What Is Non-allergic Rhinitis? What Causes Non-allergic Rhinitis?

When a person has rhinitis the inside of their nose becomes inflamed (swells), causing cold-like symptoms, such as itchiness, blocked nose, runny nose and sneezing. Rhinitis can be caused by an allergy (allergic rhinitis) or something else (non-allergic rhinitis). This article is about non-allergic rhinitis. The symptoms of non-allergic and allergic rhinitis are similar, but the causes are different.

Some individuals with non-allergic rhinitis often find they have a runny nose that does not seem to get better, while others find that symptoms keep recurring. The blood vessels inside the nose expand, causing the lining of the nose to swell. This stimulates the mucus glands in the nose, causing it to become congested and "drippy".

According to The Mayo Clinic, USA, and the National Health Service (NHS), UK, both children and adults are similarly affected by non-allergic rhinitis. Women tend to be more susceptible to nasal congestion during menstruation and pregnancy.

According to Medilexicon's medical dictionary:

Rhinitis is " Inflammation of the nasal mucous membrane."

The English medical word rhinitis comes from the Greek word rhinos meaning "nose" and the Greek suffix (word ending) itis meaning "inflammation".

There are different types of non-allergic rhinitis:

• Infectious rhinitis - also known as viral rhinitis. This is caused by an infection, e.g. the common cold or flu.
• Vasomotor rhinitis - the blood vessels in the nose are too sensitive, leading to inflammation. There is abnormal nerve (neuronal) control of the blood vessels in the nose, resulting in inflammation.
• Atrophic rhinitis - the membranes inside the nose become thinner and harder, causing the nasal passages to widen and become drier. Crusts form inside the nose, some of them foul smelling. The patient can lose his/her sense of smell. This type of rhinitis may be a complication of nose surgery or an infection.
• Other causes - some people may develop non-allergic rhinitis after taking certain medications, such as beta blockers, aspirin or the overuse of nasal decongestants (rhinitis medicamentosa). Sometimes pregnancy, puberty or an over-active thyroid gland can cause rhinitis (due to a hormonal imbalance). Eating spicy foods can cause rhinitis in some people (this is not allergic rhinitis because it is not caused by an immune system response).

What are the signs and symptoms of non-allergic rhinitis?

A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor detect. For example, pain may be a symptom while a rash may be a sign.

The signs and symptoms of infectious rhinitis, vasomotor rhinitis and rhinitis medicamentosa are similar, and they include:

• Sneezing
• A blocked nose
• A runny nose
• Nasal pressure
• Nasal pain
• Postnasal drip - phlegm (mucus) in the throat

The signs and symptoms of atrophic rhinitis include:

• Crusting inside the nose
• Crusts produce a foul smell
• The nose may bleed when the patient tries to remove the crust
• Anosmia - loss of the sense of smell

Individuals with non-allergic rhinitis do not generally have itchy nose, eyes or throat (allergic rhinitis symptoms).

What are the risk factors for non-allergic rhinitis?

A risk factor is something which increases the likelihood of developing a condition or disease. For example, obesity significantly raises the risk of developing diabetes type 2. Therefore, obesity is a risk factor for diabetes type 2. Risk factors for non-allergic rhinitis include:

• Irritants - people who are exposed to tobacco smoke, smog, exhaust fumes, and some other irritants are more likely to develop non-allergic rhinitis. People who work in environments with irritants, such as airplane fuel, jet exhaust, solvents, and some other substances have a higher risk.
• Overuse or prolonged use of nasal sprays and drops - people who use OTC (over-the-counter, no prescription required) decongestant drops or sprays for longer than a few days have a significantly higher risk of developing severe nasal congestion.
• Gender - females tend to be more susceptible to nasal congestion during menstruation and pregnancy.
• Some health conditions - individuals with lupus, cystic fibrosis, some hormonal disorders and asthma are more likely to develop non-allergic rhinitis, compared to other people.

What are the causes of non-allergic rhinitis?

Viral rhinitis - the lining of the nose and throat become inflamed when a virus attacks the area. Inflammation triggers the production of more mucus, which in turn leads to sneezing and a runny nose.

Vasomotor rhinitis - blood vessels inside the nose should contract and expand, thus helping to control the flow of mucus. If the blood vessels are oversensitive they can dilate when exposed to several kinds of environmental triggers, leading to congestion and too much mucus. Triggers include chemical irritants, perfumes, paint fumes, smoke, changes in humidity, a drop in temperature, consumption of alcohol, spicy foods and mental stress.

Atrophic rhinitis - atrophic rhinitis can occur if the turbinate tissue becomes damaged. The turbinate tissue refers to three ridges of bone that are covered by a layer of tissue inside the nose. Surgery is a common cause of turbinate tissue damage - if air flow is obstructed it is sometimes necessary to surgically remove turbinate tissue. Infection can damage turbinate tissue (more common in India, China and Egypt. Very rare in Western Europe and the Americas).

Turbinate tissue helps keep the inside of the nose moist, it protects against bacteria, helps regulate air pressure of the oxygen we breathe in, and contains nerve endings that give us our sense of smell. If some turbinate tissue is lost, the inside of the nose becomes dry, crusty and much more vulnerable to infection.

While some people need to lose a significant amount of turbinate tissue for atrophic rhinitis to develop, others need only lose a small amount.

Rhinitis medicamentosa - caused by over-use of nasal decongestants. In some cases it can be caused by cocaine use. Nasal decongestants reduce the swelling of the blood vessels inside the nose. If the patient uses nasal decongestants for more than five to seven days non-stop the lining inside the nose can start to become inflamed again - even after whatever caused the symptoms, such as a cold, has gone. If the patient carries on using decongestants to try to reduce the swelling, it will probably make the swelling worse (rebound congestion).

How is non-allergic rhinitis diagnosed?

Viral rhinitis - the signs and symptoms of an infection, as may be observed in a cold or flu, help a doctor diagnose viral rhinitis.

Vasomotor rhinitis - as this type of rhinitis has similar symptoms to allergic rhinitis, diagnosis is not so easy. There is no single test that can diagnose vasomotor rhinitis. Doctors use a system known as diagnosis through exclusion to be able to eventually make a diagnosis. All other potential rhinitis causes may have to be checked, including allergens, such as animal fur or pollen. This will include some allergy tests:

• Skin prick test - drops of diluted foods are placed on the patient's arm. The skin is then pierced through the drop, thus introducing the food into the system. If there is itching, redness or swelling, the indication is most likely a positive reaction. Experts say that negative results are 95% accurate, while positive results are 55% accurate.
• Blood test - the aim is to measure how much IgE (Immunoglobulin E) antibody there is in the blood. IgE is produced by the immune system in response to a suspected allergen.
• Patch test - a tiny amount of suspected allergen is added to metal discs which are then taped to the patient's skin. They remain there for up to two days. The health care professional then inspects the skin to see whether there has been a reaction. The test is generally done in hospital.

If the patient is found not have any allergic reactions, the doctor will probably diagnose vasomotor rhinitis.

Atrophic rhinitis - signs and symptoms, such as nasal crusting, widening of the passages in the nose, a foul smell, and the patient's loss of his/her sense of smell indicate that the patient has atrophic rhinitis.

CT (computerized tomography) scan - the CT scanner uses digital geometry processing to generate a 3-dimensional (3-D) image of the inside of an object. The 3-D image is made after many 2-dimensional (2-D) X-ray images are taken around a single axis of rotation - in other words, many pictures of the same area are taken from many angles and then placed together to produce a 3-D image. Doctors may use a CT scan to confirm diagnosis and check for changes in the nasal cavities.

Rhinitis medicamentosa - the doctor will ask the patient whether they have been using decongestant nasal sprays, and how long for. The patient needs to answer honestly. The doctor is interested in making a diagnosis, and will not judge or criticize the patient.

Ruling out a sinus problem - the doctor may want to determine whether the patient might have a deviated septum or nasal polyps. Either a nasal endoscopy or CT scan may be ordered.

What are the treatment options for non-allergic rhinitis?

Viral rhinitis - as the infection that caused the rhinitis usually goes away on its own, medical treatment for the rhinitis is not usually required. Nasal decongestants may help reduces swelling and blocked nose - it is important not to overuse as this may eventually make the congestion worse, leading to rhinitis medicamentosa. People taking MAOI (monoamine oxidase inhibitor) antidepressants should not take nasal decongestants.

Vasomotor rhinitis - an individual who has been diagnosed needs to try to avoid exposure to the environmental triggers that are causing vasomotor rhinitis. Corticosteroid nasal sprays may help reduce inflammation and congestion. If the patient does not respond, the doctor may try:

• Antihistamine nasal sprays - even though these are more commonly prescribed for patients with allergies, they sometimes help patients with vasomotor rhinitis.
• Anticholinergics nasal sprays - this medication helps widen the airways, which helps breathing. They also reduce the production of mucus.
• Sodium cromiglicate - reduces the production of mucus as well as inflammation. In most cases the medication is inhaled.

Atrophic rhinitis - nasal irrigation is most commonly recommended. A saline solution is inserted into the nasal cavities with the use of a syringe. Nasal irrigation is effective in treating crusting and dryness. If there is an infection - often the case if there is a foul smell - the patient will be prescribed an antibiotic.

The following surgical procedures are sometimes used to treat atrophic rhinitis:

• Young's operation - the nasal cavity is closed, usually for about nine months, after which it is reopened. This allows it to heal with a much lower risk of infection.
• Nasal narrowing - grafted bone or cartilage, and sometimes Teflon or silicon is used to narrow the affected nasal cavity. If the cavity is narrower crusting is less likely to occur.

Rhinitis medicamentosa - the patient needs to stop using the nasal decongestant spray. Some may find this difficult, especially if they have been using them for a long time. The following may help:

• Do not use the spray on the good nostril (or less congested one). The good nostril will eventually open up - then stop using it on the other nostril.
• There are some types of antihistamine, especially the older ones, that cause drowsiness and help the patient sleep. When taking them be careful not to drive or operate heavy machinery.
• Use a saline solution to naturally lubricate your nose.