Allergic rhinitis: When the body reacts to the world around us
Allergic rhinitis is a chronic inflammatory disease of the nasal mucosa. It has a high global prevalence and significantly affects quality of life, work productivity, and daily functioning, while also increasing the risk of comorbid conditions such as asthma and chronic rhinosinusitis.
Keywords: Allergic rhinitis, allergy, type I hypersensitivity, IgE-mediated immunity
What is allergic rhinitis?
Allergic rhinitis is a chronic inflammatory disorder of the nasal mucosa caused by an immunoglobulin E (IgE)–mediated type I hypersensitivity reaction to airborne allergens. It is one of the most common allergic diseases worldwide, affecting approximately 10–30% of the population depending on geographic region, environmental exposure, and genetic background.
Although allergic rhinitis is not life-threatening, it has a substantial impact on quality of life, sleep, learning ability, and work performance, and it increases the risk of comorbid diseases such as asthma, chronic rhinosinusitis, and otitis media with effusion. Therefore, allergic rhinitis is considered an important public health concern.
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Pathophysiology and allergic immune response
The pathophysiology of allergic rhinitis results from a complex immune cascade in individuals who have been sensitized to specific allergens. During the sensitization phase, inhaled allergens are processed by antigen-presenting cells, leading to the activation of T helper type 2 (Th2) lymphocytes. These cells stimulate B lymphocytes to produce allergen-specific IgE antibodies, which subsequently bind to the surface of mast cells and basophils.
Upon re-exposure to the allergen, cross-linking of IgE molecules on mast cells triggers the release of multiple chemical mediators, including histamine, tryptase, leukotrienes, and prostaglandins. The early-phase response is responsible for acute symptoms such as sneezing, nasal itching, and rhinorrhea. This is followed by a late-phase response characterized by the recruitment of eosinophils, T lymphocytes, and pro-inflammatory cytokines (IL-4, IL-5, IL-13), which sustain chronic inflammation and lead to mucosal edema, nasal congestion, and persistent symptoms.
Classification of allergic rhinitis
Allergic rhinitis can be classified based on the timing of allergen exposure and the severity of symptoms. According to temporal patterns, it is divided into seasonal allergic rhinitis, commonly associated with pollen exposure, and perennial allergic rhinitis, typically caused by house dust mites, animal dander, or molds.
Modern classification systems further categorize allergic rhinitis into intermittent or persistent forms, and mild or moderate-to-severe disease, depending on the impact on sleep, daily activities, school performance, and work productivity. This classification is clinically important for guiding treatment strategies and long-term management.
Clinical manifestations and disease characteristics
The clinical presentation of allergic rhinitis is diverse but typically includes four cardinal symptoms: paroxysmal sneezing, watery rhinorrhea, nasal itching, and nasal congestion. Among these, nasal congestion is often the most troublesome symptom, particularly in chronic forms of the disease. Patients frequently experience ocular symptoms such as itching, redness, and tearing due to allergic conjunctivitis.
In children, persistent allergic rhinitis may lead to mouth breathing, sleep disturbances, reduced concentration, and adverse effects on physical and cognitive development. The close association between allergic rhinitis and asthma supports the concept of “one airway, one disease,” emphasizing the importance of controlling upper airway inflammation in the management of lower airway diseases.
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Diagnosis of allergic rhinitis
The diagnosis of allergic rhinitis is primarily clinical, based on a characteristic history of allergen exposure and recurrent symptoms. Physical examination may reveal pale, edematous nasal mucosa with increased clear secretions. Diagnostic tests such as skin prick testing or measurement of serum allergen-specific IgE are useful for identifying causative allergens, particularly in patients with persistent symptoms, poor response to treatment, or when allergen-specific immunotherapy is being considered.
Accurate diagnosis is essential not only for effective management but also for avoiding unnecessary medication use, especially antibiotics.
Treatment of allergic rhinitis
The main goals of allergic rhinitis treatment are symptom control, reduction of nasal inflammation, and improvement of quality of life. Allergen avoidance is a fundamental strategy but is often difficult to achieve completely. Pharmacotherapy remains the cornerstone of management. Intranasal corticosteroids are considered the most effective treatment due to their potent anti-inflammatory effects and their ability to control both early- and late-phase symptoms. Second-generation antihistamines are effective in reducing sneezing, nasal itching, and rhinorrhea, with minimal sedative effects.
Other agents, such as leukotriene receptor antagonists or nasal decongestants, may be used as adjunctive therapy in selected cases. In patients with severe disease or inadequate response to conventional therapy, allergen-specific immunotherapy plays a crucial role in modifying the underlying immune response and reducing long-term disease progression.
Clinical significance and public health impact
Although allergic rhinitis is highly prevalent, it is often underestimated, leading to delayed diagnosis and inadequate treatment. Chronic inflammation of the nasal mucosa not only impairs quality of life but also exacerbates comorbid conditions, particularly asthma and chronic sinusitis.
Therefore, a comprehensive approach to allergic rhinitis—emphasizing long-term management, individualized treatment, and patient education—is essential to reduce disease burden and healthcare costs at the population level.
References:
- Akhouri, S., & House, S. A. (2023). Allergic rhinitis. In StatPearls [Internet]. StatPearls Publishing. National Library of Medicine. https://www.ncbi.nlm.nih.gov/books/NBK538186/
- Skoner, D. P. (2001). Allergic rhinitis: Definition, epidemiology, pathophysiology, detection, and diagnosis. Journal of Allergy and Clinical Immunology, 108(1 Suppl), S2–S8. https://doi.org/10.1067/mai.2001.115569