Definition

The nose is one of the respiratory organs. The inner wall of the nose consists of several layers. The top layer that directly contacts the incoming air is called the nasal mucosa.

Rhinitis is inflammation that occurs in the mucosal layer inside the nose. There are several causes of rhinitis, such as infections, direct allergic responses, inhaled irritants, medications, hormonal disorders, and nervous system disorders.

In general, rhinitis can be classified into three groups: allergic rhinitis, non-allergic rhinitis, and infectious rhinitis.

Allergic rhinitis is inflammation of the nasal mucosa caused by exposure to allergens such as pollen, dust, mold, animal dander, or insect debris. Allergic rhinitis is a type 1 hypersensitivity response mediated by an antibody called IgE against inhaled allergens from the environment. Unlike allergic rhinitis, non-allergic rhinitis is inflammation of the nasal mucosa that occurs without a clear cause.

Infectious rhinitis is inflammation of the nasal mucosa caused by a viral or bacterial infection. The most common type of infectious rhinitis is acute viral rhinitis.

Causes

Allergic Rhinitis

The cause of allergic rhinitis is the immune system's response to allergens, perceiving these substances as harmful to the body. The immune cells then respond to avoid these perceived threats. This mechanism causes exposure to allergens to trigger allergic rhinitis. Some allergens include proteins from airborne particles such as pollen, dust, insect debris, animal dander, and mold.

Non-Allergic Rhinitis

The exact cause of non-allergic rhinitis is unknown. Generally, non-allergic rhinitis occurs when blood vessels in the nose dilate. One possible cause is overly responsive nerve endings in the nose.

Triggers for non-allergic rhinitis include:

• Environmental or occupational irritants like dust, cigarette smoke, smog, or strong odors.
• Changes in weather, temperature, or humidity can cause swelling of the nasal membranes, leading to a runny or congested nose.
• Hot or spicy foods and alcoholic beverages can trigger non-allergic rhinitis.
• Some medications, such as aspirin, ibuprofen, and beta blockers used for high blood pressure, can cause non-allergic rhinitis.
• Hormonal changes due to pregnancy, menstruation, oral contraceptive use, and other hormonal conditions can trigger non-allergic rhinitis.

Infectious Rhinitis

In general, infectious rhinitis can be caused by rhinoviruses, coronaviruses, adenoviruses, influenza viruses, parainfluenza viruses, syncytial viruses, and enteroviruses. These viruses can damage cells in the inner nasal wall (epithelial cells) and dominate the host cell's metabolism. The virus uses the host cell to multiply, causing damage and death to the host cell.

Risk Factor

Several risk factors for rhinitis include:

• Family history of allergies.
• Having asthma or atopic eczema.
• Exposure to irritants like smoke can increase the risk of non-allergic rhinitis.
• Long-term use of decongestant sprays.
• Hormonal changes during menstruation and pregnancy.
• Hypothyroidism and diabetes can cause or worsen allergic rhinitis

Symptoms

Symptoms of rhinitis include:

• Nasal congestion or runny nose
• Sneezing
• Mucus in the throat
• Cough

Diagnosis

Your doctor will ask several questions about your symptoms. Rhinitis is diagnosed based on your symptoms. Your doctor will also perform a physical examination and additional tests. If allergic rhinitis is suspected, your doctor may recommend allergy testing.

Allergy tests can be done with skin tests. Skin tests determine if your symptoms are caused by specific allergens. This is done by pricking your skin and exposing it to small amounts of common allergens, such as dust mites, mold, pollen, and animal dander. If you are allergic to a particular allergen, a bump will likely appear at the test site on your skin. If not, your skin will look normal. Blood tests can also be done to detect allergies. This test measures specific antibody responses in your blood known as immunoglobulin E (IgE) antibodies. The blood sample is sent to a medical laboratory for allergen sensitivity testing.

The initial symptoms of infectious rhinitis are similar to those of allergic rhinitis. What distinguishes the two types of rhinitis is the thick nasal discharge in infectious rhinitis. Generally, patients with infectious rhinitis do not experience itching in the nose and eyes. In allergic rhinitis, there is no history of allergies, ruling out allergic rhinitis.

In non-allergic rhinitis, a physical examination called anterior rhinoscopy is performed. In anterior rhinoscopy, the nasal conchae appear red and swollen. The conchae are structures in the inner nose. In allergic rhinitis, the conchae appear pale. In infectious rhinitis, the mucosa appears swollen and red with thick nasal discharge, indicating acute inflammation with bacterial infection.

Management

In general, symptoms of infectious rhinitis can resolve on their own without medical therapy. Antibiotics are not given for viral rhinitis unless there is a bacterial infection. Besides treating the cause, your doctor will also prescribe medications to reduce rhinitis symptoms. Your doctor may provide medication to relieve itching in the nose and eyes, cough, nasal congestion, and sneezing.

Additionally, you can regularly rinse your nasal passages with a saline solution to keep your nose free of irritants.

In some cases of non-allergic rhinitis caused by a deviation or abnormality in the nasal septum or persistent nasal polyps, your doctor may recommend surgery.

Complications

Some complications of rhinitis include:

• Nasal polyps: an abnormal non-cancerous fluid-filled growth in the nasal or sinus lining due to chronic inflammation. Large polyp can block airflow through the nose, causing breathing difficulties.
• Sinusitis: non-allergic rhinitis can cause prolonged nasal congestion, increasing the risk of sinusitis.
• Middle ear infection: infection in the part of the ear behind the eardrum can occur due to pathogens or bacteria causing rhinitis traveling to the middle ear through the Eustachian tube.

Prevention

Preventive strategies for rhinitis include:

• Avoiding contact with known or suspected allergies or irritants.
• Avoid using nasal decongestants too frequently, as this may damage the nasal mucosa.

When to See a Doctor?

See a doctor immediately if you experience severe symptoms, symptoms that do not improve with over-the-counter medications or self-care, or side effects from medications that are bothersome.