What is rhinitis?

Rhinitis is a medical term used to describe inflammation of the mucous membranes lining the nose. It is commonly referred to as “runny nose” or “nasal congestion”. Rhinitis can be caused by various factors, including allergies, infections, irritants, and hormonal changes.


Rhinitis can be classified into several types based on its cause and duration:

  • Allergic Rhinitis: Also known as hay fever, allergic rhinitis is triggered by allergens such as pollen, dust mites, pet dander, or mold spores. Symptoms typically occur seasonally or year-round, depending on the specific allergen.
  • Non-Allergic Rhinitis: This type of rhinitis is not caused by allergies but may be triggered by irritants such as smoke, strong odors, changes in temperature or humidity, or hormonal fluctuations. Non-allergic rhinitis can also be associated with certain medications or underlying medical conditions.
  • Infectious Rhinitis: Also known as the common cold, infectious rhinitis is caused by viral infections such as the rhinovirus. Symptoms may include nasal congestion, runny nose, sore throat, cough, and fatigue. Infectious rhinitis is typically self-limiting and resolves within a week or two.
  • Vasomotor Rhinitis: This type of rhinitis is characterized by nasal congestion and runny nose triggered by non-allergic factors such as changes in weather, temperature, or humidity, as well as strong odors or emotional stress.


What is the relationship between rhinitis and oxidative stress?

The relationship between rhinitis and oxidative stress has been studied, particularly in allergic rhinitis (AR), where oxidative stress is believed to play a role in the pathogenesis and exacerbation of symptoms.


  • Inflammation and Oxidative Stress: Allergic rhinitis is characterized by inflammation of the nasal mucosa in response to allergens such as pollen, dust mites, or pet dander. This inflammatory response involves the release of various inflammatory mediators, including cytokines, chemokines, and histamine. These mediators can stimulate the production of reactive oxygen species (ROS) by immune cells such as eosinophils and neutrophils, leading to oxidative stress in the nasal mucosa.


  • Airway Remodeling: Prolonged exposure to allergens and chronic inflammation in allergic rhinitis can lead to structural changes in the nasal mucosa, a process known as airway remodeling. Oxidative stress has been implicated in airway remodeling processes such as epithelial cell damage, fibroblast proliferation, collagen deposition, and smooth muscle hypertrophy. These changes can contribute to nasal congestion, nasal hyperreactivity, and impaired nasal function in allergic rhinitis.


  • Antioxidant Defenses: The nasal mucosa possesses antioxidant defense mechanisms to counteract oxidative stress and maintain redox balance. However, in allergic rhinitis, the antioxidant defense system may be overwhelmed or dysregulated, leading to increased oxidative damage. Studies have shown alterations in antioxidant enzyme activities and antioxidant molecule levels in the nasal mucosa of individuals with allergic rhinitis, suggesting a potential role for oxidative stress in the pathogenesis of the disease.


  • Exacerbation of Symptoms: Oxidative stress has been linked to the exacerbation of symptoms in allergic rhinitis. ROS can enhance the production of pro-inflammatory cytokines and chemokines, leading to increased nasal inflammation and symptom severity. Additionally, oxidative stress can impair nasal mucociliary clearance, disrupt epithelial barrier function, and promote sensory nerve activation, all of which can contribute to symptom exacerbation in allergic rhinitis.


Overall, while the exact mechanisms linking rhinitis and oxidative stress are still being elucidated, there is evidence to suggest that oxidative stress plays a role in the pathogenesis and exacerbation of symptoms in allergic rhinitis.