Portal vein thrombosis and food protein-induced allergic pro
Peripheral blood eosinophilia is identified in numerous medical conditions associated with allergic, infectious, and inflammatory processes mostly as reactive eosinophilia with or without tissue eosinophilia. In hospitalized neonates, eosinophilia is common with an inverse relationship with gestational age and occurs solely as mild eosinophilia in the majority of cases. In the literature, eosinophilia has been proposed as a possible risk factor for venous thromboembolism. However, few reports are found on thromboembolic events including portal vein thrombosis (PVT) associated with eosinophilia in the newborn period.

A male infant with a weight of 2980 g (91st percentile) was born to a 37-year-old woman (gravida 2 and para 2) at 34+ 5 weeks’ gestation via normal spontaneous vaginal delivery. Apgar scores were 8 and 9 at 1 and 5 min after birth, respectively. The mother and other family members had no known allergies and no other particular medical history including the maternal history of diabetes, hypertension, dyslipidemia, and neurologic disease, with the mother’s consumption of a small amount of cow’s milk only as food additives during pregnancy. The pregnancy was not complicated by any abnormalities encompassing maternal fever, gestational diabetes, preeclampsia, premature or prolonged rupture of membranes, and placental abruption. The placental examination was unremarkable.

The infant’s general condition was good and oral intake commenced with a total of 60 ml of preterm formula milk. Four hours after initial feeding, three episodes of non-projectile, non-bilious emesis developed with approximately 5 ml milky vomitus on each occasion, followed by hematochezia 5 h later. Initial laboratory evaluation demonstrated a mild leukocytosis (white blood cells 11,400/μL) and eosinophilia (eosinophil fraction 14% and eosinophils 1530/μL), raised D-dimer 1718.3 vs. control < 500 ng/mL DDU, and mild conjugated hyperbilirubinemia (total bilirubin 1.5 mg/dL with the direct fraction 40%), with the other following data (hemoglobin 13.0 g/dL, hematocrit 37.7%, platelets 274,000/μL, C-reactive protein 0.04 mg/dL, prothrombin time 13.4 vs. 10.1–12.6 s with the international normalized ratio 1.19 vs. 0.93–1.13, partial thromboplastin time 42.8 vs. 23.6–31.1 s, antithrombin III 43%, and fibrinogen 256 vs. 180–350 mg/dL). Serum total immunoglobulin E (IgE) was 0.1 IU/ml (normal values < 5.0) and specific IgEs to cow’s milk proteins (CMPs) were negative. The Apt test for fresh blood in the stools did not change color and fecal occult blood was positive. A chest-abdomen plain radiograph showed a normal bowel gas pattern without other abnormalities. Oral feeds were discontinued from postnatal day 1. Total parenteral nutrition was instituted on day 2 and maintained until day 9. The stools mixed with macroscopic bleeding more than in the form of spots persisted during the first 3 days of life. From day 5, oral feedings were reintroduced with breast milk without maternal diet modification and/or casein hydrolyzed milk, which was tolerable without reactions including gastrointestinal symptoms and metabolic acidosis.

On day 6, abdominal ultrasonography revealed a non-obstructive thrombus within the umbilical-portal confluence of the left portal vein as a hypoechoic tubular structure. On day 19, the peak eosinophil count of 3790/μL was observed with a low serum 25-hydroxyvitamin D 16.1 ng/mL (insufficiency < 30 and deficiency < 10). On day 75, the eosinophil count decreased to 590/μL and a supervised oral challenge to cow’s milk was performed. Feeding intolerance with vomiting and blood-tinged stools was noted and the feeding was changed back to the casein-hydrolyzed formula. At 6 months of age, an oral re-challenge to regular cow’s milk feeding was attempted and no reaction was observed. The sonographic signal of the intraluminal thrombus gradually decreased in size and became heterogeneously hyperechoic over time. At 1 year of age of the last follow-up ultrasonography, the thrombus completely resolved. The infant showed good weight gain with well-tolerated formula feeds.