Sinusitis and Olfaction Improve in Young Children with Cystic Fibrosis Treated with ETI.

OBJECTIVES

Evaluate if early therapeutic initiation may begin ameliorating olfactory dysfunction in addition to chronic rhinosinusitis in young children with cystic fibrosis.

METHODS

Participants ≤ 10 years were enrolled across six U.S. cystic fibrosis centers (May 2023-December 2024). Data were collected at baseline and one year following therapeutic initiation. Mixed-effects models were adjusted for age, sex, and nasal steroid use.

MEASUREMENTS: Sinus magnetic resonance imaging analysis included sinus volume, sinus opacification, olfactory bulb volume, olfactory cleft opacification, Lund-Mackay, and CRS-MRI scores. Psychophysical olfactory testing and quality of life assessments included the Pediatric Smell Wheel, Brief Questionnaire of Olfactory Disorders, EuroQol-5-Dimensions-Youth, and Sinonasal-5.Main

Results

31 participants (mean age 4.8 years) enrolled, 27 initiated treatment, and 26 completed follow-up (mean treatment duration 1.0 years). Following therapy, three olfactory measures improved: odor identification scores increased by 1.3 points (p = 0.03), olfactory bulb volume increased by 7.4mm3 (p = 0.02), and olfactory cleft opacification decreased by 14.4% (p = 0.004). Sinus opacification, Lund-Mackay, and CRS-MRI scores improved by 25.5% (p = 0.001), 5.0 points (p = 0.002) and 7.0 points (p = 0.005), respectively. Quality of life scores remained at near-normal levels.

CONCLUSIONS

Children receiving therapy demonstrated improvements in olfactory function, olfactory structure, and sinonasal opacification. Predominantly stable, near-normal quality of life metrics preliminarily suggest symptom-based instruments alone may be insufficient to identify sinonasal disease and treatment response at this age.