Other relevant separate articles include Allergic Rhinitis, Nasal Polyps, Rhinosinusitis and Rhinitis and Nasal Obstruction.
Non-allergic rhinitis can be defined as a condition causing profuse chronic watery rhinorrhoea which is not allergic in aetiology. It is a general term encompassing a number of conditions, which include:
- Vasomotor rhinitis.
- Occupational rhinitis.
- Hormonal rhinitis.
- Drug-induced rhinitis.
- Non-allergic rhinitis with eosinophilia syndrome (NARES).
Non-allergic rhinitis is a very common condition in adults. One Norwegian study found that 25% of the population suffered from the condition and nearly half had sought treatment for it. It is rare in children but increasingly common in the elderly.
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Common symptoms of non-allergic and allergic rhinitis include rhinorrhea, sneezing, itchy nose and nasal congestion. In both types, the symptoms can be intermittent or almost continuous. Either type can result in acute rhinosinusitis by causing blockage of intranasal passages. Both types may be associated with asthma.
- This features excessive vascular engorgement of the nasal mucosa and profuse, watery rhinorrhoea. The cause is unknown but it appears to be related to an imbalance in the regulation of the parasympathetic and sympathetic systems, with the parasympathetic predominating.
- It can be triggered by chemical irritants, changes in weather excess humidity or a very dry atmosphere and stress.
- The nasal mucosa can vary in colour from bright red to purple. Symptoms are usually intermittent.
- The turgescent mucous membrane varies from bright red to purple. The condition is marked by periods of remission and exacerbation.
Symptoms occur only in the workplace. Common inhaled irritants which trigger the condition include metal salts, animal dander, latex, wood dust and chemicals but over 300 substances have been identified. Occupational asthma may be an associated condition and is most likely to occur in the first year after the rhinitis develops.
Rhinorrhoea and nasal congestion are the principle symptoms. The condition may be linked to increases in oestrogen levels. Such states can occur in pregnancy, menstruation, puberty, and the use of oestrogen medication . In pregnancy the condition usually occurs in the second month and stops after delivery. Oestrogen is thought to act in several ways, including stimulating parasympathetic activity, increasing acetylcholine levels, inhibiting sympathetic neurons and increasing the levels of hyaluronic acid in the nasal mucosa.
Hypothyroidism can be another hormonal cause and is thought to be due to turbinate oedema resulting from the release of thyrotropic hormone release.
This is also known as rhinitis medicamentosa. Prolonged use of topical nasal decongestants may result in rebound congestion of the nasal mucosa. This congestion may encourage further use of the decongestant, which may exacerbate nasal obstruction.
Other drugs known to cause this include antihypertensives (eg angiotensin-converting enzyme (ACE) inhibitors, methyldopa, betablockers), chlorpromazine, gabapentin, penicillamine, aspirin, non-steroidal anti-inflammatory drugs (NSAIDs), cocaine, exogenous oestrogens and oral contraceptives.
This occurs after eating, especially hot and spicy foods. Vagus nerve activity causes nasal vasodilation, resulting in watery rhinorrhoea. Typically, this occurs two hours after ingestion. The elderly are particularly prone to this condition. Occasionally, specific dyes or food preservatives can cause the same reaction.
Non-allergic rhinitis with eosinophilia syndrome (NARES)
This is also known as perennial intrinsic rhinitis. 20% of rhinitis cases are suffering from this subtype. Presenting symptoms are rhinorrhoea, sneezing, nasal pruritus and hyposmia. It may be related to the 'aspirin triad' of aspirin-induced asthma, nasal polyposis and aspirin intolerance. Abnormal prostaglandin metabolism may be involved.
- The clear discharge of vasomotor rhinitis may differentiate it from the purulent discharge and crusting of infective rhinitis. No specific allergen can be identified in the history.
- Occupational rhinitis may be identified by a history of symptoms only occurring in the workplace. Provocation by nasal inhalation or skin testing may be needed to confirm the trigger irritant.
- Patients with NARES may have a higher than normal amount of eosinophils seen on a nasal smear.
- Humidified air may be helpful.
- Topical antihistamines (eg azelastine) are the usual first-line medical treatment.
- Sympathomimetic amines (eg pseudoephedrine) can be effective but topical formulations (eg ephedrine nasal drops) are only licensed for use up to 7 days. Prolonged use can lead to rebound congestion on withdrawal (see 'Rhinitis medicamentosa', below). Ephedrine causes fewer problems than oxymetazoline and xylometazoline in this respect. Oral preparations have fewer systemic side-effects compared with drops. They are not licensed for use in children under the age of six.
- Topical corticosteroids (eg beclometasone) may be beneficial in some cases.
- Trans-nasal vidian neurectomy (severance of the preganglionic fibres that reach the sphenopalatine ganglion through the vidian nerve) is used less often than it was but is still sometimes employed in severe cases unresponsive to conservative therapy. An endoscopic approach has been successfully used.
- Intra-turbinate injection of botulinum toxin A has been reported in a small trial as being beneficial.
Avoidance of the trigger irritant is the ideal treatment but cannot always be achieved in reality. Nasal corticosteroids and second-generation antihistamines are the medical treatments of choice.
Management will depend on the underlying condition. Pregnant patients may present with vasomotor rhinitis and may benefit from nasal saline solution, exercise and topical pseudoephedrine.
Treatment depends upon removal of the offending medication. In terms of sympathomimetics, it takes 7-21 days for the condition to resolve. Patients may be resistant to withdrawal of the preparation, as symptoms are likely to increase as it is withdrawn but this may be mitigated by using a nasal corticosteroid during this period or by reducing medication gradually (eg one nostril at a time).
Ipratropium bromide nasal spray is useful in this condition. The elderly may be troubled by its adverse effects of loss of bladder control. An oral antihistamine would be a second-line option.
Non-allergic rhinitis with eosinophilia syndrome (NARES)
Steroid nasal sprays are useful, as they appear to have a direct action on eosinophils, preventing the activation of the allergic cascade which leads to inflammation.
Non-allergic rhinitis can affect quality of life considerably. It is associated with interrupted sleep patterns, daytime drowsiness, irritability and poor concentration.
Further reading & references
- Ramakrishnan V et al; Pharmacotherapy for Nonallergic Rhinitis, Medscape, Apr 2010
- Pinto JM, Jeswani S; Rhinitis in the geriatric population. Allergy Asthma Clin Immunol. 2010 May 13;6(1):10.
- Rhinitis, Merck Manuals (2008)
- Guidelines for the management of allergic and non-allergic rhinitis, British Society for Allergy and Clinical Immunology (January 2008)
- British National Formulary
- Archer S; Turbinate Dysfunction, Medscape, Feb 2009
|Original Author: Dr Laurence Knott||Current Version: Dr Laurence Knott|
|Last Checked: 20/04/2011||Document ID: 13210 Version: 1||© EMIS|
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