Allergic rhinitis

Allergic rhinitis is characterized by itching, sneezing, rhinorrhea, nasal congestion, and sometimes conjunctivitis due to exposure to pollen or other allergens seasonally or year-round. Diagnosis is based on history and skin testing. Treatment consists of a combination of antihistamines, decongestants, nasal glucocorticoids, or, in severe, refractory cases, desensitization.

Allergic rhinitis may be seasonal (hay fever) or year-round (perennial rhinitis). At least 25% of long-term (perennial) rhinitis is not allergic. Seasonal rhinitis results from exposure to tree pollens (eg, oak, elm, maple, alder, birch, juniper, olive) in the spring; grass pollens (eg, Bermuda, timothy, sweet vernal, orchard, Johnson grass) and weed pollens (eg, Russian thistle, English plantain) in the summer; and other weed pollens (eg, common ragweed) in the fall. Causes vary by region, and seasonal rhinitis sometimes results from exposure to airborne fungal spores. Long-term (year-round) rhinitis is a consequence of year-round contact with a domestic inhaled allergen (e.g. dust mite, cockroaches, waste products of domestic animals, mold fungi) or persistent reactivity to plant pollen in the corresponding season.

Allergic rhinitis and asthma often coexist; it is unclear whether rhinitis and asthma result from the same allergic process (the "single airway" hypothesis) or whether rhinitis is a trigger for asthma.

Non-allergic forms of long-term (year-round) rhinitis include infectious, vasomotor, atrophic, hormonal, medicinal and gustatory.

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Symptoms of allergic rhinitis

Patients experience itching of the mucous membranes of the nose, eyes, and mouth; sneezing; rhinorrhea; nasal congestion and paranasal sinuses. Obstruction of the paranasal sinuses can cause headaches in the forehead; sinusitis is a common complication. Cough and shortness of breath may also occur, especially if the patient has asthma. The main symptom of perennial rhinitis is chronic nasal congestion, which in children can lead to chronic otitis media; symptoms vary in severity throughout the year. Itching is less pronounced.

Among the objective signs, it is necessary to note edematous, purple-blue nasal turbinates and, in some cases of seasonal rhinitis, injected conjunctiva and eyelid edema.

Diagnosis of allergic rhinitis

Allergic rhinitis is diagnosed based on the history. Diagnostic tests are not necessary unless patients do not improve with empirical treatment, in which case skin testing should be done to detect reactions to seasonal pollens or to dust mites, pet dander, molds, or other antigens (persistent); additional therapy should be prescribed based on these tests. Eosinophilia detected by nasal swab testing with negative skin testing suggests aspirin sensitization or nonallergic rhinitis with eosinophilia (NARES).

In infectious, vasomotor, atrophic, hormonal, medicinal and gustatory rhinitis, the diagnosis is based on the anamnesis and treatment results.

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Treatment of allergic rhinitis

Treatment for seasonal and long-term (year-round) allergic rhinitis is generally similar, although for long-term (year-round) rhinitis it is recommended to try to remove the irritant (such as dust mites or cockroaches).

The most effective first-line agents are oral antihistamines, decongestants, rhinitis drops, and nasal glucocorticoids with or without oral antihistamines. Less effective alternatives include nasal mast cell stabilizers (cromolyn and nedocromil) taken 2 or 4 times daily, the nasal H2 blocker azelastine 2 sprays once daily, and nasal ipratropium 0.03% 2 sprays 4 to 6 hours apart, which helps with rhinorrhea. Often overlooked, intranasal normal saline helps thin thick nasal secretions and moisturizes the nasal mucosa.

Immunotherapy may be more effective in seasonal than in perennial allergic rhinitis; it is needed when symptoms are severe, the allergen cannot be removed, and drug therapy is ineffective. Initial attempts at desensitization should be done immediately after the pollen season ends to prepare for the next season; side effects are increased when immunotherapy is started during the pollen season, since allergic immune responses are already maximally stimulated.

Montelukast improves allergic rhinitis, but its role compared with other treatments is unclear. The role of anti-1gE antibodies in the treatment of allergic rhinitis is being studied, but its use is likely to be limited by the availability of less expensive and effective alternative treatments.

Treatment of NARES is with nasal glucocorticoids. Treatment of aspirin sensitization involves stopping aspirin and, if necessary, desensitization and administration of leukotriene receptor blockers; intranasal glucocorticoids may be used successfully in nasal polyps.