Allergic Rhinitis and Recurrent Respiratory Infections: Two Therapeutic Goals

Video: frequent respiratory infections in children

Professor Oleksandr Bredun: “Frequent respiratory infections in a child. What should a pediatrician and an ENT doctor check?” (video in Ukrainian)

How viral infection affects allergy, and vice versa

Viral infections can trigger exacerbations of allergic airway diseases by activating the epithelial and innate immune response. On the other hand, Th2-associated inflammation may weaken local antiviral mechanisms. In an experimental study by Contoli et al., the nasal epithelium of patients with atopic rhinitis showed increased IL-4 expression, reduced TLR3 expression and increased replication of rhinovirus RV-16 compared with participants without atopic symptoms [1]. This does not prove that all patients with AR have more frequent or more severe viral infections, but it shows that there are aspects that need further research.

Clinical observations: from rhinovirus to environmental factors

In a study of children with AR, rhinovirus was detected in about 40% of them. In the subgroup that did not receive allergen-specific immunotherapy, there was a direct correlation between the presence of rhinovirus and the severity of AR symptoms on a visual analogue scale [2]. In a separate questionnaire study of 387 respondents, upper respiratory tract infections, adenoid hypertrophy and adverse environmental factors showed positive statistical associations with AR [3]. Both studies support a comprehensive assessment of the patient, but neither proves causality or the effectiveness of a specific treatment regimen.

Controlling allergic inflammation: the role of intranasal corticosteroids

The updated ARIA–EAACI 2024–2025 recommendations consider intranasal corticosteroids (INCS) one of the cornerstones of AR treatment: their use compared with no treatment carries a strong recommendation. When monotherapy is chosen, INCS are conditionally suggested over intranasal antihistamines, taking into account individual symptoms, patient preferences, availability and cost [4].

Flix: mometasone furoate in the treatment of allergic rhinitis

Flix is an intranasal mometasone furoate product belonging to the INCS class. Its place in the management of AR is defined by the anti-inflammatory action of mometasone and the general principles of INCS selection. Flix is used for AR in adults and children from 3 years of age. Age indications, dosing and contraindications should be determined according to the current product information. Important: ARIA does not establish superiority of mometasone over all other INCS, and there is insufficient information on the advantages of any specific INCS in children [4].

A different goal: preventing recurrent respiratory infections

Even with good control of allergic rhinitis, some patients may still have frequent respiratory infections. Doctors should separately assess their frequency, severity, risk factors, adenoid status, comorbidities, vaccination status and the need for preventive measures. AR treatment on its own is not a proven strategy for preventing acute respiratory infections.

Broncho-Vaxom (OM-85): mucosal immunomodulation

Broncho-Vaxom contains OM-85, a standardized bacterial lysate. According to preclinical studies, OM-85 modulates the innate and adaptive immune response, including processes involving dendritic cells, macrophages and IgA-associated mucosal defense [5]. Cell models have also described an effect of OM-85 on type I interferons, but these results are not direct evidence of clinical antiviral efficacy [6, 7].

What do clinical studies of bacterial lysates show?

A systematic review and meta-analysis by Li et al. pooled 19 randomized trials involving 1728 patients with various allergic diseases; 17 of the trials used OM-85. Overall, the likelihood of improved control of allergic symptoms was higher in the bacterial lysate groups (RR 1.24; 95% CI 1.19–1.30). The authors found a threefold greater improvement in patients with AR who received a bacterial lysate in addition to their main therapy. However, these data do not support registering OM-85 for the treatment of AR and do not replace basic anti-allergic therapy [8].

Broncho-Vaxom in clinical practice: correct positioning

Prescribing Broncho-Vaxom should be linked primarily to the prevention of recurrent respiratory tract infections in line with the current product information, and it should not be presented as a standard treatment for allergic rhinitis. Data on immune mechanisms and possible effects on allergic manifestations are of additional scientific interest, but they do not prove that the product prevents all viral infections or that it should be prescribed to every patient with AR. Before prescribing, approved age limits, dosing regimens and warnings should be checked.

Two therapeutic goals, one personalized approach

For a patient with allergic rhinitis and frequent respiratory episodes, it makes sense to separate two approaches. The first is to control allergic inflammation with recommended agents, including INCS (Flix in suitable patients). The second is to assess the need to prevent recurrent infections, including the possible use of OM-85 (Broncho-Vaxom) according to its approved indications. This distinction is consistent with individualized therapy and does not imply automatic co-prescription of the two products.

Conclusions

Allergy and viral infections can influence each other, but the level of evidence for different mechanisms varies. The priority in AR is adequate control of inflammation and symptoms according to ARIA–EAACI. Recurrent respiratory tract infections require a separate assessment of risks and prevention options. Flix and Broncho-Vaxom serve different therapeutic goals and may only be used in accordance with the current product information.