A 44-year-old man was admitted to the hospital and reported abdominal distention, with positive shifting dullness and edema in lower limbs. He also complained of acid regurgitation, nausea, and vomiting for 1 month, without fever, abdominal pain, rash, or oliguria. He had been prescribed with penicillin for a week without remission. The patient had history of edema and was diagnosed as nephrotic syndrome 22 years ago but didn’t undergo renal biopsy. He was treated with 60 mg/day prednisone for almost 1 year and tapered to cease until negative proteinuria, while intermittently taking moderate dose of prednisone afterwards whenever urine dipsticks showed positive proteinuria by September 2018. However, he didn’t monitor blood routine examination and serum creatinine. He denied history of asthma, atopy and family history of kidney diseases. The patient was a non-smoker and denied alcohol ingestion. On physical examination, his blood pressure was normal, and cardiopulmonary examination was sound. There was one palpable lymph nodal mass in each side of inguinal region, both were non-tender and firm in consistency, with normal overlying skin. On admission, laboratory data showed nephrotic syndrome with peripheral eosinophilia at 2.1 × 109/L (24.3%) and elevated IgE (171 IU/L). Stool analysis for parasitic eggs and parasites didn’t show abnormalities. Abdominal ultrasonography demonstrated a maximum 10 cm depth of ascites. Computed tomography (CT) revealed multiple mesentery exudation, thickened peritoneum, and ascites, without hepatosplenomegaly, intra- and extra-hepatic bile ducts dilation and intra-abdominal lymphadenopathy. Diagnostic abdominal paracentesis revealed translucent yellow fluid. The white cell count in the ascitic fluid was 200/mm3, with 14% eosinophils. Chemical analysis indicated transudate with serum-acites albumin gradient (SAAG) of 15.4 g/L. Ascitic fluid smears and cultures for bacterial, tuberculous and fungus were negative. Serum immunoglobulin (IgG) level was low, while IgA, IgM, C3 and C4 level was normal. Serum and urine immunofixation electrophoresis showed monoclonal IgG λ, with normal free κ/λ ratio in serum. Bone marrow cytology, histopathology and flow cytometry showed no abnormality. Serum albumin was 18 g/L, 24-h proteinuria was 13.9 g/day (urine volume 1450 ml). Serum creatinine (Scr) progressively elevated from 472 μmol/L to 612 μmol/L within 8 days before admission to hospital, and the peak Scr was 844 μmol/l on 14th day after admission. Serum IgG4 was in the normal range. Anti-PLA2R, anti-dsDNA, ANCA and anti-GBM antibody were all negative. Abdominal ultrasonography demonstrated relatively small size of kidney. Due to the progressively increasing Scr, peritoneal dialysis was performed to relieve uremia symptoms and drainage ascites. Ultrasound-guided renal biopsy was performed. Twenty-eight glomeruli were included in the specimens for light microscopy. Of them, 17 glomeruli were ischemic global sclerosis, 9 glomeruli had segmental glomerulosclerosis with adhesion. Patchy interstitial inflammation of lympoytes, mononuclear cells along with eosinophilils. Immmunofluorescence showed focal IgM ++, C3 +++ in mesangium and segmental sclerosis of glomeruli. The electron microscopy demonstrated diffuse effacement of podocytic foot processes without electron dense deposits. Final pathological diagnosis was focal segmental glomerulosclerosis (FSGS) and acute tubulointerstitial nephritis. There were no signs for IgG4 related disease or monoclonal gammopathy of renal significance (MGRS). Ultrasonography of lymph nodes showed multiple lymphadenopathy in bilateral inguinal regions, with the largest measuring about 2.6 × 0.9 cm in the left inguinal region, and 2.7 × 0.8 cm in the right inguinal region. Screening for HIV, Syphilis, cytomegalovirus (CMV), epstein-barr virus (EBV) and evaluation of interferon-gamma release assay for tuberculosis didn’t show abnormalities. Screen for toxoplasmosis was not performed, since he didn’t have epidemiological history of toxoplasmosis. Surgical excision was performed for one of the enlarged lymph nodes (1.5 cm in diameter) in the right inguinal region. Microscopic examination of H&E-stained sections showed preserved lymph node architecture, follicular and interfollicular hyperplasia, as well as increased eosinophils with formation of eosinophilic microabscesses within the germinal centers. The histopathology of lymph node didn’t show caseous granuloma or other infectious features, such as toxoplasmic lymphadenitis. Hence, a diagnosis of Kimura’s disease was established with relevant clinical details and specific histopathological features. Based on the clinical data, the eosinophilic peritonitis, nephrotic syndrome and lymphadenopathy was considered to be associated with systematic involvement of Kimura’s disease. The patient was prescribed with oral prednisolone therapy (30 mg/day), and underwent continuous ambulatory peritoneal dialysis (CAPD). Anti- infective therapy wasn’t administered. The peripheral and peritoneal eosinophil count decreased rapidly and normalized within 2 days. Forty-five days after prednisolone therapy, 24-h proteinuria reduced to 2.3 g/d (Urine volume 1500 ml), and serum albumin level increased to 31 g/L. Serum creatinine decreased gradually to around 350 μmol/L while peritoneal dialysis dosage had decreased from 4500 ml/d to 3000 ml/d. It’s noteworthy that residual urea clearance (Kt/V) gradually increased to 2.77. Inguinal lymph nodes gradually shrunk in size, with the largest measuring about 1.9 × 0.6 cm in the left inguinal region, and 2.4 × 0.5 cm in the right inguinal region. Prednisolone was tapered to 25 mg/d and peritoneal dialysis dosage decreased from 3000 ml/d to 1500 ml/d after 60 days. The overall conditions maintained stable afterwards.