Treatment of seasonal and perennial allergic rhinitis is generally the same, although attempts at removal or avoidance of allergens (eg, eliminating dust mites and cockroaches) are recommended for perennial rhinitis. For seasonal or severe refractory rhinitis, desensitization immunotherapy may help.
The most effective first-line drug treatments are
Intranasal Corticosteroids with or without oral or intranasal antihistamines
Intranasal drugs are often preferred to oral drugs because less of the drug is absorbed systemically.
Intranasal saline, often forgotten, helps mobilize thick nasal secretions and hydrate nasal mucous membranes; various saline solution kits and irrigation devices (eg, squeeze bottles, bulb syringes) and kits are available over the counter, or patients can make their own solutions.
Prevention of Allergic Rhinitis
Avoidance of triggers
Sometimes desensitization
Avoidance of triggers
For perennial allergies, triggers should be removed or avoided if possible. Strategies include the following:
Removing items that collect dust, such as knickknacks, magazines, books, and soft toys
Using synthetic fiber pillows and impermeable mattress covers
Frequently washing bed sheets, pillowcases, and blankets in hot water
Frequently cleaning the house, including dusting, vacuuming, and wet-mopping
Removing upholstered furniture and carpets or frequently vacuuming them
Replacing draperies and shades with blinds
Exterminating cockroaches to eliminate exposure
Using dehumidifiers in basements and other poorly aerated, damp rooms
Using high-efficiency particulate air (HEPA) vacuums and filters
Avoiding food triggers
Limiting pets to certain rooms or keeping them out of the house
Adjunctive nonallergenic triggers (eg, cigarette smoke, strong odors, irritating fumes, air pollution, cold temperatures, high humidity) should also be avoided or controlled when possible.
Desensitization
Desensitization immunotherapy may be more effective for seasonal than for perennial allergic rhinitis; it is indicated when
Symptoms are severe.
The allergen cannot be avoided.
Drug treatment is inadequate.
First attempts at desensitization should begin soon after the pollen season ends to prepare for the next season; adverse reactions increase when desensitization is started during the pollen season because the person’s allergic immunity is already maximally stimulated.
Sublingual immunotherapy using 5–grass pollen sublingual tablets (Oralair®—an extract of 5 grass pollens: sweet vernal, orchard, perennial rye, timothy, and Kentucky blue grass) can be used to treat grass pollen-induced allergic rhinitis. An alternative is a sublingual tablet of timothy grass extract (Grastek®). Dosage is
For adults: One 300-IR (index of reactivity) tablet of the 5-grass pollen extract (Oralair®) or one 2800-BAU (bioequivalent allergy unit) tablet of the timothy grass extract (Grastek®) taken once a day
For patients aged 5 to 17 years: One 100-IR tablet of the 5-grass pollen extract on day 1, two 100-IR tablets simultaneously on day 2, then one 300-IR tablet once a day from day 3 onward
For patients aged ≥ 5 years with grass pollen–induced allergic rhinitis: One 2800-BAU tablet of the timothy grass pollen extract taken once a day
The first dose is given in a health care setting and patients should be observed for 30 minutes after administration because anaphylaxis may occur. If the first dose is tolerated, patients can take subsequent doses at home. Treatment is initiated 4 months before the onset of each grass pollen season and maintained throughout the season.
Sublingual immunotherapy using either ragweed pollen or house dust mite allergen extracts can be used to treat allergic rhinitis induced by these allergens.
Key Points
Seasonal rhinitis is usually an allergic reaction to pollens; perennial allergic rhinitis is caused by year-round exposure to indoor inhaled allergens or by strong reactivity to plant pollens in sequential seasons.
Patients with allergic rhinitis may have cough, wheezing, frontal headache, sinusitis, or, particularly in children with perennial rhinitis, otitis media.
Diagnosis of allergic rhinitis is usually based on the history; skin tests and sometimes an allergen-specific serum IgE test are needed only when patients do not respond to empiric treatment.
Try intranasal corticosteroids first because they are the most effective treatment and have few systemic effects.
Other treatments include oral and intranasal antihistamines and decongestants; intranasal mast cell stabilizers are less effective.
Desensitization sublingual immunotherapy is indicated when symptoms are severe, allergens cannot be avoided, or drug treatment is inadequate.
