A novel endoscopic finding of a scratch sign is useful for evaluating the Helicobacter pylori infection status

Abstract

Objectives During esophagogastroduodenoscopy, a red linear scrape‐like appearance with white deposits sometimes appears on the gastric mucosa at the lower greater curvature of the gastric body, a finding we named the “scratch sign.” We aimed to clarify the clinical significance of this new endoscopic finding in the endoscopic evaluation of the Helicobacter pylori infection status. Methods Among patients who underwent esophagogastroduodenoscopy at our hospital between October 2016 and June 2017, 437 patients were included in the study. We first examined the overall scratch sign positivity rate, and then this was compared according to the H. pylori infection status. Subsequently, other variables were compared and examined between the positive and negative scratch sign groups. Results Overall, 437 patients were included in the analysis. The scratch sign was observed in 1.4% of 71 patients with current infections, 26.9% of 290 patients with past infections, and 31.6% of 76 uninfected patients. In the multivariate analysis, H. pylori ‐negative, severe gastric mucosal atrophy, and acid secretion depressant were independent factors that significantly affected the appearance of the scratch sign. Conclusions A novel endoscopic finding, the scratch sign, was found to be a good endoscopic predictor of H. pylori ‐negative gastric mucosa. Furthermore, combined with atrophic changes and xanthomas that persisted after eradication, these findings were found to be useful in accurately diagnosing H. pylori past‐infected gastric mucosa endoscopically.

Validation of a Novel Endoscopic Feature that Predicts Helicobacter pylori-negative Status: Does the Scratch Sign Reflect H. pylori Non-infection?

“…In a previous study, the scratch sign had a high specificity and positive predictive value for indicating H. pylori-negative status, as only one patient was infected in the group with the scratch sign. 9 However, in our study, we found the number of 24 patients with current infections had scratch sign (Table 2) and patients with scratch sign had significantly lower rate of sticky mucus (0.7% vs. 20.4%, P<0.001). These findings were also shown in multivariate analysis, which found the only sticky mucus was significantly lowered the risk of scratch sign (Table 5).…”

“…Yada et al 9 previously reported a significant association between a negative scratch sign and higher degrees of mucosal lesions, such as atrophy, intestinal metaplasia, enlarged folds, and diffuse redness, which all contribute to the Kyoto score. In our study, we also observed significant differences in the Kyoto score between patients with and without the scratch sign (1.7 vs. 3.3, P<0.001), reflecting similar findings.…”

“…A previous study suggested that this is related to the presence of a mucus layer. 9 In mucosa not infected by H. pylori, the mucus gel layer is preserved. However, when severe atrophy and intestinal metaplasia occur due to infection or when acid suppression medications such as PPIs or PCABs are taken, the mucus gel layer diminishes.…”

“…While previous study has showed significant differences in gender and medication use between patients with and without the scratch sign, our study showed that there was no significant characteristics between the groups (Supplementary Table 1). 9 In our study, we used RUT to evaluate H. pylori status, so we excluded the patients taking acid suppression medication (PPI, PCAB, and H2 blocker) to rule out false negative result. Therefore, it would be needed to analyze the association between the medication and endoscopic findings in the further study.…”

“…While observing the duodenum, the shaft of the endoscope passes over the greater curvature of the stomach and may cause a red linear scrape-like appearance with white deposit, which was named as "scratch sign" in a recent study. 9 The scratch sign is thought to occur due to mechanical stimulation related to the pressure of the scope and although this scratch sign is often seen in clinical practice, endoscopists have not attached any special significance to it. However, the study suggested that the scratch sign might be a good endoscopic predictor of H. pylori-negative gastric mucosa and found it to be useful in endoscopically diagnosing previously infected gastric mucosa when combined with atrophic changes and xanthomas that persisted after eradication of H. pylori.…”