Rhinitis (nasal mucosal inflammation) may be classified as being either infective or non-infective and the latter further sub-divided into allergic and non-allergic rhinitis. Non-allergic rhinitis (NAR) is a diagnosis of exclusion. In a 2007 Danish study, it was found to affect a quarter of the population, of which half sought medical advice.
NAR accounts for about half of perennial rhinitis cases. It becomes more common with increasing age. Although NAR is common and significantly impacts on quality of life, it is surprisingly often under-treated. It has a multifactorial aetiology and is a risk factor for the development of asthma. For patients who do not have adequate symptom relief from medication, turbinate reduction surgery is effective in reducing nasal blockage.
NAR has been divided into two types:
1. NAR associated with an identifiable cause.
2. Idiopathic rhinitis (previously called vasomotor or intrinsic rhinitis).
Eosinophilic rhinitis is usually placed in the idiopathic group because although such patients have a high number of eosinophils in their nasal mucous, the cause of this is unknown. Some patients demonstrate an intrinsic mucosal disorder of prostaglandin metabolism and there is an association of this type of rhinitis with aspirin hyper-sensitivity, asthma and aggressive nasal polyposis.
Regardless of the underlying aetiology, most patients demonstrate glandular hyperplasia and sub-mucosal vascular dilation. The nasal mucosa, particularly turbinate mucosa, becomes hyperaemic and hypertrophic. Eosinophil-laden polyps are more common in NAR than in allergic rhinitis (AR).
84.2 Predisposing Factors
• Familial tendency.
• A preceding nasal infection (nasal mucosal hyper-reactivity following viral or bacterial rhinitis).
• Occupational, such as irritation from hairsprays in hairdressers or chlorine in swimming instructors.
• Psychological and emotional factors.
• Endocrine (puberty, menstruation and pregnancy).
• Drugs (angiotensin-converting enzyme [ACE] inhibitors, β-blockers, methyldopa, aspirin and oral contraceptives).
• Pollution (atmospheric pollution, fumes, dust, industrial detergents and cigarette smoke).
• Climate changes in humidity and temperature.
84.3 Clinical Features
• Anterior and posterior rhinorrhoea.