Abstract
BACKGROUND: Upper gastrointestinal hemorrhage is a life-threatening manifestation of cow's milk protein allergy (CMPA). We analyze the clinical characteristics of a case of milk protein allergy manifested as severe upper gastrointestinal hemorrhage. CASE SUMMARY: The hospital admitted a 2-month-old male infant due to "melena for 6 days, hematemesis twice". The main symptom was melena, initially occurring once or twice per day, then gradually increasing to five or six times per day at their peak. During the course of the illness, the infant vomited blood, but there were no reports of vomiting, fever, pale complexion, dyspnea, wheezing, or difficulty breathing. Laboratory tests showed hemoglobin level of 87 g/L, platelet count of 349 × 10(9)/L, and eosinophil percentage of 0.031. Coagulation studies were normal. After avoiding certain foods and feeding with an amino acid formula for 2 weeks, a repeat gastroscopy revealed less bleeding. After six weeks, a positive oral food challenge test confirmed a severe CMPA. At the 4-month follow-up, there was no gastrointestinal bleeding, and the infant was growing and developing well. CONCLUSION: The manifestations of milk protein allergy are diverse and nonspecific, with gastrointestinal bleeding being less common, especially in infants. When infants present with unexplained massive hematemesis, it's critical to investigate the possibility of CMPA.