Vincent St Aubyn Crump – Article Written: January 2003
Rhinitis is defined as an inflammation of the nasal mucosa and it is characterised by nasal obstruction, runny nose (rhinorrhea), sneezing, and (itching) pruritus.
The causes of rhinitis can be broadly categorised into 3 headings:
1. Allergic Rhinitis
- Seasonal – Hay Fever
- Persistent (perennial) eg House dust mite-induced
2. Infectious Rhinitis (eg the common cold)
Children, particularly young children in school or day care centres, may have from eight to 12 colds each year. Viral infections are self-limiting and usually last 7-10 days.
3. Non-allergic, Non-Infectious eg Vasomotor Rhinitis (or Irritant rhinitis)
"Vaso" means blood vessels and "motor" refers to the nerves, which innervates nasal tissue and the blood vessels. This is sometimes referred to as idiopathic non-allergic rhinitis. It is estimated that up to 10% of the population suffers from non-allergic rhinitis.
Mixed Allergic and Non-allergic Rhinitis
Mixed Allergic and Non-allergic Rhinitis probably account for the majority of cases. This is an important category to recognise, as allergen avoidance measures only, will give sub-optimal improvements.
Mixed Allergic and Vasomotor
Mixed Allergic and Vasomotor probably account for the majority of cases. This is an important category to recognise, as allergen avoidance measures only will give sub-optimal improvements.
Features of Vasomotor Rhinitis
Vasomotor Rhinitis is chronic rhinitis that is characterised by intermittent (coming and going) episodes of sneezing, watery nasal drainage (rhinorrhea), and blood vessel congestion of the nasal mucus membranes. There appears to be a hypersensitive response to stimuli such as a dry atmosphere, air pollutants, spicy foods, alcohol, strong emotions, and some medications. Indeed any particulate matter in the air, including pollens, dust, mould, or animal dander can bother people with VMR, even though they are not actually allergic to these things.
People with VMR are unusually sensitive to irritation and will have significant nasal symptoms even when exposed to low concentrations of irritants. Thus, vasomotor rhinitis seems to be an exaggeration of the normal nasal response to irritation, occurring at levels of exposure, which doesn't bother most people
Subjects with vasomotor rhinitis fall into two general groups: "runners" who have "wet" rhinorrhea, and "dry" subjects with predominant symptoms of nasal congestion and blockage to airflow, and minimal rhinorrhea. These reactions can be provoked by non-specific irritant stimuli such as cold dry air, perfumes, paint fumes, and cigarette smoke. Subjects with predominantly rhinorrhea (sometimes referred to as cholinergic rhinitis) appear to have enhanced cholinergic glandular secretory activity, since atropine effectively reduces their secretions.
It is important to understand that VMR is a nonspecific response to virtually any change or impurity in the air, as opposed to allergic rhinitis (or hay fever), which involves a response to a specific protein in pollen, dust, mould, or animal dander.
Key features of VMR:
- There is usually no history of allergies and an irritant may or may not be identified by the patient
- There is no infection causing these symptoms.
- Vasomotor Rhinitis can have a variable presentation.
- Most patients seem to be older than the typical patients with hay fever.
- Can sometimes present with a seasonal pattern due to changes in temperature and humidity.
- Patients present with rhinorrhea (thick or scanty), frontal headaches, and congested turbinates but usually no (itching) pruritus.
- Some patients will find that eating (especially, spicy foods) causes more nasal dripping or congestion.
The autonomic nervous system controls the blood supply into the nasal mucosa and the secretion of mucus. The diameter of the resistance vessels in the nose is mediated by the sympathetic nervous system while the parasympathetic nervous system controls glandular secretion and to a lesser extent, exerts an effect on the capacitance vessels. Either a hypoactive sympathetic nervous system or a hyperactive parasympathetic nervous system can engorge these vessels, creating an increased swelling of the nasal mucosa, and thus congestion. Activation of the parasympathetic nervous system can also increase mucosal secretions leading to excess runny nose.
Overactive irritant receptors may also play a role in Vasomotor Rhinitis.
Triggers of Vasomotor Rhinitis
Many cases are associated with a specific agent or condition. Examples of such agents/conditions are:
- Changes in temperature or barometric pressure, turbulent air
- Perfumes, strong cooking odours, smoke
- Inorganic dust (which is separate from house dust mite), air pollution
- Spicy foods, alcohol
- Some medications, like some blood pressure tablets
- Sexual arousal
- Stress (emotional or physical).
Other causes of non-allergic rhinitis are:
Nonallergic rhinitis with eosinophilia syndrome (NARES)
Eosinophilic rhinitis (ie, perennial intrinsic rhinitis) accounts for up to 20% of rhinitis diagnoses. Some researchers believe that this may be a precursor to the aspirin triad of intrinsic asthma, nasal polyposis, and aspirin intolerance. Abnormal prostaglandin metabolism also has been implicated as a cause of NARES. Elevated eosinophil counts are present in approximately 20% of the general population's nasal smears. However, not everyone with eosinophilia has symptoms of rhinitis. A distinguishing feature of NARES is the presence of eosinophils, usually between 10-20%, on nasal smear. Generally, patients with NARES present with nasal congestion, sneezing, rhinorrhea, nasal pruritus, and hyposmia.
Occupational rhinitis is usually caused by an inhaled irritant or allergen (eg, laboratory animal antigens, grains, wood dusts, and chemicals). Frequently patients with occupational rhinitis present with concurrent occupational asthma.
Hormonal rhinitis is caused by hormonal imbalances such as pregnancy, hypothyroid states, puberty, and oral contraceptive use, conjugated estrogen use.
Drug-induced rhinitis is caused by several medications including angiotensin-converting enzyme inhibitors, reserpine, guanethidine, phentolamine, methyldopa, beta-blockers, chlorpromazine, gabapentin, penicillamine, aspirin, nonsteroidal anti-inflammatory drugs, inhaled cocaine, exogenous estrogens, and oral contraceptives.
Rhinitis medicamentosa is considered a drug-induced rhinitis and results from prolonged use (ie, longer than 5-10 days) of over-the-counter topical nasal decongestants. Typically, these patients present with extensive nasal congestion and rhinorrhea, resulting from loss of sympathetic nerve tone, rather than from the original cause of rhinitis. Normal nasal function should resume within 7-21 days following cessation of decongestants. Symptoms usually improve with nasal steroids.
Gustatory rhinitis occurs following consumption of hot and spicy foods. This is a "wet" (profuse watery) runny nose, secondary to nasal vasodilatation (dilated blood vessels) and it is due to stimulation of the vagus nerve, generally occurring within a few hours of eating the food.
Conditions often confused with non-allergic rhinitis include:
- Nasal polyps
- Previous trauma to the nose
- Structural abnormalities eg deviated nasal septum
Diagnosis of VMR
VMR is usually diagnosed by taking a careful history and performing a thorough exam of the nose and throat. In addition, allergy testing (skin prick test) should be performed to make sure there is no allergic basis for some of the symptoms, since this would affect our treatment approach.
In some cases a CT scan of the sinuses may be required to exclude chronic sinusitis or polyposis. Occasionally, (few usually mild) positive skin prick test reactions are found in patients with VMR, but it does not fit the history and is therefore not relevant to the cause of the rhinitis.
Treatment of Vasomotor Rhinitis
Normal saline nasal douches
Antihistamines have a variable response. They seem to help a few patients whose main symptom is runny nose, and usually when the rhinitis is mixed vasomotor and allergic.
Atrovent (Ipratromium bromide) nasal spray is effective in patients who have runny nose as their main symptom.
Topical steroids help with congestion, runny nose, and sneezing. They suppress the local inflammatory response caused by vasoactive mediators by inhibiting Phospholipase A2, reduce the activity of acetylcholine receptors, and decrease basophil, mast cell, and eosinophil counts. They do not start working immediately, but when they do, they seem to control all the symptoms. Some adverse effects are mucosal swelling, mild redness, burning or stinging upon application, drying of the mucosa, nosebleeds, and nasopharyngeal thrush.
Decongestants, or sympathomimetic agents, are used mostly for congestion.
- Pseudoephedrine (Sudafed) tablets. Systemic adverse effects include nervousness, insomnia, irritability, and difficulty urinating in elderly males. They are contraindicated in persons with labile or overt hypertension. Decongestants have not been shown to have an effect on blood pressure in normotensive patients.
- Oxymetazoline (Drixine) nasal sprays
- Xylometazoline (Otrovine) nasal spray
Topically, these drugs can cause Rhinitis Medicamentosa (a rebound congestion which occurs after taking topical formulations of these drugs for more than five days).
If the rhinitis does not respond to drug therapy, very rarely surgical procedures can be considered. Some of the procedures that have been performed in the past include:
- Cryosurgery affects the mucosa and submucosa, making it a quite successful procedure for congestion. However, there is sometimes prolonged post-operative nasal congestion and the possibility of damage to the nasal septum.
- Vidian neurectomy disrupts both sympathetic and parasympathetic fibers to the mucosa and it mainly diminishes rhinorrhea.
If chronic hypertrophic changes appear in the mucosa, a number of surgical procedures can be tried. These include:
- Cauterization can be accomplished via silver nitrate or electrical current, however it only affects the mucosa.
Cryosurgery is considered superior to cauterization because it also affects the submucosa.
- Submucosal resection of the conchal bone is a difficult procedure with much post-operative bleeding. Partial or total inferior turbinate resection works well for nasal congestion but can give post-operative bleeding and crusting.