Eosinophilic esophageal myositis: a comparative study of distinguishing features, diagnostic challenges, and therapeutic insights.

BACKGROUND

Eosinophilic esophageal myositis (EoEM) involves eosinophilic infiltration of muscle layers but spares the epithelium, differing from eosinophilic esophagitis (EoE). EoEM is rare and underrecognized, with challenges in diagnosis and treatment.

OBJECTIVES

To compare the clinical, endoscopic, pathological, and manometric characteristics of EoEM with mucosal-predominant and muscle-predominant EoE, and to elucidate differences and interconnections between these conditions.

DESIGN

Retrospective cohort study with literature review.

METHODS

The retrospective study included patients diagnosed with mucosal-predominant EoE (n = 21), muscle-predominant EoE (n = 6), and EoEM (n = 7) at Nanjing Drum Tower Hospital from 2019 to 2024, along with a review of EoEM cases reported in the literature (n = 11). Muscle thickness was measured using endoscopic ultrasonography and computed tomography (CT). High-resolution esophageal manometry was performed to evaluate esophageal motility and diagnose motility disorders according to the Chicago Classification v4.0 criteria. Clinical, endoscopic, pathological, manometric, and treatment data were analyzed.

RESULTS

EoEM patients were older and had more severe dysphagia, food impaction, and weight loss. Endoscopic findings revealed a distinct corkscrew-like appearance and luminal compression without typical mucosal inflammation. High immunoglobulin E (IgE) may be a marker of EoEM. Compared with muscle-predominant EoE, EoEM patients had higher maximum distal contractile integral values and a higher frequency of Jackhammer esophagus, although they exhibited similar muscle thickness. EoEM patients resisted proton pump inhibitors but responded favorably to oral steroids and Per-Oral Endoscopic Myotomy (POEM).

CONCLUSION

EoEM is characterized by severe esophageal motility dysfunction. Muscle biopsy should be considered in patients with frequent dysphagia, motility disorders, and high serum IgE levels. Oral steroids and POEM effectively relieve symptoms.