An 11-year-old boy was assessed at the Pediatric Emergency Room because of a 3-day history of abdominal pain and distension. He was correctly vaccinated and had no history of interest, except for a self-limited gastroenteritis, 14 days prior to the beginning of this episode.
The patient exhibited regular appearance due to spontaneous pain that intensified with movement, fever (38.3 C) and tachycardia (124 bpm) with normal blood pressure (104/62 mmHg). An increase of 3.5 kg over his usual weight was estimated. Physical examination revealed non-pruritic erythematous plaques on the abdomen, pubis and proximal segments of both lower limbs (Figure 1). The abdominal exam was notable for distension, diffuse pain and tenderness. The lower back was painful upon palpation. He had pitting edema at the abdominal wall, lumbar region, and distal segments of the lower limbs. Auscultation of the lungs showed decreased vesicular breath sounds at the right base.
Abdominal radiograph was performed showing a probable mass effect on loops of the transverse and descending colon without signs of obstruction. Chest radiograph revealed right pleural effusion. Abdominal CT with contrast was prioritized over ultrasound to better characterize the suspected abdominal mass. It showed ascites, bilateral pleural effusion, lumbar subcutaneous edema and right lower lobe atelectasis with normal cardiac size (Figure 2). Blood analysis revealed an increased white blood cell count of 37.48 x 109/L (neutrophils 34.30 x 109/L), hemoglobin and platelet count in the normal range and no abnormalities in peripheral blood smear. Increased acute phase reactants (C-Reactive Protein 345 mg/L, procalcitonin 2.77 ng/ml), hypoproteinemia with hypoalbuminemia (4.2 g of total proteins/dL with 1.9 g of albumin/dL) and hypogammaglobulinemia (IgG 137 mg/dL, IgG-1 1,060 mg/L, IgG-2 317 mg/L, IgG-3 139 mg/L, IgA 43 mg/L, other isotypes within normal ranges) were detected. Ions, amylase levels, liver enzymes, renal function parameters were in normal range. Biological parameters of heart function such as troponins and N-terminal prohormone of brain natriuretic peptide (NT-pro-BNP), were also tested as workup of ascites and pleural effusion, with normal results. The urine study did not show significant proteinuria or hematuria.
With an initial diagnosis of peritonitis and pleural effusion, hospital admission was decided and intravenous antibiotic therapy with cefotaxime was initiated. An exploratory laparoscopy was performed 24 h after admission, exposing purulent peritoneal fluid and ruling out appendicitis or visceral perforations. A routine appendectomy was performed with no abnormal anatomopathological findings. Therefore, secondary peritonitis was excluded. Samples of ascitic fluid were tested for cytobiochemical analyses (562 cells/muL, 57% polymorphonuclear; pH 7.34; glucose 31 mg/dL; protein 0.12 g/dL; LDH 32 U/mL; triglycerides 54 mg/dl) and microbiological studies (Gram and auramine stains, bacterial and mycobacterial cultures, as well as polymerase chain reaction for Mycobacterium tuberculosis DNA were all negative). Due to the prevalence of methicillin-resistant Staphylococcus aureus in our environment (~15%), vancomycin was added, and fluid restriction was prescribed with strict monitoring of fluid balance and daily weight. With the suspicion of PP with hypoproteinemia, complementary examinations dismissed nephrotic syndrome, liver failure, alpha-1-antitrypsin (alpha1-AT) deficiency, diabetes mellitus, lupus erythematosus, giardiasis, celiac disease, tuberculosis and immunodeficiencies. Biochemical stool analysis showed elevated alpha1-AT (1.9 mg/g of stool; reference value < 0.3 mg/g) and increased clearance of alpha1-AT (107.7 mL/24 h; reference value < 27 mL/24 h), compatible with protein-losing enteropathy (PLE).
He had a favorable clinical course with a gradual decrease in inflammatory parameters, progressive improvement in serum protein and gamma globulin levels, and total reabsorption of pleural effusion and peritoneal fluid during admission. The patient completed 21 days of antibiotic therapy (14 days of intravenous cefotaxime and 10 days of intravenous vancomycin and, after discharge, 7 days of oral amoxicillin-clavulanic acid).
Further studies to identify the cause of this PLE included a normal colonoscopy and a gastroscopy that showed a very erythematous and discretely edematous mucosa and enlarged gastric folds in the body and fundus of the stomach. Gastric mucosal biopsies revealed an extensive and significant hyperplasia of the foveolar mucosecretory epithelium, causing elongated and tortuous foveolar glands with loss of parietal cells, and edematous lamina propia. No signs of lymphoplasmacytic or neutrophilic infiltrate, intraepithelial lymphocytosis, pathogenic microorganisms or intracellular cytomegalovirus (CMV) inclusions were identified. Duodenal mucosa was preserved. These findings were compatible with MD. The histochemical study for Helicobacter pylori and the immunohistochemical study for CMV were negative (Figure 3). CMV serology was also negative.
In spite of the initial hypogammaglobulinemia of our patient, no intravenous immunoglobulins were administered to prevent the risk of new pyogenic bacterial infections since he showed a good clinical evolution and his plasmatic gammaglobulin and protein levels spontaneously increased slowly along the next weeks. Analytical controls performed 6 months later showed a complete recovery of total plasma proteins and albumin levels. Immunoglobulin levels normalized 10 months after hospital admission. After 12 months of follow-up, the patient has not presented any recurrence. A summary of his clinical course is showed in Figure 4.