A RARE AND CHALLENGING CASE OF EOSINOPHILLIC PERITONITIS IN A PATIENT UNDERGOING CONTINUOUS AMBULATORY PERITONEAL DIALYSIS

Introduction:

Eosinophilic peritonitis (EP) is an uncommon condition that remains challenging to diagnose. EP shares clinical symptoms with infective peritonitis, such as abdominal pain, turbid PD effluents, and an increased white blood cell (WBC) count in dialysate, leading to frequent misdiagnosis. Currently, there are no established guidelines for the diagnosis and treatment of EP

Methods:

Herein, we report a case of successful treatment of an EP patient by anti-allergic drugs

Results:

An 57-year-old female patient with a medical history of ESKD commenced renal replacement therapy using PD for 2 weeks. A Tenckhoff catheter was inserted by laparoscopic surgery. The PD regimen used Dianeal 1.5%, Baxter International Inc. Two weeks after initiating PD, the patient was hospitalized after detecting turbid peritoneal effluent. Physical examination at admission showed fever, mild abdominal pain, no diarrhea, and ultrafiltration volume was unchanged. There were no signs of allergic reactions. The initial dialysate WBC count was 359/mm³, with a differential of 20% neutrophils, 15% lymphocytes, and 65% eosinophils. Laboratory tests revealed a WBC count of 10.8 G/L (0.21% eosinophils), C-reactive protein of 102 mg/L. She did not meet the diagnostic criteria for bacterial peritonitis , however, it could not be clinically ruled out at that time. We decided to use empiric antibiotics while waiting for culture results and repeat infection tests. As the patient was in a tuberculosis endemic area and had a high risk of fungal infection, we also performed direct microscopy for fungi and PCR of the effluent for tuberculosis - these were potential causes that could increase eosinophils in the fluid without being related to allergies. In addition, we assessed the patient's allergic status; however, the IgE test result was negative. The patient was started on intraperitoneal cefazolin 1 g per day and ceftazidime 1 g per day. Within two days, the repeat dialysate WBC counts increased to 1705/mm³, consisting of 35% neutrophils, 10% lymphocytes, 40% eosinophils. Despite these increases, the patient's peritonitis symptoms did not change significantly, with no deterioration in ultrafiltration status. On the third day of treatment, culture results were negative for bacteria, not detect fungi, and the tuberculosis PCR test was also negative. Subsequent serum laboratory results showed a WBC count of 6.32 G/L (78.1% neutrophils, 6.89% eosinophils) and a procalcitonin level of 0.48 ng/mL. Antibiotics were discontinued. Treatment was changed with methylprednisolone 16 mg once daily and desloratadine 5 mg once daily. After two days of anti-allergic treatment, the PD effluent cleared significantly, and the WBC count was normalized. The patient was discharged after 12 days and continued on methylprednisolone and desloratadine at the same doses for five more days at home. Dialysate WBC counts at 30 days and 90 days follow-up were 48/mm³ (6% neutrophils, 64% lymphocytes, 10% eosinophils) and 33/mm³ (10% neutrophils, 90% lymphocytes, 0% eosinophils)

Conclusions:

This case illustrates the importance of considering EP in the differential diagnosis of cloudy peritoneal effluent, even in the absence of typical signs of infection or allergy. Timely diagnosis and appropriate treatment can prevent unnecessary antibiotic use, shorten hospital stays, and improve patient outcomes

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.