Background: Because young children cannot self-report symptoms, there is a need for parent surrogate reports. Although early work suggested parent-child alignment for eosinophil esophagitis (EoE) patient-reported outcomes (PROs), the longitudinal alignment is unclear., Objective: We sought to assess the agreement and longitudinal stability of PROs between children with EoE and their parents., Methods: A total of 292 parent-child respondents completed 723 questionnaires over 5 years in an observational trial in the Consortium of Eosinophilic Gastrointestinal Disease Researchers. The change in and agreement between parent and child Pediatric Eosinophilic Esophagitis Symptom Score version 2 (PEESSv2.0) and Pediatric Quality of Life Eosinophilic Esophagitis Module (PedsQL-EoE) PROs over time were assessed using Pearson correlation and Bland-Altman analyses. Clinical factors influencing PROs and their agreement were evaluated using linear mixed models., Results: The cohort had a median disease duration equaling 3.7 years and was predominantly male (73.6%) and White (85.3%). Child and parent PEESSv2.0 response groups were identified and were stable over time. There was strong correlation between child and parent reports (PEESSv2.0, 0.83;PedsQL-EoE, 0.74), with minimal pairwise differences for symptoms. Longitudinally, parent-reported PedsQL-EoE scores were stable (P ≥ .32), whereas child-reported PedsQL-EoE scores improved (P = .026). A larger difference in parent and child PedsQL-EoE reports was associated with younger age (P < .001), and differences were driven by psychosocial PRO domains., Conclusions: There is strong longitudinal alignment between child and parent reports using EoE PROs. These data provide evidence that parent report is a stable proxy for objective EoE symptoms in their children., Competing Interests: Disclosure statement CEGIR (U54 AI117804) is part of the Rare Disease Clinical Research Network, an initiative of the Office of Rare Diseases Research, National Center for Advancing Translational Sciences (NCATS), and is funded through a collaboration between NIAID, the National Institute of Diabetes and Digestive and Kidney Diseases, and NCATS and funded in part by the Division of Intramural Research, NIAID. CEGIR is also supported by patient advocacy groups including the American Partnership for Eosinophilic Disorders, Campaign Urging Research for Eosinophilic Diseases, and Eosinophilic Family Coalition. As a member of the Rare Disease Clinical Research Network, CEGIR is supported by its Data Management and Coordinating Center (grant no. U2CTR002818). Funding support for the Data Management and Coordinating Center is provided by NCATS and the National Institute of Neurological Disorders and Stroke. G.S.H. is supported by a grant from the National Institutes of Health (NIH) (grant no. K23 DK131341). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. Disclosure of potential conflict of interest: M. E. Rothenberg is a consultant for Pulm One, Spoon Guru, ClostraBio, Serpin Pharm, Allakos, Celldex, Nexstone One, Santa Ana Bio, EnZen Therapeutics, Bristol Myers Squibb, AstraZeneca, Pfizer, GlaxoSmithKline, Regeneron/Sanofi, Revolo Biotherapeutics, and Guidepoint and has an equity interest in the first 9 listed; receives royalties from Teva Pharmaceuticals (reslizumab), Mapi Research Trust (PEESSv2.0), and UpToDate; and is an inventor of patents owned by Cincinnati Children’s Hospital. J. M. Spergel is a consultant for ReadySetfood, Regeneron/Sanofi, and ARS Pharma; has grant support from Novartis, Regeneron/Sanofi, Bristol Myers Squibb, Food Allergy Research and Education (FARE), and NIH; receives royalties from UpToDate; and serves on the Data Safety and Monitoring Board for Alladapt and NIAID. M. H. Collins is a consultant for Allakos, Arena/Pfizer, AstraZeneca, Calypso Biotech, EsoCap Biotech, GlaxoSmithKline, Receptos/Celgene/Bristol Myers Squibb, Regeneron Pharmaceuticals, Robarts Clinical Trials, Inc/Alimentiv, Inc, and Shire/Takeda. S. S Aceves is a consultant and an educational speaker for Regeneron/Sanofi; has grant support from the NIH, Campaign Urging Research for Eosinophilic Diseases, Bristol Myers Squibb, and Implicit Biosciences; and is a coinventor of oral viscous budesonide patented by the University of California San Diego and licensed by Takeda. M. Pletneva is a consultant for Allakos. S. K. Gupta is a consultant and/or Data Safety and Monitoring Board member for Adare, Bristol Myers Squibb, QOL, Takeda, Medscape, PVI, ViaSkin, and UpToDate; and receives research support from Allakos, Ellodi, and AstraZeneca. J. B. Wechsler is a consultant for Bristol Myers Squibb, Ellodi, AstraZeneca, Allakos, and Regeneron/Sanofi; and receives research support from Regeneron. N. Gonsalves is a consultant for AstraZeneca, Allakos, Sanofi/Regeneron, AbbVie, Knopp, and Bristol Myers Squibb; is on the speaker bureau for Sanofi/Regeneron; and receives publication royalties from UpToDate. G. W. Falk is a consultant for Allakos, Bristol Myers Squibb/Celgene, Adare/Ellodi, Nexstone, Upstream Bio, and Sanofi/Regeneron; and receives research support from Allakos, Adare/Ellodi, Bristol Myers Squibb/Celgene, and Regeneron/Sanofi. I. Hirano has received research funding from Adare Pharmaceuticals/Ellodi Pharmaceuticals, Allakos, AstraZeneca, Meritage Pharma, Inc, Receptos/Celgene/Bristol Myers Squibb, Regeneron Pharmaceuticals, and Shire/Takeda; and is a consultant for Adare Pharmaceuticals/Ellodi Pharmaceuticals, Allakos, Arena Pharmaceuticals, Aslan Pharmaceuticals, AstraZeneca, Calyx/Parexel, Celldex Therapeutics, Inc, Dermavant, EsoCap Biotech, Gossamer Bio, Eli Lilly, Nexstone, Meritage Pharma, Inc, Phathom Pharmaceuticals, Receptos/Celgene/Bristol Myers Squibb, Sanofi/Regeneron Pharmaceuticals, and Shire/Takeda. M. Chehade has received consultant fees from Regeneron, Adare/Ellodi, AstraZeneca, Sanofi, Bristol Myers Squibb, Recludix Pharma, Allakos, Shire/Takeda, and Phathom; and has received research support from Regeneron, Allakos, Shire/Takeda, AstraZeneca, Adare/Ellodi, and Danone. C. M. Davis has received grant funding from DBV Technologies, Aimmune Therapeutics, Regeneron Pharmaceuticals, and Allergenis. E. S. Dellon is a consultant for Abbott, AbbVie, Adare/Ellodi, Aimmune, Akesobio, Alfasigma, ALK, Allakos, Amgen, Aqilion, Arena/Pfizer, Aslan, AstraZeneca, Avir, Biorasi, Calypso, Celgene/Receptos/Bristol Myers Squibb, Celldex, Eli Lilly, EsoCap, Eupraxia, Ferring, GlaxoSmithKline, Gossamer Bio, Holoclara, Invea, Knightpoint, Landos, LucidDx, Morphic, Nexstone Immunology, Nutricia, Parexel/Calyx, Phathom, Regeneron, Revolo, Robarts/Alimentiv, Salix, Sanofi, Shire/Takeda, Target RWE, and Upstream Bio; has received research funding from Adare/Ellodi, Allakos, Arena/Pfizer, AstraZeneca, GlaxoSmithKline, Meritage, Miraca, Nutricia, Celgene/Receptos/Bristol Myers Squibb, Regeneron, Revolo, and Shire/Takeda; and has received an educational grant from Allakos, Aqilion, Holoclara, and Invea. G. T. Furuta is Chief Medical Officer for EnteroTrack; and receives research funding from Arena/Pfizer. The rest of the authors declare that they have no relevant conflicts of interest., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. All rights reserved.)