Allergy Ireland's Dr Iseult Sheehan features in the Irish Medical Times in August 2021.
Non-allergic rhinitis (NAR) describes nasal inflammation with a myriad of aetiologies which do not include allergy or infection. It is estimated that the prevalence of rhinitis within Europe is between 17 and 29%.(1) The UK has a prevalence of 26 per cent and Ireland is likely to be similar to this. (1) NAR is expected to represent approximately 25 per cent of this cohort.(2)
As their symptoms often mimic allergic rhinitis, it can be very disheartening for a patient to learn that they do not have an allergy. While it can be difficult to avoid allergens, at least they know what to avoid. There are many NAR triggers, and it is often very challenging to ascertain the cause of the symptoms. As such, NAR is a diagnosis of exclusion following negative skin prick testing and/or specific IgE testing.
Those with Non-Allergic Rhinitis experience chronic nasal symptoms including rhinorrhoea, nasal congestion, post-nasal drip, and often associated sinus symptoms, hyposmia and eustachian tube dysfunction. Occasionally NAR patients will experience sneezing and nasal or ocular pruritis despite these being more commonly associated with allergic rhinitis.
Rhinitis, both allergic and non-allergic, is also a strong risk factor for new onset asthma.2 NAR can be considerably debilitating for some, affecting sleep and functional capability, including cognitive and psychomotor function. It can result in reduced ability to work, or attend school, or to participate in social activities or sports.
There are two main subtypes of Non-Allergic Rhinitis:
- NAR with nasal inflammation on histology; and
- NAR without nasal inflammation on histology or local IgE production.
Management of NAR is based on the subtype and, in particular, whether NAR is inflammatory or not.
Non-allergic rhinitis with Eosinophilia syndrome (NARES)
NARES is an inflammatory rhinitis with the presence of eosinophils on nasal smear, despite a negative skin prick test. In addition to eosinophilia, histology may demonstrate elevated levels of mast cells, lymphocytes and local IgE.(2)
Patients experience perennial symptoms including rhinorrhoea, sneezing, nasal pruritis, hyposmia and often bronchial hyperreactivity. Half of these patients will develop the ‘aspirin triad’ of aspirin intolerance, nasal polyposis and aspirin induced asthma.(4) For these patients, an aspirin challenge will confirm the diagnosis, and they may also benefit from aspirin desensitisation where a challenge is positive. NARES will often respond well to anti-inflammatory treatment with topical corticosteroid nasal sprays and/or topical antihistamine nasal spray.
Autonomic Rhinitis (Vasomotor Rhinitis)
Autonomic rhinitis generally presents with profuse watery rhinorrhoea, particularly in the morning. These patients rarely experience sneezing or pruritis of the nasal cavity, palate or eyes.
It is most common in middle-aged patients. Although the cause is unknown it is likely related to an overzealous parasympathetic system due to dysfunction of the autonomic nerve supply to the nasal mucosa. This causes an imbalance between parasympathetic and sympathetic activity.(5)
These symptoms can be triggered by chemical irritants, stress and changes in temperature, humidity or barometric pressure. Chemical irritants can include strong odours such as scented candles, air freshener and perfumes, cigarette smoke, chlorinated pools, exhaust fumes and other pollution. Vascular engorgement with erythematous nasal mucosa is often visualised within the nasal cavity.
Management involves avoidance measures where possible. Humidified air and saline rinses can be beneficial. Topical Ipatropium bromide nasal spray can be useful for the management of watery rhinorrhoea. Topical capsaicin is often effective at reducing symptoms through desensitisation of the nasal cavity.(6)
Gustatory rhinitis is characterised by watery rhinorrhoea and facial flushing in response to the consumption of certain foods (spicy foods, hot soup, pepper), alcohol and/or sulphites. Occasionally certain additives, preservatives or colourings can trigger this reaction, for example, Monosodium Glutamate (MSG). It is diagnosed clinically, based on symptomatic response to these triggers, typically within two hours of ingestion. The elderly are particularly vulnerable to this condition. Ipratropium bromide nasal spray can be effective in the management of gustatory rhinitis.
Hormonal rhinitis is characterised by nasal congestion and rhinorrhoea associated with endogenous female hormones, including increased levels of oestrogen. This response can occur in puberty, pregnancy, peri-menopause and with oestrogen-based medications such as the oral contraceptive pill and hormone replacement therapy. Pregnancy rhinitis affects 20-30% of pregnancies, and can occur at any gestational week and will disappear within two weeks of delivery.(7) It is suspected that hypothyroidism is also associated with hormonal rhinitis whereby increased thyroid stimulating hormone (TSH) release results in turbinate oedema.
The primary symptom associated with drug-induced rhinitis is chronic nasal congestion. Rhinitis medicamentosa develops following prolonged use of nasal decongestants (greater than five days). This causes rebound vascular engorgement of the nasal mucosa and resultant nasal obstruction.
Other drugs can have a similar effect including ACE inhibitors, Beta-blockers, Alpha-adrenergic blockers and chlorpromazine. Aspirin and non-steroidal anti-inflammatory drugs can be associated with acute rhinitis and asthma symptoms.
Treatment requires removal of the offending medication. It can take seven to 28 days for the symptoms to resolve. On stopping medications, particularly topical decongestants, a patient may experience an initial worsening of symptoms. This can be mitigated by using a nasal corticosteroid during this time.
The European Drug Report 2020: Trends and Developments confirmed the high prevalence of cocaine use in Ireland with more than 2.5 per cent of young adults having used cocaine in the preceding year.(8) Ireland was also found to have the fifth highest use of cocaine in Europe over a 12-month period.(8) Cocaine is a trigger for drug-induced rhinitis. The symptoms include rhinorrhoea, nasal crusting, nasal pain, epistaxis, hyposmia and in some cases is associated with a septal perforation.(9) It is vital to discuss cessation with the patient, and to consider inclusion of drug addiction services where necessary. Emollients and humidified air can assist with pain, crusting and epistaxis. An ENT surgical opinion is recommended.
Occupational rhinitis results from exposure to an airborne substance in a workplace environment. Occupational rhinitis and asthma can co-exist although rhinitis is three times more common.2
More than 300 substances have been identified as inducing occupational rhinitis. It can be allergic driven (latex, flour, animal dander) or non-allergic driven (irritants such as wood or cement dust, chlorine, ammonia). It is diagnosed based on clinical history of symptoms worsening during the week while at work, and improving when away from work at weekends or during annual leave.
Skin prick allergy testing and a symptom diary can be helpful at establishing the diagnosis. Determining the causative agent and avoidance measures are the mainstay of treatment. Antihistamines and topical nasal corticosteroids can be used to assist with management.
Dr Iseult Sheehan
Clinical Director, Allergy Ireland,
MICGP, FRACGP, MB BAO, BCh, LRCP&SI, BA (Hons) Biochemistry and Immunology
- Bauchau V, Durham SR. ‘Prevalence and rate of diagnosis of allergic rhinitis in Europe’. European Respiratory Journal 2004; 24(5): 758.
- Scadding GK, Kariyawasam HH, Scadding G, et al. ‘BSACI guideline for the diagnosis and management of allergic and non-allergic rhinitis’ (Revised Edition 2017; First edition 2007). Clin Exp Allergy 2017; 47(7): 856-89.
- Sullivan AA, Kushnir, N.M. In-Depth Review of Allergic Rhinitis. World Allergy Organization. Updated 2020. Available at: www.worldallergy.org. [Last accessed on 19 July 2021].
- Leone C, Teodoro C, Pelucchi A, et al. ‘Bronchial responsiveness and airway inflammation in patients with nonallergic rhinitis with eosinophilia syndrome’. J Allergy Clin Immunol 1997; 100(6 Pt 1): 775-80.
- Garay R. ‘Mechanisms of vasomotor rhinitis’. Allergy 2004; 59 Suppl 76: 4-9; discussion-10.
- Leiberman, P.M. ‘Patient education: Nonallergic rhinitis (Beyond the Basics)’ Up To Date. Last updated: May 2021. Accessed via: https://www.uptodate.com/contents/nonallergic-rhinitis-runny-or-stuffy-nose-beyond-the-basics. Last accessed on: July 19, 2021.
- Ellegard EK. ‘Clinical and pathogenetic characteristics of pregnancy rhinitis’. Clin Rev Allergy Immunol 2004; 26(3): 149-59.
- European Monitoring Centre for Drugs and Drug Addiction. European Drug Report: Trends and Developments, 2020. Available at: www.emcdda.europa.eu/publications/edr/trends-developments/2020_en.
- Moreno-Artero E, Querol-Cisneros E, Rodríguez-Garijo N, et al. ‘Mucocutaneous manifestations of cocaine abuse: a review’. J Eur Acad Dermatol Venereol 2018; 32(9): 1420-6.