Describe the non-allergic rhinitides.

Classification and the Major Types

• Non-allergic rhinitis is inflammation or dysfunction of the nasal mucosa producing rhinitic symptoms without demonstrable IgE-mediated allergy.
• It is a diagnosis of exclusion, made when allergy testing is negative, and accounts for a substantial minority of all rhinitis.
• The clinical picture differs from allergic rhinitis in ways that are worth stating: itching and sneezing are less prominent; blockage and rhinorrhoea dominate; there is NO seasonal pattern and no personal or family history of atopy; onset is in adult life; and eye symptoms are absent
• Vasomotor (idiopathic) rhinitis is the commonest type — an imbalance of autonomic control of the nasal vasculature, with relative parasympathetic overactivity producing vasodilatation and secretion

Assessment and Management

• The history IS the diagnosis, and four questions do most of the work: what provokes it (physical triggers versus allergens); is there itching (suggesting allergy); what drugs are used, including sprays bought over the counter; and is it better away from work
• Examine for the appearance of the mucosa, septal deviation, polyps and crusting; and exclude the mimics
• The conditions that masquerade AS rhinitis and must BE excluded — chronic rhinosinusitis and nasal polyps; CSF rhinorrhoea in a unilateral clear watery discharge, particularly after trauma or surgery; a nasal tumour where symptoms are unilateral; a foreign body in a child with unilateral foul discharge; granulomatous disease where there is crusting and destruction; and primary ciliary dyskinesia or cystic fibrosis in a child
• Any unilateral rhinitic symptom deserves endoscopy.
• Investigation — allergy testing to exclude allergy, which is what defines the group; nasal smear for eosinophils; endoscopy; and CT where sinus disease is suspected
• Management:
• Identify and avoid the triggers where possible — which for vasomotor rhinitis means practical measures against cold air, smoke and strong smells rather than allergen avoidance
• Stop or substitute the offending drug, in discussion with the prescriber.
• Saline irrigation, which is safe, cheap and useful in all forms
• Topical intranasal steroid, which is the most effective drug for blockage and works in most non-allergic forms, particularly nares
• Topical anticholinergic (ipratropium) is the treatment of choice where watery rhinorrhoea is the dominant symptom — in vasomotor, gustatory and elderly rhinitis — because it blocks the parasympathetic secretomotor drive directly
• Topical antihistamine (azelastine) has an effect in vasomotor rhinitis beyond its antihistamine action, whereas oral antihistamines are of little value in non-allergic disease
• Capsaicin for intractable vasomotor rhinitis, acting by defunctionalising sensory C-fibres
• Surgery — turbinate reduction for irreversible hypertrophy, and septoplasty for obstruction; with vidian neurectomy, historically performed for intractable rhinorrhoea and now largely abandoned because of the risk of a dry eye from interrupting the lacrimal secretomotor supply
• Ask directly about over-the-counter sprays; patients do not volunteer them because a decongestant does not feel like a medicine
• Rhinitis medicamentosa is self-inflicted and curable, and the whole treatment is to stop the drug
• Warn that the nose worsens for a week or two after stopping, or the patient simply restarts the spray
• Stopping one side at a time is a practical strategy that many patients tolerate far better than stopping both
• Itching and sneezing suggest allergy, whereas blockage and watery discharge dominate non-allergic disease
• Physical triggers point to vasomotor rhinitis — cold air, strong smells, alcohol, emotion and spicy food
• Ipratropium is the drug for watery rhinorrhoea, blocking the parasympathetic secretomotor drive directly
• Oral antihistamines are of little value in non-allergic rhinitis, though topical azelastine has an effect beyond antihistamine action
• Improvement at weekends suggests occupational rhinitis.
• Recognising occupational rhinitis matters beyond the nose.
• Rhinitis of pregnancy resolves after delivery and should be managed with saline and posture rather than decongestants
• Check thyroid function where rhinitis is unexplained; hypothyroidism causes mucosal congestion
• Review antihypertensives as a cause; beta-blockers, ACE inhibitors and methyldopa all cause nasal congestion