[Case report: allergy to cow's milk protein]

Milk-based formulas can induce cow’s milk protein allergy (CMPA) in infants. This article discusses two cases of severe CMPA in infants exposed to casein-based formulas.

Case N°1: A 7 day old boy developed diarrhea with no improvement despite several courses of antibiotic and switching to formula without lactose. At 2 months of age he had a hemoglobin 8.6 mg/dL, IgE = 17.8 IU/ml (normal <1.5 UI/ml) and a CD4/CD8 ratio = 0.16 (normal 1.5 – 2.5). Upper endoscopy biopsies showed duodenal atrophy. He received a casein hydrolysate formula with decreased fecal flow but continued diarrhea. At 3 months of life he was changed to an amino acid formula with cessation of diarrhea in < 48 hours, resumption of normal growth and normalization of duodenal histology. Case N°2: A 10 month old boy had a 6-day history of vomiting, diarrhea and edema. His albumin was 2.35 mg/dL. An upper endoscopy biopsy showed severe duodenal atrophy. He received a casein hydrolysate with good tolerance and resolution of the edema. At 26 months of age, and endoscopic duodenal biopsy showed regeneration of the mucosa.

The CMPA is a frequent diagnosis in young infants that can be confused with infection. An early diagnosis is key to a positive outcome.