The intriguing condition of eosinophilic sialodochitis: insights into an emerging type 2 disorder

Background: Eosinophilic sialodochitis is a rare and increasingly recognized inflammatory disorder of the salivary glands, characterized by eosinophil-rich mucus plugs, periductal eosinophilic infiltration, and frequent association with type 2 disorders. Methods: A systematic search was conducted on PubMed, Embase, Scopus, and Web of Science for papers reporting on eosinophilic sialodochitis. PRISMA 2020 guidelines were followed, and the study protocol was registered in PROSPERO with registration number CRD42023433994. Data was summarized descriptively and presented as percentages or medians with interquartile range. Results: A total of 157 studies were identified and 21 met the inclusion criteria of the present review, comprising 179 patients. The majority were female (73%) and their ages ranged from 15 to 80 years old. Eosinophilic sialodochitis often presented with multiglandular involvement of the parotid glands. Allergic rhinitis (72%) and asthma (28%) were the most common associated type 2 comorbidities, while elevated serum IgE and blood eosinophil count were frequently reported. Diagnosis was based on different examinations, ranging from ultrasonography to MRI, fine-needle or core-needle biopsy, and conventional sialography. Therapeutic interventions included antihistamines, montelukast, and oral corticosteroids. Sialendoscopy and sialadenectomy were used in refractory cases, while biologics such as dupilumab, benralizumab and mepolizumab were employed only in 4 patients. Conclusions: This review highlights the diagnostic complexity, therapeutic challenges, and potential role of targeted biologic therapies in managing eosinophilic sialodochitis.