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The “caterpillar sign”: a novel endoscopic indicator of eosinophilic esophagitis

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Although several endoscopic findings of eosinophilic esophagitis (EoE), such as the EoE endoscopic reference score (EREFS), have been reported thus far, these endoscopic findings exhibit low specificity. Furthermore, most of these endoscopic findings were evaluated solely in patients from Western nations. We have recently noted a fragile, protruded mucosal lesion sandwiched between longitudinal furrows (similar to caterpillar tracks) on the esophagus in patients with EoE. We have termed this novel finding the “caterpillar sign”. This study evaluated the clinical significance of the caterpillar sign and the EREFS for diagnosis of EoE in Japanese patients.


We retrospectively analyzed endoscopic images from 165 consecutive patients who underwent tissue collection on suspicion of EoE. We compared the clinical significance between the EREFS and the caterpillar sign. We defined EoE as the presence of ≥ 15 eosinophils on esophageal mucosa per high-power field; control images had < 15 eosinophils per high-power field. For evaluation of endoscopic diagnosis capacity using the total EREFS, 2 points was set as the cutoff value. The presence or absence of the caterpillar sign was evaluated.


The sensitivity, specificity, positive predictive value, and negative predictive value of total EREFS ≥ 2 for the diagnosis of EoE were 100%, 56.2%, 56.6%, and 100%; for the caterpillar sign, those values were 83.3%, 98.1%, 96.2%, and 91.2%, respectively. Interobserver agreement for identification of the caterpillar sign was substantial (κ = 0.80)


The caterpillar sign could be a novel reliable indicator for endoscopic diagnosis of EoE.

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  1. Dellon ES. Epidemiology of eosinophilic esophagitis. Gastroenterol Clin North Am. 2014;43:201–18 (PubMed: 4019938).

    Article  Google Scholar 

  2. Jensen ET, Kappelman MD, Martin CF, et al. Health-care utilization, costs, and the burden of disease related to eosinophilic esophagitis in the United States. Am J Gastroenterol. 2015;110:626–32 (PubMed: 4590991).

    Article  Google Scholar 

  3. Furuta K, Adachi K, Kowari K, et al. A Japanese case of eosinophilic esophagitis. J Gastroenterol. 2006;41:706–10.

    Article  Google Scholar 

  4. Shimura S, Ishimura N, Tanimura T, et al. Reliability of symptoms and endoscopic findings for diagnosis of esophageal eosinophilia in a Japanese population. Digestion. 2014;90:49–57 (PubMed: 25170629).

    Article  Google Scholar 

  5. Sato H, Honma T, Nozawa Y, et al. Eosinophilic esophagitis in Japanese patients: a mild and slow-progressing disorder. PLoS ONE. 2018;13:e0206621 (PubMed: 30388148).

    Article  Google Scholar 

  6. Imamura K, Haruma K, Matsumoto H, et al. Clinical and endoscopic characteristics of eosinophilic esophagitis in Japan: a case-control study. Asia Pac Allergy. 2020;10:e16 (PubMed: 32411581).

    Article  Google Scholar 

  7. Dellon ES, Liacouras CA. Advances in clinical management of eosinophilic esophagitis. Gastroenterology. 2014;147:1238–54 (PubMed: 25109885).

    Article  Google Scholar 

  8. Peery AF, Cao H, Dominik R, et al. Variable reliability of endoscopic findings with white-light and narrow-band imaging for patients with suspected eosinophilic esophagitis. Clin Gastroenterol Hepatol. 2011;9:475–80 (PubMed: 21377547).

    Article  Google Scholar 

  9. Kim HP, Vance RB, Shaheen NJ, et al. The prevalence and diagnostic utility of endoscopic features of eosinophilic esophagitis: a meta-analysis. Clin Gastroenterol Hepatol. 2012;10(988–96):e5 (PubMed: 22610003).

    Google Scholar 

  10. Fujiwara Y, Tanigawa T, Yamagami H, et al. Eosinophilic esophagitis-like endoscopic findings in patients with erosive esophagitis. Esophagus. 2013;10:199–204.

    Article  Google Scholar 

  11. Hirano I, Moy N, Heckman MG, et al. Endoscopic assessment of the oesophageal features of eosinophilic oesophagitis: validation of a novel classification and grading system. Gut. 2013;62:489–95 (PubMed: 22619364).

    Article  Google Scholar 

  12. Dellon ES, Cotton CC, Gebhart JH, et al. Accuracy of the eosinophilic esophagitis endoscopic reference score in diagnosis and determining response to treatment. Clin Gastroenterol Hepatol. 2016;14:31–9 (PubMed: 26404868).

    Article  Google Scholar 

  13. van Rhijn BD, Verheij J, Smout AJ, et al. The endoscopic reference score shows modest accuracy to predict histologic remission in adult patients with eosinophilic esophagitis. Neurogastroenterol Motil. 2016;28:1714–22 (PubMed: 27254480).

    Article  Google Scholar 

  14. Rodriguez-Sanchez J, Barrio-Andres J, Nantes Castillejo O, et al. The endoscopic reference score shows modest accuracy to predict either clinical or histological activity in adult patients with eosinophilic oesophagitis. Aliment Pharmacol Ther. 2017;45:300–9 (PubMed: 27868216).

    Article  CAS  Google Scholar 

  15. Dellon ES, Gonsalves N, Hirano I, et al. ACG Clinical Guideline: evidence based approach to the diagnosis and management of esophageal eosinophilia and eosinophilic esophagitis. Am J Gastroenterol. 2013;108:679–92 (PubMed: 23567357).

    Article  Google Scholar 

  16. Liacouras CA, Furuta GT, Hirano I, et al. Eosinophilic esophagitis: updated consensus recommendations for children and adults. J Allergy Clin Immunol. 2011;128(3–20):e6 (PubMed: 21477849).

    Google Scholar 

  17. Manabe N, Yoshihara M, Sasaki A, et al. Clinical characteristics and natural history of patients with low-grade reflux esophagitis. J Gastroenterol Hepatol. 2002;17:949–54 (PubMed: 12167114).

    Article  Google Scholar 

  18. Kimura K, Takemoto T. An endoscopic recognition of the atrophic border and its significance in chronic gastritis. Endoscopy. 1969;1:87–97.

    Article  Google Scholar 

  19. Saffari H, Peterson KA, Fang JC, et al. Patchy eosinophil distributions in an esophagectomy specimen from a patient with eosinophilic esophagitis: implications for endoscopic biopsy. J Allergy Clin Immunol. 2012;130:798–800 (PubMed: 22502795).

    Article  Google Scholar 

  20. Collins MH. Histopathologic features of eosinophilic esophagitis. Gastrointest Endosc Clin N Am. 2008;18:59–71, viii–ix (PubMed: 18061102).

  21. Furuta GT, Liacouras CA, Collins MH, et al. Eosinophilic esophagitis in children and adults: a systematic review and consensus recommendations for diagnosis and treatment. Gastroenterology. 2007;133:1342–63 (PubMed: 17919504).

    Article  CAS  Google Scholar 

  22. Chen JW, Pandolfino JE, Lin Z, et al. Severity of endoscopically identified esophageal rings correlates with reduced esophageal distensibility in eosinophilic esophagitis. Endoscopy. 2016;48:794–801 (PubMed: 27200524).

    Article  Google Scholar 

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We thank Ryan Chastain-Gross, Ph.D., from Edanz Group ( for editing a draft of this manuscript. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

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Authors and Affiliations



All authors contributed to the study conception and design. Material preparation, data collection, and analysis were performed by MA, NM, JN, MF, TK, KI, KI, and KH. The first draft of the manuscript was written by MA and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

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Correspondence to Noriaki Manabe.

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Ethical Statement

All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions.

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Maki Ayaki, Noriaki Manabe, Jun Nakamura, Minoru Fujita, Tomoari Kamada Kazumi Imamura, Kazuhiko Inoue, and Ken Haruma declare that they have no conflict of interest.

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Informed consent or substitute for it was obtained from all patients for being included in the study.

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Ayaki, M., Manabe, N., Nakamura, J. et al. The “caterpillar sign”: a novel endoscopic indicator of eosinophilic esophagitis. Esophagus 18, 156–162 (2021).

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