Nonallergic rhinitis

Overview

Nonallergic rhinitis, characterized by symptoms such as sneezing, nasal congestion, and a runny nose, can be a chronic condition with an unclear underlying cause. While its symptoms may resemble those of allergic rhinitis (hay fever), it’s important to note that nonallergic rhinitis is not driven by allergies.

This condition can affect individuals of all ages, but it tends to be more prevalent in adults, particularly those over the age of 20. The triggers for nonallergic rhinitis can vary from person to person and may include:

• Airborne irritants like dust and fumes.
• Changes in weather.
• Certain medications.
• Consumption of hot or spicy foods.
• Underlying chronic health conditions.

Medical professionals typically begin by ruling out allergies as the cause of symptoms. Therefore, you may undergo skin or blood tests to determine if you have allergic rhinitis.

Symptoms

Nonallergic rhinitis symptoms often fluctuate year-round and may include a congested or runny nose, sneezing, throat mucus, and occasional coughing.

Notably, nonallergic rhinitis rarely leads to the itching of the nose, eyes, or throat, which is a common allergy symptom such as in hay fever.

Causes

The precise cause of nonallergic rhinitis remains unknown, but experts have identified that it occurs due to the dilation of blood vessels in the nasal passages. These expanded blood vessels lead to swelling in the nasal tissue, resulting in symptoms like congestion and excessive mucus production. While the exact triggers can vary, they all contribute to this common outcome:

• Irritants in the air: Nonallergic rhinitis can be initiated by exposure to airborne irritants such as dust, smog, cigarette smoke, and strong odors like perfumes. Chemical fumes, which individuals may encounter in certain occupational settings, can also induce these symptoms.
• Dietary factors: Consumption of hot and spicy foods can trigger nonallergic rhinitis. Additionally, alcohol intake can lead to swelling of the nasal tissues, resulting in nasal congestion.
• Weather: Fluctuations in temperature and humidity levels can prompt inflammation in the nasal lining, causing a runny or congested nose.
• Infections: Viral illnesses like the common cold or the flu are frequent culprits behind nonallergic rhinitis.
• Medications: Certain medications, including aspirin, ibuprofen, beta blockers used for high blood pressure, sedatives, antidepressants, birth control pills, and drugs for erectile dysfunction, can induce nonallergic rhinitis. Overuse of decongestant nasal sprays or drops can lead to a specific type known as rhinitis medicamentosa.
• Hormonal changes: Nonallergic rhinitis may be associated with hormonal fluctuations, such as those occurring during pregnancy, menstrual cycles, or the use of birth control methods. Hypothyroidism, a condition resulting from insufficient thyroid hormone production, can also serve as a trigger.
• Sleep-related factors: Certain sleeping positions, particularly lying on one’s back, can exacerbate nonallergic rhinitis. Additionally, nocturnal acid reflux can act as a trigger during sleep.

Risk factors

Factors that can increase your susceptibility to nonallergic rhinitis include:

• Age over 20: Nonallergic rhinitis is more commonly observed in individuals aged 20 and above. This sets it apart from allergic rhinitis, which often manifests in individuals younger than 20.
• Exposure to unclean air: Inhaling certain types of polluted air, such as smog, exhaust fumes, and tobacco smoke, can elevate the risk of developing nonallergic rhinitis.
• Prolonged use of nasal sprays or drops: It is advisable to avoid extended use of over-the-counter decongestant drops or sprays containing oxymetazoline (brands like Afrin and Dristan) for more than a few days. Overuse may lead to a worsening of nasal congestion, a phenomenon known as rebound congestion.
• Underlying health conditions: Certain chronic health conditions, such as diabetes and hypothyroidism (insufficient thyroid hormone production), can either cause nonallergic rhinitis or exacerbate its symptoms.
• Pregnancy or menstruation: Hormonal changes during pregnancy or menstrual cycles can exacerbate nasal congestion in individuals susceptible to nonallergic rhinitis.
• Occupational exposure to fumes: Some professions entail exposure to fumes from materials and chemicals, which can trigger or worsen nonallergic rhinitis. Common triggers include construction materials and various chemicals. Additionally, exposure to compost fumes can also contribute to the condition.