Acute rhinitis is an inflammatory process that primarily affects the nasal mucosa, with a high incidence in the pediatric population and a morbidity rate of 6-8 episodes annually during the first two years of schooling (1). It is one of the most common conditions causing discomfort and debilitation in children, compromising their quality of life, negatively affecting social interactions, school performance, and sleep quality. In most cases, the origin is viral and the course is seasonal, with higher incidence in the autumn and winter seasons (1).

More than 100 viral strains are known to be responsible for this condition, among which Rhinoviruses are considered the most widespread and contagious (2). Symptoms, which typically begin 1-2 days after infection, include nasal congestion, nasal breathing obstruction, rhinorrhea, sneezing, coughing, headache, malaise, and sometimes mild fever, with complete remission generally occurring within 8-10 days (2).

The therapeutic approach is exclusively symptomatic, mainly aimed at reducing nasal obstruction. Literature indicates that nasal irrigation with saline solution is the most useful treatment for cleansing the nasal passages, thinning nasal secretions, and allowing for easier elimination; in the presence of fever, antipyretics may be useful (3).

Given these premises, the aim of this clinical study was to evaluate the therapeutic efficacy of an isotonic saline solution containing mullein, thyme, propolis, and long-chain polyphosphates, which are known for their natural properties to promote nasal secretion fluidity, reduce inflammation, and improve the functionality of the upper respiratory mucosa (4). In addition, more recent pre-clinical data suggested that this formulation exerts an antiviral action characterized by inhibition of virus replication (Rhinovirus and SARS-CoV-2) and an anti-inflammatory action through modulation of NF-Kb signaling in cultured human nasal respiratory epithelial cells. These effects are also associated with antibacterial action thanks to mullein and thyme.

Inclusion Criteria:

• Caucasian subjects of both sexes,
• aged between 4 and 14 years;
• diagnosis of acute rhinitis based on the presence of ≥3 of the following symptoms that had onset within the last 24 hours: rhinorrhea, nasal congestion, nasal obstruction, sneezing, pharyngodynia, cough;
• in addition to ≥1 of the following signs/symptoms: headache;
• fever; malaise; burning eyes; myalgia;
• written informed consent obtained from the parents of the participants and from the participants themselves if older than 6 years.

Exclusion Criteria:

• non-Caucasian ethnicity; age <4 and >14 years; known hypersensitivity/allergy to any component of the dietary supplement;
• previous diagnosis of severe nasal septal deviation or any other condition that could cause nasal obstruction, such as nasal polyps;
• history of nasal or sinus surgery that could affect symptom scores; use of antibiotics, corticosteroids, or antihistamines within 2 weeks prior to the study; participation in other studies;
• conditions that made compliance with the protocol unlikely.