# An Unusual Gastrointestinal Presentation of Sjogren's Syndrome: A Case Report

## TL;DR

This case report describes a rare instance of Sjogren's syndrome affecting the small intestine, highlighting the diagnostic challenges and treatment response.

## Contribution

This is the first reported case of Sjogren's syndrome involving the small intestine, emphasizing the need for autoimmune enteropathy consideration.

## Key findings

- The patient exhibited cyclic gastrointestinal symptoms linked to Sjogren's syndrome, not typically associated with bowel involvement.
- Treatment with Rituximab led to clinical improvement, suggesting autoimmune enteropathy as a possible mechanism.
- Standard testing failed to detect autoimmune processes, underscoring limitations in current diagnostic approaches.

## Abstract

Sjögren's syndrome (SS) is a chronic autoimmune disorder characterized by lymphocytic infiltration and destruction of exocrine glands, commonly involving the salivary and lacrimal glands, leading to dry mouth and eyes. While SS primarily affects the upper gastrointestinal tract, this case presents a rare small intestine involvement. This patient was diagnosed with SS in 2018 with positive antinuclear antibodies (ANA), rheumatoid factor (RF), SSA antibodies, and salivary lip gland biopsy. By 2021, she developed unusual cyclic episodes of nausea, vomiting, and poor oral intake, resulting in significant weight loss and recurrent hospitalizations. She had frequent hospitalizations due to her recurrent symptoms. Evaluations included esophagogastroduodenoscopy (EGD) and colonoscopy, but pathology was nondiagnostic. Several abdominal and pelvic computed tomography (CT) scans demonstrated bladder edema, pancolitis, and terminal ileitis with mucosal hyperenhancement of the bowel and moderate ascites, likely inflammatory. Her gastric emptying study showed hypermotility. Multiple teams, including Rheumatology, Allergy/Immunology, Gastroenterology, Hematology, and Surgery, were involved. C1 esterase antigen was normal, ruling out hereditary angioedema. PET‐CT scan did not show lymphadenopathy or significant inflammation. Full biopsy for definitive diagnosis was deferred due to concerns of decreased healing with an edematous intestine. She was trialed on Icatibant without benefit. Differentials included lupus peritonitis, protein‐losing enteropathy, and SS intestinal lymphoma. She was discharged on a trial of empiric high‐dose steroids with Rheumatology follow‐up. Symptoms recurred with steroid tapering. Her complement levels decreased with flares and increased with treatment. Rituximab was added, leading to steady clinical improvement and reduced hospitalizations. Bowel involvement has been predominantly described in lupus, often referred to as lupus enteritis or bowel vasculitis. To our knowledge, this represents the first reported case of Sjögren's syndrome. Bowel biopsies are not typically subjected to routine immunohistochemical staining. Consequently, standard testing may be limited in detecting autoimmune processes. This case highlights the diagnostic challenges of SS‐related gastrointestinal manifestations and underscores the importance of considering autoimmune enteropathy, particularly in patients who respond to immunosuppressive therapy.