Non-allergic rhinitis is swelling and inflammation of the inside of the nose. This is usually because swollen blood vessels and fluid in the nose block the nasal passages and stimulate the mucus glands resulting in a blocked or runny nose. Allergenic rhinitis is similar inflammation caused by an allergy.
The main causes of non-allergic rhinitis include:
- infection of the nose or throat (usually viral such as a cold but sometimes bacterial or fungal)
- external factors (e.g. smoke, fumes, perfume, changes in the weather, alcohol, spicy food, stress)
- medication (e.g. such as beta blockers)
- drug misuse (e.g. cocaine)
- overuse of nasal decongestant sprays
- hormone imbalance (e.g. during pregnancy, puberty or when taking the contraceptive pill)
- tissue damage (perhaps after earlier surgery)
Allergic rhinitis is the result of an allergic reaction to a trigger such as pollen, dust and certain animals, and may indicate an over-sensitive immune system. Your body reacts to the allergen
by producing antibodies which cause cells inside your nose and throat to become inflamed and produce excess mucus.
Allergens may be airborne (e.g. house dust mites, pollen and spores), or due to animals (commonly dogs, cats and rodents) or may be work-related (e.g. flour, latex or wood dust).
Common symptoms of allergic and non-allergic rhinitis include a blocked nose, a runny nose (with watery discharge), an itchy nose and sneezing. Other less common symptoms include a loss of smell, an itchy throat, face pain, headache and itchy, watery and red eyes. Rhinitis usually affects both nostrils.
Rhinitis is most commonly caused by a cold or hay fever. However, persistent rhinitis is where the symptoms do not disappear and become long-term. Sometimes the symptoms can be severe which may cause sleeping problems and interfere with day to day living.
Symptoms of both non-allergic and allergic rhinitis include:
- blocked and runny and nose
- itching, watery eyes
- persistent symptoms may cause sleep problems and interfere with daily activities.
Rarely, non-allergic rhinitis also causes a crust to develop inside the nose, which may be foul-smelling and cause bleeding if it’s removed.
You should see a doctor if you have symptoms that affect your quality of life. If the causes of your symptoms aren’t obvious, you may be referred to an Ear, Nose & Throat (ENT) specialist to have further tests. These may include allergy tests, blood tests or a further examination to eliminate other conditions such as sinusitis or nasal polyps. This may involve looking inside your nose with an endoscope, a small flexible instrument with a camera at the end.
Other tests include a nasal inspiratory flow test (to measure the airflow of your breathing) or computerised tomography (CT scan).