Intrinsic Rhinitis

By

Dr. T. Balasubramanian M.S. D.L.O.

Synonyms: Non infective rhinitis, Non allergic rhinitis, Vasomotor rhinitis, Perenial rhinitis..

Definition:Intrinsic rhinitis is defined as a non infective and non allergic condition characterised by nasal block, rhinorrhoea and hyposmia. This is purely a medical condition.

Intrinsic rhinitis encompasses two separate disease entities. These entities show 1. inferior turbinate hypertrophy and 2. nasal polyp formation.

Clinical presentation: Rhinitis is generally characterised by 6 main symptoms: They are

1. Congestion

2. Sneezing

3. nasal itching

4. rhinorrhoea

5. hyposmia

6. post nasal discharge

Among these main symptoms nasal itching and sneezing are features of allergic rhinitis and hence are not seen in intrinsic rhinitis. All the other symptoms are manifested in intrinsic rhinitis.

Seebohm identified two groups of patients amongst those suffering from perenial rhinitis. One group had eosinophils in their nasal secretions while the other did not have any eosinophils in their nasal secretions. Accordingly he classified intrinsic / perenial rhinitis into eosinophilic and non eosinophilic types.

Eosinophilic group: This group is characterised by marked nasal congestion, profuse rhinorrhoea, hyposmia, inferior turbinate hypertrophy and mucoid nasal secretion. Nasal polyposis frequently occurred in this group of patients.

Non eosinophilic group: In these patients nasal obstruction is very mild, rhinorrhoea is very severe. They donot have significant mucosal swelling. Inferior turbinate hypertrophy is not significant. Tendency of nasal polyp formation is rare in this group.

Table showing the differences between eosninophilic and non eosinophilic types of intrinsic rhinitis

Aetiology of intrinsic rhinitis:

Theories regarding aetiology of intrinsic rhinitis are:

1. Autonomic imbalance

2. Airway hyperreactivity

3. Allergic reaction to unidentified allergen

4. Disturbances of Beta receptor function

Mechanisms of Beta receptor dysfunction:

1. Down regulation caused by excess endogenous noradrenaline stimualtion.

2. Down regulation and uncoupling of adenylate cyclase produced by the inflammatory mediator induced activation of protein kinase.

3. The action of Beta receptor inhibitory factor presumed to be an anti beta receptor autoantibody.

4. Dysfunction of Beta receptor kinase causing short term desensitisation of beta receptors after exposure to beta agonists.

Role of autonomic nervous system in causing intrinsic rhinitis:

The autonomic nervous system exerts its effects by secreting neurotransmitters ar their nerve endings. The neurotransmitters secreted are adrenaline, noradrenaline, vasoactive intestinal polypeptide, acetylcholine and neuropeptide Y.

The following transmitters are secreted by parasympathetic nerve endings: Acetyl choline, vaso active intestinal polypeptide.

The following transmitters are secreted by sympathetic nerve endings: adrenaline, noradrenaline, neuropeptide Y.

The nasal resistance to air flow is controlled by sympathetic system, whereas the nasal glands are innervated by parasympathetic nerves. Increased parasympathetic outflow causes glandular hypersecretion. Vaso active intestinal polypeptide has been known to cause this effect. The vasodilatation caused due to the effects of vaso active intestinal polypeptide is resistant to the effects of atropine.

Management:

Majority of patients with intrinsic rhinitis benefit from medical management. Only a few require surgical management.

Medical management of intrinsic rhinitis:

Eosinophilic type:

Steroids - Topical e.g. fluticasone, budesonide. A short course of systemic steriods can be administered.

Alpha receptor agonists - Systemic e.g. pseudoephidrine Topical e.g. xylometazoline (short course)

Mast cell stabilisers - Topical cromoglycate solution.

Non eosinophlic type :

Anti cholinergic - Topical e.g. ipratropium Hyosine administered orally or as a patch.

Anti cholinergic / sympathomimetic - Imipramine orally, chlorpheniramine orally.

Table showing the surgical indications for treatment of intrinsic rhinitis