Nasal eosinophilia and responsiveness to local steroids hallmark of non-allergic rhinitis

Greece: A recent study published in the European Archives of Oto-Rhino-Laryngology has concluded that the presence of nasal Eosinophils > 20% and continuous response to nasal steroid therapy indicates Atopia in children with Non-Allergic Rhinitis (NAR) symptoms. The researchers added that nasal eosinophilia is a biomarker of NAR and is suggestive of further investigation, such as NAPT, to distinguish Local Allergic Rhinitis (LAR) from non-allergic rhinitis with eosinophilia syndrome (NARES).

NAR in children, named local allergic rhinitis (LAR) and non-allergic rhinitis with eosinophilia syndrome (NARES), is characterized by symptoms suggestive of allergic rhinitis in the absence of systemic atopy. The principal cells involved in allergy inflammation are Nasal eosinophils (nEo). The standard diagnostic method is the nasal allergen provocation test, but it has limitations. There is a need to distinguish NAR from NARES.

Considering this, a study was conducted by Athina Papadopoulou from the Pediatric Allergy and Asthma Unit at KAT General Hospital to determine if nEo and therapeutic response to nasal steroids combination could be validated or not to preliminary distinguish NAR from NARES in real-life data.

The key points of the study are:

• The study enrolled 128 children, including 63.3% of males with a NAR history.

• The participants were followed up for 52 ± 32 m.

• Nasal cytology was performed at baseline to non-atopic children.

• The symptoms of allergic rhinitis were present for more than eight weeks.

• The nasal steroids were given for 20 days.

• 10-VAS clinically evaluated response to therapy.

• In relapsing symptoms and nEo, the same therapeutics was repeated.

• During the follow-up period, those cases which were constantly responding to nasal steroids proceeded for NAPT intending to distinguish LAR from NARES.

• Significant nasal Eosinophils were reported in 59.3% of the cases, and there was an association with reported dyspnea episodes.

• 23.4% did not respond to therapy.

• 51.5% of children constantly responded to treatment.

• Response to therapy was related to nasal eosinophils.

• The cut-off point was 20%.

Researchers reported nasal eosinophils as the most reliable biological marker and had a sensitivity of 94 % and specificity of 77 %.

The co-researcher, Stavroula Lambidi from the Pediatric Allergy and Asthma Unit at KAT General Hospital, said nasal eosinophilia > 20% constantly responding to nasal steroid therapy in children with symptoms of NAR indicates atopy.

In everyday clinical practice, this is an easy, preliminary cell biomarker and suggests further investigation for NAPT, and it also discriminates LAR from NARES.

Further reading:

Papadopoulou, A., Lambidi, S., Lagousi, T. et al. Nasal eosinophilia as a preliminary discriminative biomarker of non-allergic rhinitis in everyday clinical pediatric practice. Eur Arch Otorhinolaryngol (2022). https://doi.org/10.1007/s00405-022-07704-0