Non-Allergic Perennial Rhinitis: Causes, Symptoms, and Treatment Options

What is Non-Allergic Perennial Rhinitis

IgE or eosinophil count are normal in non-allergic perennial rhinitis, but symptoms are the same with allergic rhinitis. The symptoms are not seasonal in nature and are present throughout the year. NAR (non-allergic rhinitis): exhibit symptoms intermittently and not throughout the year.

What is Rhinitis?

Rhinitis means inflammation of the nose. Rhinitis can be either infectious or non-infectious. Infectious rhinitis can be caused by either bacterial, viral, fungal, or protozoan infections. Non-infectious rhinitis can be further divided into allergic and non-allergic rhinitis. So, the term “non-allergic rhinitis” can be commonly applied to a diagnosis of any nasal conditions whose symptoms appear identical to allergic rhinitis, but allergic rhinitis has been excluded on the basis of diagnostic tests.

Differential Characteristics of Non-allergic Rhinitis and Allergic Rhinitis

NAR can be further subdivided

• Idiopathic rhinitis/vasomotor rhinitis, or non-allergic non-infectious perennial rhinitis (NANIPER)
• Non-allergen occupational rhinitis
• Hormonal rhinitis
• Drug-induced rhinitis

Other forms: Non-allergic rhinitis with eosinophilia syndrome (NARES), rhinitis due to physical and chemical factors, food-induced rhinitis, emotion-induced rhinitis, and atrophic rhinitis.

Pathophysiological considerations

NAR is the outcome of an imbalance between the sympathetic and parasympathetic nervous systems, leading to an imbalance in the neuronal control of the end organs in the nose. The sympathetic nervous system causes vasoconstriction, leading to reduced blood flow to the mucosa, resulting in its shrinkage (good airway space) and decreased mucus production, ultimately resulting in a dry nose.

The parasympathetic nervous system is responsible for vasodilation, leading to enhanced blood supply, mucosal enlargement (boggy mucosa), and increased mucus production.

• Mucosal enlargement leads to compromised or poor airway space.
• Hence, the symptomatic presentation of rhinorrhea (runny nose/nasal discharge), nasal blockage, sneezing, itching, foreign body sensation, etc.

So, during NAR, there is parasympathetic nervous system hyperactivity and sympathetic nervous system hypoactivity, resulting in parasympathetic excess leading to mucosal enlargement.

At the microscopic level, our respiratory mucosa consists of pseudostratified ciliated columnar epithelium, the cross section of which shows hair cells resting on goblet cells. These goblet cells are typical mucin-producing cells responsible for producing nasal discharge. Below this layer, there are seromucous glands and venous sinusoids lying in the submucosal space.

Whenever there is an increase in parasympathetic nervous system activation owing to many factors such as emotions, stress, and exposure to irritants, there will be increased nasal discharge.

Cause of Excess Nasal Discharge

• Excess blood supply to goblet cells. This further leads to stasis; hence, ciliary motility gets defective.
• Overactivity of seromucous glands
• Dilatation and congestion of venous sinusoids lead to bulging of the entire epithelial structure.

Also read: Olfactory Disorders – Pathway, Work up And Causes

Subdivision of NAR

Idiopathic Rhinitis

Also known as vasomotor rhinitis or non-allergic noninfectious perennial rhinitis (NANIPER). It is usually triggered by environmental changes such as temperature/humidity changes or due to the presence of irritants in the atmosphere. These factors will precipitate the imbalance between the parasympathetic and sympathetic nervous systems. The symptoms are known to increase progressively with age and can reach more than 60% in patients with chronic symptoms aged ≥ 50, thereby exhibiting that this functional abnormality has an association with the nasal mucosa's aging process. Major symptoms include nasal blockage, rhinorrhea, and sneezing.

Based on these symptoms, the patients would usually be divided into runners (major complaints of rhinorrhea) and blockers (predominantly complaining of nasal congestion and blockage).

Additionally, the patient might complain of headaches, facial pain, and smell disturbances.

Non-Allergic Occupational Rhinitis

Certain occupations, like mining and aircraft industries, expose their workers to environmental stimuli, which can lead to the development of rhinitis. Symptomatic manifestations include sneezing, nasal discharge, and/or nasal blockage. Exposure to irritants can damage the epithelial cells of nasal mucosa, which can trigger the release of pro-inflammatory

mediators, causing inflammation and clinical manifestation.

Also read: Relationship between the Upper and Lower Respiratory Tract

Hormonal Rhinitis

Hormonal rhinitis can occur during puberty and/or pregnancy due to high fluctuations in hormones. Estrogen is responsible for vascular engorgement in nasal mucosa resulting in nasal obstruction and or nasal hypersecretion, in addition to engorgement of the genital

tract. Estrogens can lead to increased activity of H1 receptors in the nasal mucosa, which can cause a release of inflammatory mediators, thereby triggering rhinitis symptoms.

In most pregnancy cases and puberty-induced hormonal fluctuations, the symptoms are resolved once the hormones stabilize. However, if hormonal rhinitis is the result of hormonal

dysfunction such as polycystic ovarian syndrome (PCOS), endometrial disorders, fibroids, ovarian disease, etc., then the cause needs to be resolved.

During an OPD practice, it is imperative to identify the factors behind the nasal blockage, sneezing, etc. to diagnose the etiology of rhinitis and choose an appropriate approach for patient management.

In case of suspicious hormonal rhinitis, a gynecological checkup should be recommended, and if/when confirmed, gynecological treatment should be sought to stabilize the hormones of the patient.

Drug-induced rhinitis

Rhinitis occurs as a side effect of drugs.

• Aspirin
• Non-steroidal anti-inflammatory drugs (NSAIDs)
• Antihypertensives such as beta-blockers and angiotensin-converting enzyme (ACE) inhibitors
• Methyldopa
• Oral contraceptives
• Psychotropic agents and nasal topical decongestants
• Neostigmine
• Guanethidine

Also read: Nasal Polyposis: Clinical Types, Causes, Pathogenesis And

Non-allergic rhinitis with eosinophilia syndrome (NARES)

Using a nasal cytology procedure, NARES can be diagnosed by the presence of more than 20% eosinophils in the nasal smears of symptomatic patients with perennial attacks, profuse watery rhinorrhea, nasal pruritus, incomplete nasal obstruction, and occasional loss of smell.

The NARES patients are disposed to develop nasal polyps and asthma later in life.

Therefore, these NARES need to be treated as a unified airway disease. Obstructive sleep apnea (OSA) can also be a future risk in NARES patients. NARES is also known as perennial intrinsic rhinitis.

Therapy for non-allergic perennial rhinitis

The therapeutic intervention is aimed at treating nasal discharge. Intranasal anticholinergics such as ipratropium bromide, although not commonly used due to side effects, topical steroids, and antihistamines (Azelastine). In patients who are not responding to nasal steroids or

antihistamines, the following non-conventional approaches can be employed:

• Silver nitrate
• Botulinum toxin
• Intranasal capsaicin
• Endoscopic transnasal Vidian neurectomy

Surgery for reduction of turbinates using laser, coblation, radio frequency, and microdebrider. Post these procedures, even if there is parasympathetic hyperactivity, mucosa will not be boggy due to reduction and fibrosis of submucosal space, thereby diminishing the symptoms.

Also read: Tumors of Nose and Sinuses Types

Points to Remember

• Around 50% of rhinitis patients suffer from NAR.
• No specific diagnostic tests are available to detect NAR.
• A thorough case history is the best diagnostic tool and shall focus on drug intake, hormonal profile, work exposure, etc., to classify NAR into subgroups.
• In chronic alcoholics, after other causes of rhinitis are ruled out, simple case history can aid in deciding preventive and treatment measures.
• The history of the patient is critical in diagnosing the NAR condition.

Also read: Nasal Septal Deviation: Causes, Types, Clinical Features and

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