Medical

Antihistamines:

• oral antihistamines are effective first-line drugs which relieve ocular symptoms, nasal irritation, rhinorrhoea and sneezing, but have limited effect on nasal congestion (1)
  • preferably, non-sedating agents (second-generation) such as loratadine and cetirizine; terfenadine and astemizole have been associated with potentially fatal cardiac arrhythmias
  • there is little evidence to confirm whether, in practice, third-generation antihistamines (e.g., desloratadine or levocetirizine) confer any benefit over second-generation antihistamines. They should be reserved for patients who cannot tolerate or have not responded to other therapies
• nasal antihistamines have a faster onset of action compared to oral agents. They reduce nasal symptoms (itching and sneezing) but not nasal congestion (e.g., azelastine).
• when there is major itching or irritation of the eyes, over-the-counter or prescription antihistamine eye drops may help relieve symptoms. Eye drops using other pharmacologic classes, including NSAIDs and mast cell stabilizers, are also available (2)

Corticosteroids:

• systemic steroids (oral or injected) – used in patients with severe symptoms who are intolerant to or who do not have any benefit from other medications. Should be taken as a single dose in the morning to avoid adrenal suppression.
• treatment methods include:
  • intramuscular depot corticosteroids (equivalent of 100 mg of prednisone)
  • oral corticosteroids (short course)
  • in severe cases of hay fever, systemic steroids, in the form of a course of low dose oral steroid, may be used, e.g., prednisolone up to 20 mg daily for up to 5 days. Until there is clear evidence of its advantages over other allergic rhinitis treatments, including oral prednisolone, the use of depot injections of triamcinolone is no longer acceptable (3)
• Nasal corticosteroids—used as first-line therapy in moderate to severe allergic rhinitis. More effective in relieving nasal symptoms (congestion and sneezing) than oral antihistamines e.g., betamethasone, fluticasone (4)

Inhaled corticosteroids and COVID-19:

• intranasal corticosteroids can be continued in allergic rhinitis
• stopping intranasal corticosteroids is not advised. Immune system suppression has not been proven, and more sneezing after stopping means more spreading of SARS-CoV-2 viral particles (5)

Antihistamine and corticosteroid combination:

• a recent study determined that a combination of intranasal corticosteroids and oral antihistamines has greater efficacy than oral antihistamines alone (6)

Leukotriene receptor antagonists:

• montelukast is effective in treating the overall symptoms of allergic rhinitis
• the combined use of montelukast and an oral antihistamine is superior to either montelukast or an oral antihistamine alone
• generally used as an adjunct with antihistamines, a nasal steroid or both (7)

Mast cell stabilisers:

• intranasal sodium cromoglycate—effective when used just before exposure to an allergen or started 1–2 weeks before pollen season (8)
• intraocular sodium cromoglycate—used as a prophylaxis medication in situations where eye symptoms persist

Anticholinergic agents:

• intranasal ipratropium—used in watery rhinorrhoea (4). Intranasal decongestants (short term) can be used to “relieve congestion” and allow penetration of intranasal corticosteroids

Allergen immunotherapy:

• increasing amounts of allergens are administered subcutaneously to an allergic person to minimise the allergic reaction following exposure to that particular allergen (9)
• allergen immunotherapy has been shown to modify the underlying cause of the disease, with proven long-term benefits
• can be administered sublingually as well
• should be considered in patients:
• with persistent moderate to severe symptoms in spite of treatment
• who need systemic corticosteroids
• are unable to avoid the allergen
• with coexisting diseases like sinusitis and asthma
• inadequate response to nasal corticosteroids
• caution: moderately severe to fatal systemic reactions can occur

Treatment options for allergic rhinitis
Intermittent mild symptoms:

• oral antihistamines (intermittent or regular use)—used as a first-line treatment
• intranasal antihistamines—rapid onset of action

Intermittent moderate to severe symptoms

• oral or intranasal antihistamines (intermittent or regular use)
• intranasal corticosteroids—relieve nasal blockage
• intranasal decongestants—used for a short period

Persistent moderate to severe symptoms

• intranasal corticosteroids—drug of first choice
• Intranasal decongestants—used short-term
• if symptoms persist, increase the corticosteroid dose or change to a different one
• antihistamine—if itching and sneezing present
• intranasal ipratropium—if the major symptom is watery rhinorrhoea
• short course of oral steroids if symptoms not controlled

Notes:

• nasal congestion is relieved with topical antihistamines (e.g., azelastine) or topical nasal steroids (e.g., beclomethasone, budesonide or fluticasone). Fluticasone propionate is as effective as beclomethasone and needs to be applied only once daily
• in general, ocular symptoms can be controlled with oral antihistamines. However, sodium cromoglycate eye drops may be a useful adjunct for allergic conjunctivitis
• other drugs that may be useful on occasions include:
  • antibiotics for infective rhinitis
  • saline irrigation for dryness or crusting, either due to the disease or its treatment

Acupuncture:

• complications of long-term intranasal corticosteroid use include nasal dryness and epistaxis. For this reason, certain patients may wish to pursue non-pharmacologic interventions. If a qualified acupuncture practitioner is available, it is an option to consider for these patients
• acupuncture may modulate the immune system and has been proposed as a useful treatment for patients with allergic rhinitis. The results of clinical studies indicate that acupuncture has comparable effects to medical treatment on patients with moderate to severe allergic rhinitis, and it is safe with no severe adverse effects (10)

Probiotics: an up-and-coming treatment for allergic rhinitis:

• the use of probiotics is a novel treatment approach that is being studied and applied to a number of immune-mediated and allergic diseases
• probiotics may help improve symptoms and quality of life for patients with allergic rhinitis. Numerous studies have shown significant clinical improvement over placebo. Although ideal strains and doses are still being evaluated, probiotics show promise as a new treatment option for allergic rhinitis (11)

References:

1. Kawauchi H, Yanai K, Wang D, et al. Antihistamines for allergic rhinitis treatment from the viewpoint of nonsedative properties. Int J Mol Sci 2019;20(1):213.
2. Bielory L, Katelaris CH, Lightman S, et al. Treating the ocular component of allergic rhinoconjunctivitis and related eye disorders. MedGenMed 2007;9(3):35.
3. Hox V, Lourijsen E, Jordens A, et al. Benefits and harm of systemic steroids for short- and long-term use in rhinitis and rhinosinusitis: an EAACI position paper. Clin Transl Allergy 2020;3(10):1.
4. Clinical knowledge summaries, safe practical clinical answers. Allergic rhinitis.
5. Bousquet J, Akdis CA, Jutel M, et al. Intranasal corticosteroids in allergic rhinitis in COVID-19 infected patients: An ARIA-EAACI statement. Allergy 2020;75(10):2440–2444.
6. Feng S, Fan Y, Liang Z, et al. Concomitant corticosteroid nasal spray plus antihistamine (oral or local spray) for the symptomatic management of allergic rhinitis. Eur Arch Otorhinolaryngol 2016;273(11):3477–3486.
7. Krishnamoorthy M, Noor NM, Lazim NM, et al. Efficacy of montelukast in allergic rhinitis treatment: a systematic review and meta-analysis. Drugs 2020;80(17):1831–1851.
8. https://www.medscape.com/answers/134825-5094/which-medications-in-the-drug-class-mast-cell-stabilizers-are-used-in-the-treatment-of-allergic-rhinitis (accessed 05 December 2021).
9. https://www.worldallergy.org/education-and-programs/education/allergic-disease-resource-center/professionals/allergen-immunotherapy-a-synopsis (accessed 05 December 2021).
10. Bao H, Si D, Gao L, et al. Acupuncture for the treatment of allergic rhinitis: a systematic review protocol. Medicine (Baltimore) 2018;97(51):e13772.
11. Zajac AE, Adams AS, Turner JH. A systematic review and meta-analysis of probiotics for the treatment of allergic rhinitis. Int Forum Allergy Rhinol 2015;5(6):524–532.