{'fraction_non_alphanumeric': 0.028519046649012017, 'fraction_numerical': 0.00916683642289672, 'mean_word_length': 5.061728395061729, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Towards Better Diagnosis and Monitoring of Eosinophilic Esophagitis.

E osinophilic Esophagitis (EoE) appeared on the medical radar in the 1980s. Before that time EoE was probably misdiagnosed as reflux esophagitis. Lee et al (1) reanalyzed historic esophageal biopsy specimens and found no change in the percentage of biopsies that fit criteria for EoE between 1980 and 2000. Since then EoE has been recognized as a non-IgE-mediated immune disorder characterized by esophageal dysfunction and esophageal biopsies with greater than 15 eosinophils per high power field (2). EoE has a number of disease phenotypes. Young children present with vomiting, regurgitation, and feeding difficulty, whereas older children and adolescents have dysphagia, food impaction, and stricture (3). It is believed that EoE is a lifelong, relapsing condition, although the natural history of the condition and especially of its various phenotypes is poorly understood. EoE responds to either steroid therapy (usually topical) or antigen elimination. As symptoms correlate poorly with condition activity (4), at the present time, endoscopy with biopsies is the preferred method of diagnosis and monitoring. According to present recommendations, the diagnosis of EoE requires a minimum of 2, but usually 3 endoscopies 8 weeks apart (5). If treatment with topical steroids is selected, monitoring usually involves esophageal biopsies every 6 to 12 months. Other treatment protocols entail even more procedures. Implementing the classic 6 food elimination diet, including the endoscopies for diagnosis, requires 10 endoscopies over 20 months (there are protocols that shorten this process). We are clearly badly in need of more complete information about the disease and less arduous ways of diagnosing and monitor EoE. Elsewhere in this issue of the Journal, Lowry et al offer a possible way to simplify managing EoE. They present data using a new technique of mucosal impedance (MI). This technique must be clearly distinguished from the more widely recognized multichannel intraluminal impedance (MII). Although MII is widely used to evaluate gastroesophageal reflux, MII has been less helpful to assess the inflammatory changes at the mucosal level. MI was developed to investigate effects of inflammation at the mucosal level. Instead of the 7 sensors of MII spaced along a esophageal catheter, MI has just 2 sensors spaced close together (each sensor is 3 mm in length and the 2 sensors are placed 2 mm from each other). As opposed to the MII procedure where the esophageal catheter is placed into the lumen of the esophagus and remains in place, in this study, the MI catheter was introduced through an endoscope and applied to the esophageal mucosa. Impedance readings were taken and then the sensors were moved to another reading point. In this study, impedance was measured at 2 cm, 5 cm, and 10 cm above the z-line. Using this technique, the investigators were able to distinguish among active EoE, inactive EoE, nonerosive reflux disease (NERD), and controls. The investigators also report significant inverse relationship between impedance and number of eosinophils per high power field. The ability of the MI technique to identify degrees of EoE, NERD, and controls is impressive, however, the real importance of this technique is the possibility that, with the next iteration of MI, it might avoid an endoscopy. To perform the MI technique without endoscopy would require accurate placement of the sensors and assurance that the sensors were abutted against the esophageal mucosa. Big, but not impossible, hurdles to overcome. Meanwhile there are ongoing efforts to reduce the negative effects of multiple endoscopies and multiple anesthesias. Nasal endoscopy is already being used in some centers (6). Nasal endoscopy is restricted to the older child and adolescent, but is done with local anesthetic and mild conscious sedation. Results are comparable with routine endoscopy with biopsies (Raza Patel, personal communication). There have also been nonendoscopic attempts at diagnosing and monitoring. Furuta et al (7) reported on the ‘‘string test’’ and Katzka et al (8) described a ‘‘cytosponge test.’’ Both of these techniques, with further refinement, may be useful in the older child and adolescent who would be able to cooperate. These tests have not yet been incorporated into clinical practice. Of course, the ideal test would be a ‘‘biomarker’’ (or perhaps a panel of biomarkers) noninvasive and able to distinguish among active EoE, inactive EoE, other types of esophageal inflammation, and normal. In fact, a great deal of effort has been expended to develop just such a test (9–14). This degree of intense research indicates that there is a recognized need of better answers for diagnosis and monitoring of EoE. Lowry’s study, although not the answer, is a step in the right direction. We need more steps.