Seasonal Allergies Treatment Guideline

Introduction to Treatment Options

The American College of Physicians recommends using second-generation non-sedating antihistamines as first-line therapy for patients with seasonal allergies, with intranasal corticosteroids recommended for moderate-to-severe symptoms or as step-up therapy when antihistamines alone are insufficient, with a strong quality evidence and weak recommendation for combination therapy 1

For moderate-to-severe symptoms, intranasal corticosteroids are recommended as first-line therapy, with dosing for fluticasone propionate nasal spray being 2 sprays (50 mcg each) in each nostril once daily for adults, and 1 spray in each nostril daily for adolescents and children (≥4 years) 1
The Joint Task Force on Practice Parameters found that adding an intranasal antihistamine to an intranasal corticosteroid provides additional benefit for inadequate response to monotherapy, with strong quality evidence and weak recommendation 1
Intranasal corticosteroids are more effective than leukotriene receptor antagonists, such as montelukast, for seasonal allergic rhinitis, with high-quality evidence and strong recommendation 1
Second-generation antihistamines (e.g., fexofenadine, loratadine, desloratadine) are preferred over first-generation antihistamines due to their non-sedating properties and minimal side effects, with recommendations from the American Academy of Allergy, Asthma, and Immunology 2, 1

For mild symptoms, second-generation non-sedating antihistamines are recommended, while for moderate-to-severe symptoms, intranasal corticosteroids are recommended 1
If there is an inadequate response to antihistamine, adding or switching to intranasal corticosteroid is recommended, and if there is an inadequate response to intranasal corticosteroid, considering adding intranasal antihistamine is recommended, with a note that this may cause dysgeusia in 2.1-13.5% of patients 1
For persistent symptoms despite above treatments, considering allergen immunotherapy (subcutaneous or sublingual) is recommended, as the only disease-modifying treatment 1
The American College of Physicians recommends Allegra (fexofenadine) as the best first-line treatment option among the choices provided, due to its effectiveness in treating histamine-mediated symptoms with minimal side effects 1

Monitoring for common side effects of intranasal corticosteroids, such as epistaxis and nasal irritation, and intranasal antihistamines, such as dysgeusia and somnolence, is recommended 1
Cetirizine may cause sedation in up to 13.7% of patients, even at recommended doses, and intranasal azelastine may cause sedation in up to 11.5% of patients at recommended doses 2, 3
First-generation antihistamines (diphenhydramine, chlorpheniramine) should be used with caution due to their significant sedative and anticholinergic effects, and decongestants (pseudoephedrine, phenylephrine) may reduce nasal congestion but can cause side effects such as insomnia, irritability, and palpitations 2

For patients with concurrent asthma, proper treatment of allergic rhinitis may improve asthma control, according to the American Thoracic Society 4
The American College of Physicians recommends against relying on first-generation antihistamines like Benadryl as first-line therapy due to sedation and anticholinergic effects, and against using oral corticosteroids (Medrol) for routine seasonal allergic rhinitis management due to significant side effects with prolonged use 1
The American College of Physicians also recommends against using decongestants alone (Sudafed) as they only address nasal congestion, not the full spectrum of allergic symptoms, and against delaying escalation to intranasal corticosteroids if symptoms are not adequately controlled with antihistamines 1