Management Allergen avoidance Aeroallergens THE role of aeroallergen avoidance in the management of allergic rhinitis is controversial. This controversy largely exists because as a strategy, avoidance of offending allergens makes perfect common and theoretical sense, but it is not supported by evidence from several well-designed randomised control trials.
A Cochrane Review and the ARIA 2008 Update concluded that while physical and chemical methods of aeroallergen avoidance and reduction had been successfully demonstrated to reduce measurable levels of allergens, this effect did not correlate with clinical benefit. 14, 8 Multifaceted avoidance measures may be of benefit to a small subset of patients.
Some practical techniques that may be helpful in reducing levels of aeroallergens are detailed in box 2. These interventions can be costly and may be of limited clinical benefit, so they should be recommended with caution and consideration of the patient’ s economic means.
Pet allergens Counselling a patient to remove a beloved pet from the home is a challenging and perhaps unwarranted task. Patients who are allergic to furred pets may benefit from such measures, however, they may encounter allergens on public transport, schools, workplaces and other public places.
The only study to have demonstrated clinical benefit in pet allergen-control measures compared extensive measures( washing all floors, removing carpet from bedrooms, applying tannic acid, washing bedding, replacing doonas and pillows, using impermeable covers and washing the cat every two weeks) with an unchanged environment. These onerous measures resulted in a fall of detectable cat allergen to 6.8 % of baseline, and a significant improvement in nasal airflow and symptoms. 15
Pharmacotherapy A broad summary guideline for the pharmacotherapy of allergic rhinitis adapted from the ARIA 2008 Update and the 2017 eTherapeutic Guidelines is presented in table 5. 8,
16
This guideline should be interpreted in the context of a patient’ s symptoms, the frequency of symptoms and the patient’ s likely compliance with therapy. A list of common agents in each category in use in Australia is presented in table 6. It is important to note that some of these agents are prohibited by national and international sport anti-doping agencies.
Immunotherapy Given as subcutaneous immunotherapy or as sublingual immunotherapy in increasing doses, allergen immunotherapy aims to‘ switch off’ the immune response to the offending allergen( s). The allergen extracts used in these treatments are highly potent.
An immunotherapy protocol is initiated on a patient-by-patient
|
Table 5. Pharmacotherapy in allergic rhinitis Intermittent allergic rhinitis Mild
Moderate-severe
Oral H1-antihistamine OR Intranasal antihistamine OR Oral decongestant( except in children) OR Intranasal decongestant( see box 1, Rhinitis medicamentosa)
Review in 2-4 weeks Persistent allergic rhinitis Mild
Oral H1-antihistamine OR Intranasal antihistamine AND / OR ONE OF Intranasal corticosteroid( combination nasal sprays are available) OR Leukotriene receptor antagonist
Review in 2-4 weeks to assess resolution of symptoms. If no improvement, add intranasal corticosteroids if not already started, otherwise add another of the above agents. If no improvement after subsequent review or if the patient exhibits moderate-severe symptoms, escalate treatment to that for persistent moderate-severe AR.
basis by an immunologist and often continued( for many years) under the supervision of the
Oral H1-antihistamine OR Intranasal antihistamine AND / OR Intranasal corticosteroid( combination nasal sprays are available) OR Oral decongestants OR Leukotriene-receptor antagonist
Review in 2-4 weeks
Moderate-severe
Intranasal corticosteroid
AND ONE OF Oral H1-antihistamine OR Intranasal antihistamine OR Leukotriene receptor antagonist
Review in 2-4 weeks to assess resolution of symptoms, consider some of the possible reasons of failed treatment:
• Nasal obstruction preventing drug delivery
• Concomitant nasal pathology( eg, polyps, septal deviation)
Initially, increase the dose or frequency of intranasal corticosteroids.
Consider referral to an ENT surgeon if treatment is unsuccessful after three months or if other concerning features develop in the history or examination.
NOTE: Agents listed in general order of preference.
Product
Table 6. Common medications used in the treatment of allergic rhinitis
Oral antihistamines Second generation( cetirizine, desloratadine, fexofenadine, loratadine) First generation( cyclizine, diphenhydramine, promethazine)
Intranasal antihistamines Azelastine, levocabastine
Intranasal corticosteroids Budesonide, fluticasone, mometasone
Combination intranasal antihistamine and corticosteroids Fluticasone propionate + azelastine
Leukotriene receptor antagonists Montelukast
Intranasal decongestants Oxymetazoline, phenylephrine, tramazoline, xylometazoline
Oral decongestants Pseudoephedrine, phenylephrine
Features
Second-generation oral antihistamines are preferred because of their greater tolerability and their lack of sedation.
Rapidly effective and generally well tolerated. Azelastine may cause somnolence.
Intranasal corticosteroids are the most efficacious agent in the treatment of AR. 8 There is minimal risk of systemic effect. If nasal congestion is the predominant feature, an intranasal corticosteroid should be considered in the first instance.
Per individual agents above.
Inhibits the leukotriene-mediated inflammation seen in AR. Montelukast is as effective as oral H1-antihistamines and inferior to intranasal corticosteroids in the treatment of AR. 8
Do not exceed five( preferably three) days of use
These agents play a limited role in the management of AR but may be of benefit in a select group of patients.
patient’ s GP. Patients, therefore, need to be prepared to commit cont’ d next page
|
Box 2. Measures aimed at reducing levels of aeroallergens
House dust mites
• Encase bedding in house dustmite impermeable covers
• Wash bedding on a hot cycle( 55-60 ° C)
• Replace carpets with hard flooring
• Acaricides
• Vacuum cleaners with integrated HEPA filters
Pets
• Remove cat / dog from home
• Keep pets out of main living areas / bedrooms
• HEPA-filter air cleaners
• Wash pet
Box 3. Managing allergic rhinitis in children
THERE is little difference between the medications and protocols for managing allergic rhinitis in children compared with adults. The exceptions are for intranasal and oral decongestants, all of which should not be used in children under six.
GPs are advised to check the product restrictions— even in children older than six— for some intranasal and oral decongestants. Weighting of differential diagnoses should be modified with age; allergic rhinitis is common in children, as are foreign bodies. It is not uncommon for a foreign body to remain in the nose for more than four weeks unbeknownst to parents and forgotten by the child.
One of the key elements in the management of children is the effective delivery of intranasal medications. Consider the following:
• Multiple convenient( and small) pump sprays are readily available.
• Several different delivery methods may need to be trialled before success is achieved.
• Older children may respond well to education and selfadministration.
• Education of parent and child is crucial to compliance and successful management.
|
Online resources
ASCIA. Skin prick testing for the diagnosis of allergic rhinitis. A manual for practitioners http:// bit. ly / 2qUaCDx
AIHW Allergic rhinitis(‘ hay fever’) in Australia November 2011 http:// bit. ly / 2sVefNY
References
1. Feng CH, et al. The united allergic airway: connections between allergic rhinitis, asthma, and chronic sinusitis. American Journal of Rhinology & Allergy 2012; 26:187-90.
2. Australian Bureau of Statistics. National Health Survey: Summary of Results, 2007-2008. Australian Government, Canberra, 2009.
3. AIHW. Allergic rhinitis(‘ hay fever’) in Australia. Australian Government, Canberra, 2011.
4. Mullins RJ, et al. The economic impact of allergic disease in Australia: Not to be sneezed at. ASCIA / Access Economics Report, November 2007. bit. ly / 1Np3dzK
5. Bousquet J, et al. Allergic rhinitis and its impact on asthma. Journal of Allergy and Clinical Immunology 2001; 108: S147-334.
6. Fokkens WJ. Antigen‐presenting cells in nasal allergy. Allergy 1999; 54:1130-41.
7. Robbins S, et al. Diseases of the Immune System. In Robbins and Cotran Pathologic Basis of Disease. Saunders / Elsevier, Philadelphia, PA, 2010.
8. Bousquet J, et al. Allergic rhinitis and its impact on asthma( ARIA) 2008. Allergy 2008; 1; 63( s86): 8- 160.
9. Corren J. Allergic rhinitis and asthma: how important is the link?. Journal of Allergy and Clinical Immunology 1997; 99: S781-86.
10. Burgess JA, et al. Childhood allergic rhinitis predicts asthma incidence and persistence to middle age: a longitudinal study. Journal of Allergy and Clinical Immunology 2007; 120:863-69.
11. Hu W, et al. Allergic rhinitis: Practical management strategies. Australian Family Physician 2008; 37:214.
12. Myers WA. The nasal crease: A physical sign of allergic rhinitis. Journal of the American Medical Association 1960; 174:1204-06.
13. Ramey JT, et al. Rhinitis medicamentosa. Journal of Investigational Allergology and Clinical Immunology 2006; 16:148.
14. Sheikh A, et al. House dust mite avoidance measures for perennial allergic rhinitis: an updated Cochrane systematic review. Allergy 2012; 67:158-65.
15. Björnsdottir US, et al. The effect of reducing levels of cat allergen( Fel d 1) on clinical symptoms in patients with cat allergy. Annals of Allergy, Asthma & Immunology 2003; 91:189-94.
16. Therapeutic Guidelines Limited. Allergic rhinitis. In: eTG complete [ online ]. 2015.
17. Australasian Society of Clinical Immunology and Allergy. Immunotherapy for treatment of allergy. 2014 [ online ]. bit. ly / 2tBSthq
|