Treatment of allergic rhinitis has three main components: avoidance of exposure to known allergens, pharmacotherapy, and immunotherapy.
Allergen avoidance
Some forms of allergen avoidance can be effective in management of allergic rhinitis; though proof in randomized trials has been difficult to generate, this is still a standard recommendation for patients. Staying indoors with the windows closed while pollens and molds are in their seasonal and daytime peaks can decrease disease burden. Other measures include regular vacuuming of carpet, removal of pets from home, and frequent washing of bedding. These factors are particularly relevant for the older patient since s/he may spend significantly more time indoors and therefore may be exposed to allergens such as dust mites and indoor molds more than outdoor allergens such as pollens. As such, they may face a perennial allergen challenge which is sometimes more difficult to control. Cost and practicality must govern recommendations in this area for costly and difficult measures (e.g., carpet removal, HEPA filters, etc.) given the lack of evidence for efficacy for these measures.
Pharmacotherapy
Second generation antihistamines are standard in the treatment of mild allergic diseases. These agents are effective in reducing symptoms of nasal and ocular pruritis, rhinorrhea, and sneezing, but do little in managing nasal congestion[
2,
96]. Second generation agents are safe in older rhinitis patients since they do not carry the risk of anticholinergic or alpha-adrenergic activity[
57,
76]. First-generation antihistamines should not be prescribed as they have numerous potential adverse effects on the central nervous system and interactions with other medications, which are more pronounced in the geriatric population[
10,
57,
76]. For example, these medications can affect driving performance more than alcohol, perturb the normal sleep cycle, and markedly affect attention and cognitive performance[
97,
98], all of these factors being germane to the older patient.
Topical antihistamines, such azelastine, are good alternatives to the oral therapy and are approved for seasonal allergic rhinitis in the United States. Studies have proven equal efficacy to ebastine, cetirizine, loratadine, and terfenadine in terms of symptom reduction and may also improve nasal congestion more so than oral antihistamines[
99]. Azelastine has been shown to be well tolerated in geriatric patients[
100]. Typical adverse events include bitter taste, sedation, headache, and application site irritation[
99,
101]. Topical antihistamines have demonstrated greater efficacy when combined with intranasal steroids than either agent alone[
102]. A new formulation of azelastine was developed to reduce the bitter taste associated with the medication. This new product is as effective as the older version with similar frequency and constellation of side effects[
103,
104].
Intranasal steroids have become first-line treatment for moderate to severe allergic rhinitis and effectively treat all symptoms of rhinitis[
105]. A recent randomized controlled trial studied the effects of mometasone furoate nasal spray in patients older than 65 years of age suffering from perennial allergic rhinitis, showing it to be an effective treatment in this cohort[
106]. Intranasal steroids are generally well tolerated by older patients[
10,
107]; however, they can aggravate nasal dryness, epistaxis, and mucosal crusting in geriatric patients[
108]. Therefore, careful instruction in use with patients is critical along with close follow-up to examine the presence of these problems in the nose.
Topical and systemic decongestants are alpha-adrenergic agonists that significantly reduce nasal congestion, however they do not relieve symptoms sneezing, pruritis, and secretions[
109]. Decongestants can be used with antihistamines if a patient presents with multiple rhinitis symptoms including congestion. Oral agents are avoided in those older patients with multiple comorbid conditions such as coronary artery disease, diabetes, hypertension, hyperthyroidism, narrow angle glaucoma, and symptoms of bladder neck obstruction[
96,
110,
111]. Side effects from oral decongestants include palpitations, insomnia, nervousness, and irritability. Some patients may have trouble with urination and a decreased appetite[
2]. The major side effect of topical decongestant overuse is rebound vasodilation and nasal dryness, as well as the potential for rhinitis medicamentosa with prolonged use[
105,
112].
Leukotriene receptor antagonists (e.g. montelukast, zileuton) decrease the inflammatory response in allergic rhinitis and limit symptoms of congestion, sneezing, and rhinorrhea[
113]. These agents are weak as a monotherapy and are commonly used as an adjunct to antihistamine or intranasal steroid treatment[
96,
114]. Long-term data has not been reported to determine safety of leukotriene inhibitors in the older patients, yet these medications seem to be well tolerated in this population[
10,
115]. These agents primarily help with congestion and are particularly useful in asthmatics where they may have the double benefit of improving lower airway disease.
Intranasal cromolyn sodium can be effective in minimizing allergic rhinitis symptoms in refractory patients. This agent inhibits the degranulation of sensitized mast cells thereby preventing the release of mediators of the allergic response and inflammation[
116]. Patients who are given nasal cromolyn sodium must be instructed to use it before an anticipated allergen exposure and to use it on a regular basis during the period of exposure[
2]. Cromolyn may require two to three weeks of use before any benefit is experienced and should be used three to four times per day[
105]. The medication is generally well tolerated and side effects are minimal[
116]. Cromolyn can be good option in older patients that cannot tolerate antihistamines and decongestants, or with use of multiple medications due to its lack of drug interactions [
102,
116].