Allergic rhinitis (AR) is a prevalent inflammatory disorder of the nasal mucosa, triggered by allergens such as pollen, dust mites, mold, and pet dander. It affects approximately 10–30% of the global population and significantly impacts daily activities, sleep, and overall quality of life (1,2). AR is characterized by nasal congestion, sneezing, rhinorrhea, and itching, often leading to olfactory dysfunction, which further exacerbates the patient’s discomfort (3). The condition is mediated by an immunoglobulin E (IgE)-driven hypersensitivity reaction, leading to the release of inflammatory mediators such as histamine and leukotrienes (4).

Olfactory dysfunction is a common but often overlooked symptom of AR. Inflammation-induced nasal obstruction, mucosal edema, and changes in olfactory receptor sensitivity contribute to impaired odor perception (5). The extent of olfactory impairment varies among individuals and can range from hyposmia (reduced sense of smell) to anosmia (complete loss of smell) (6). Given the integral role of olfaction in taste perception, safety awareness, and overall well-being, its impairment significantly affects quality of life (7).

Medical therapy remains the primary approach to managing AR and its associated symptoms. Intranasal corticosteroids (INS), antihistamines, and leukotriene receptor antagonists (LTRA) are widely used to alleviate nasal inflammation and restore normal function (8). Studies have demonstrated that INS effectively reduce nasal congestion and improve olfaction by decreasing mucosal edema and airway resistance (9). Additionally, oral antihistamines target histamine-mediated symptoms, while LTRAs modulate inflammatory pathways, leading to enhanced symptom control (10). However, the degree of improvement in olfactory function post-treatment remains a subject of interest, necessitating further research.

This study aims to evaluate changes in olfactory function and quality of life in patients with AR following medical therapy. By assessing pre- and post-treatment outcomes, this research seeks to provide valuable insights into the effectiveness of pharmacological interventions in restoring olfactory perception and enhancing patient well-being.

Study Design and Participants

This prospective observational study was conducted at a tertiary care hospital over six months. A total of 100 patients diagnosed with allergic rhinitis (AR) were recruited based on clinical history, symptomatology, and positive skin prick tests or serum-specific IgE levels. Patients aged 18–60 years with persistent or intermittent AR symptoms were included. Individuals with chronic sinusitis, nasal polyps, prior nasal surgeries, or underlying neurological conditions affecting olfaction were excluded.

Intervention and Treatment Protocol

All participants received a standardized medical therapy regimen consisting of intranasal corticosteroids (fluticasone propionate, 100 mcg twice daily), oral antihistamines (levocetirizine, 5 mg once daily), and leukotriene receptor antagonists (montelukast, 10 mg once daily) for four weeks. Patients were instructed on proper nasal spray techniques to ensure optimal drug delivery.

Assessment of Olfactory Function

Olfactory function was evaluated using the Sniffin’ Sticks Test, which assesses odor identification, threshold, and discrimination. Each participant was tested before and after the four-week treatment period. The scores were recorded on a scale of 0 to 16, with higher scores indicating better olfactory function.

Quality of Life Measurement

The impact of AR on quality of life was assessed using the Sino-Nasal Outcome Test-22 (SNOT-22). This questionnaire consists of 22 items covering nasal symptoms, sleep disturbances, and emotional well-being. Each item was rated on a scale from 0 (no problem) to 5 (severe problem). Total scores were recorded pre- and post-treatment, with lower scores indicating improved quality of life.

Statistical Analysis

Data were analyzed using SPSS version 25.0. Paired t-tests were applied to compare pre- and post-treatment olfactory function and quality of life scores. A p-value < 0.05 was considered statistically significant. Descriptive statistics, including mean and standard deviation, were used for data representation.

Demographic Characteristics

A total of 100 patients with allergic rhinitis were included in the study. The mean age of participants was 32.4 ± 8.6 years, with a male-to-female ratio of 55:45. The mean duration of symptoms before treatment initiation was 14.2 ± 4.3 months (Table 1).

Olfactory Function Assessment

Before treatment, the mean Sniffin’ Sticks test score was 8.5 ± 2.3, indicating impaired olfaction. Following four weeks of medical therapy, the mean score significantly improved to 12.7 ± 2.1 (p < 0.001), suggesting enhanced olfactory function (Table 2).

Quality of Life Evaluation

The mean Sino-Nasal Outcome Test-22 (SNOT-22) score before treatment was 42.8 ± 5.6, reflecting substantial impairment in daily activities and well-being. Post-treatment, the mean SNOT-22 score showed a significant reduction to 18.4 ± 4.2 (p < 0.001), indicating notable improvement in quality of life (Table 3).

Table 1: Demographic Characteristics of Study Participants

Table 2: Changes in Olfactory Function (Sniffin’ Sticks Test Scores)

Table 3: Changes in Quality of Life Scores (SNOT-22)

This study demonstrates that medical therapy significantly improves olfactory function and quality of life in patients with allergic rhinitis (AR). The findings align with previous research indicating that inflammation-induced nasal obstruction is a primary contributor to olfactory dysfunction in AR, and its resolution with pharmacological therapy leads to sensory recovery (1,2).

Olfactory dysfunction in AR results from nasal mucosal inflammation, leading to obstruction of airflow to the olfactory cleft and disruption of olfactory receptor neuron signaling (3). The improvement observed in Sniffin’ Sticks test scores post-treatment supports the hypothesis that reducing nasal inflammation restores olfactory perception (4). Similar studies have reported that intranasal corticosteroids (INS) enhance olfaction by decreasing mucosal edema and airway resistance, thereby allowing odorants to reach olfactory receptor sites more effectively (5,6). Furthermore, antihistamines alleviate histamine-induced inflammation, which is known to impair olfactory signaling (7).

The improvement in quality of life, as reflected in the significant reduction in SNOT-22 scores, is consistent with previous studies indicating that AR negatively impacts daily functioning, sleep quality, and mental health (8,9). The decrease in symptoms following treatment highlights the effectiveness of combination therapy with INS, antihistamines, and leukotriene receptor antagonists (LTRA) in providing symptomatic relief (10). Prior research has emphasized that AR is not merely a localized nasal disorder but a systemic inflammatory condition affecting overall well-being (11). Treating nasal inflammation effectively leads to significant improvements in daily activities, work productivity, and social interactions (12).

Despite these promising results, some studies have suggested that olfactory recovery may vary depending on the severity and chronicity of AR. Patients with long-standing nasal obstruction may exhibit delayed or incomplete improvement in olfaction due to irreversible damage to the olfactory epithelium (13). Additionally, individual variations in treatment response have been reported, with some patients showing only partial recovery of olfactory function despite optimal therapy (14). Future research should explore additional therapeutic strategies, including biologics targeting specific inflammatory pathways, to optimize treatment outcomes in refractory cases (15-17).

This study highlights the significant improvement in olfactory function and quality of life in patients with allergic rhinitis following medical therapy. The combination of intranasal corticosteroids, antihistamines, and leukotriene receptor antagonists effectively reduces nasal inflammation, restores olfaction, and alleviates associated symptoms. The findings reinforce the importance of early and sustained pharmacological intervention in managing allergic rhinitis and its impact on daily functioning. Future studies with larger sample sizes and longer follow-up periods are warranted to assess long-term outcomes and explore additional therapeutic options for refractory cases.

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