Persistent allergic rhinitis in children is commonly treated with intranasal corticosteroids (INS), which are considered first-line therapy. However, the delayed onset of action of INS may reduce patient adherence and delay symptom relief. This randomized controlled study evaluates whether adding short-term oxymetazoline nasal spray during the first 5 days of INS treatment ("bridge therapy") improves clinical outcomes, nasal airflow, quality of life, nasal inflammation, and medication adherence in children with persistent allergic rhinitis.

Children aged 4-18 years with moderate-to-severe persistent allergic rhinitis were randomized into two parallel groups. One group received mometasone furoate nasal spray alone for 4 weeks, while the other group received mometasone furoate combined with oxymetazoline during the first 5 days of treatment. Clinical symptoms, Peak Nasal Inspiratory Flow (PNIF), Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ), Nasal Nitric Oxide (nNO), and Medication Adherence Rating Scale (MARS) scores were evaluated.

Allergic rhinitis is one of the most common chronic inflammatory diseases in childhood and significantly affects sleep quality, school performance, daily functioning, and quality of life. Intranasal corticosteroids (INS) are recommended as first-line therapy because of their strong anti-inflammatory effects. However, the onset of symptom relief may take several days or weeks, especially in patients with severe nasal congestion. This delayed onset may negatively affect treatment adherence and early treatment satisfaction.

Short-term use of topical nasal decongestants may provide rapid nasal patency and facilitate delivery of intranasal corticosteroids into the nasal cavity. This study investigates whether short-term oxymetazoline therapy added to the initiation of INS treatment can function as a "bridge therapy" in children with persistent allergic rhinitis.

This prospective randomized controlled study enrolled children aged 4-18 years diagnosed with moderate-to-severe persistent allergic rhinitis according to ARIA guidelines. Participants were randomized into two parallel treatment groups:

1. Intranasal corticosteroid monotherapy group (mometasone furoate for 4 weeks)
2. Combination therapy group (mometasone furoate for 4 weeks plus oxymetazoline during the first 5 days)

Clinical symptom severity was assessed using Total Nasal Symptom Score (TNSS). Objective nasal airflow was evaluated with Peak Nasal Inspiratory Flow (PNIF). Nasal inflammation was assessed using Nasal Nitric Oxide (nNO). Disease-specific quality of life was measured using the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ), and treatment adherence was evaluated using the Medication Adherence Rating Scale (MARS).

The primary objective of the study is to determine whether bridge therapy improves symptom control compared with intranasal corticosteroid monotherapy. Secondary objectives include evaluating effects on nasal airflow, quality of life, nasal inflammation, and medication adherence.

Inclusion Criteria:

• Children aged 4 to 18 years
• Diagnosis of moderate-to-severe persistent allergic rhinitis according to ARIA guidelines
• Ability to comply with study procedures
• Written informed consent obtained from parents or legal guardians

Exclusion Criteria:

• Mechanical nasal obstruction (nasal polyposis, severe septal deviation, or adenoid hypertrophy)
• Acute upper respiratory tract infection within the previous 2 weeks
• Active smoking or significant passive smoke exposure
• Current use of allergic rhinitis medications
• Use of intranasal corticosteroids within the previous 3 months
• Inability to comply with study procedures

Individual participant data (IPD) will not be publicly shared due to institutional policies and protection of participant confidentiality.

Blinding was not feasible because the immediate vasoconstrictive effect of oxymetazoline is clinically perceptible.