Allergic Rhinitis

Allergic Rhinitis: Mechanism, Complications and Modern Management

Allergic rhinitis is one of the most common chronic conditions worldwide, affecting approximately 20% to 25% of the general population. It is an immune-mediated inflammation of the nasal mucosa, triggered when the immune system mistakenly identifies harmless environmental substances (aeroallergens) as potentially harmful “invaders.”

Mechanism & Pathophysiology

When a sensitized individual comes into contact with aeroallergens (such as pollen, house dust mites, molds, or animal dander), a cascade of biological reactions is triggered:

Immediate Phase (first 15–30 minutes): Specific antibodies (IgE) activate cells in the nasal mucosa, leading to the rapid release of histamine and other inflammatory mediators. This results in the immediate onset of symptoms: paroxysmal sneezing (repeated episodes of sneezing), watery nasal discharge, and itching of the nose and throat.
Late Phase (after 4–8 hours): Inflammatory cells accumulate in the affected area, sustaining the inflammatory response and causing significant swelling of the nasal mucosa. This phase is mainly responsible for persistent nasal congestion.

Types & Classification

Depending on the distribution of symptoms throughout the year, allergic rhinitis is classified as:

Seasonal: Symptoms occur during specific periods of the year, such as the spring months (March to June), mainly due to the flowering and pollination of trees such as olive trees and grasses. The main seasonal aeroallergens include tree pollen (e.g. olive and cypress), grass pollen, and weed pollen.
Perennial: Symptoms occur throughout the year, as they are caused by allergens to which exposure is continuous, regardless of the season. These mainly include indoor allergens such as house dust mites and animal dander, as well as allergens found both indoors and outdoors, such as various types of molds.

According to the international ARIA guidelines, the disease is also classified as intermittent or persistent, and as mild or moderate/severe, depending on the extent to which it affects the patient’s daily life.

Impact on Quality of Life & Complications

Allergic rhinitis goes far beyond simply having an “irritated nose.” Difficulty breathing through the nose often forces patients to breathe through their mouth, while impaired breathing during the night can significantly disrupt sleep quality. Poor-quality sleep may result in morning fatigue, reduced concentration during daily activities, and decreased performance at school or work.

In addition, inadequately controlled allergic rhinitis is an important risk factor for:

Allergic Asthma: Inflammation of the upper airways may be associated with inflammation of the lower respiratory tract, resulting in the development or worsening of asthma symptoms.
Rhinosinusitis (Sinusitis): Due to obstruction of the normal drainage pathways of the paranasal sinuses.
Otitis Media with Effusion: Due to dysfunction of the Eustachian tube, a condition particularly common in children.
Nasal Polyps & Sleep Apnea: These may be associated with chronic and recurrent inflammation and persistent nasal obstruction.

Diagnosis & Treatment

Early evaluation by an allergist is essential. Through Skin Prick Testing and a detailed medical history, the responsible allergen can be accurately identified. The treatment strategy is based on three main pillars:

Allergen Avoidance: Implementation of targeted environmental control measures.
Medication: Use of modern, safe antihistamines (tablets or nasal sprays) and intranasal corticosteroids for effective symptom relief.
Allergen-Specific Immunotherapy: The only treatment that targets the underlying allergic mechanism by “training” the immune system to tolerate the responsible allergens. It can provide long-term improvement in allergic rhinitis and may reduce the risk of developing asthma in selected patients.

Early evaluation by an allergist is the first step toward achieving effective control of allergic rhinitis symptoms. Accurate identification of the responsible allergens allows treatment to be tailored appropriately and, when indicated, enables the development of an individualized allergen immunotherapy plan for long-term control of the disease.