What is the likely diagnosis for a 2.5-year-old child with oral allergy syndrome (OAS) and diarrhea after consuming milk, presenting with intermittent diarrhea?

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Differential Diagnosis for a 2.5-Year-Old with Reactions to Milk

Single Most Likely Diagnosis

  • Cow's Milk Protein Allergy (CMPA): This is the most likely diagnosis given the child's reactions to milk, including oral-facial allergy and diarrhea. CMPA is a common condition in infants and young children, characterized by an immune-mediated reaction to one of the proteins in cow's milk (casein or whey).

Other Likely Diagnoses

  • Lactose Intolerance: This condition is caused by a deficiency of the enzyme lactase, which breaks down lactose, a sugar found in milk. Symptoms include diarrhea, gas, and bloating after consuming lactose-containing products.
  • IgE-Mediated Milk Allergy: Similar to CMPA but involves an immediate allergic reaction mediated by IgE antibodies, which can cause a range of symptoms from mild hives to life-threatening anaphylaxis.
  • Gastroenteritis: An infection of the intestines and stomach, typically caused by a virus or bacteria, leading to symptoms like diarrhea, vomiting, and abdominal pain.

Do Not Miss Diagnoses

  • Celiac Disease: An autoimmune disorder where the ingestion of gluten leads to damage in the small intestine. It can present with diarrhea, abdominal pain, and failure to thrive. Although less common in this age group with these specific symptoms, it's crucial not to miss due to its long-term implications.
  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can present with chronic diarrhea, abdominal pain, and weight loss. Early diagnosis is critical for management and preventing complications.

Rare Diagnoses

  • Congenital Lactase Deficiency: A rare genetic disorder causing a severe deficiency of lactase enzyme, leading to malabsorption of lactose from birth.
  • Secondary Lactose Intolerance: Due to another condition affecting the small intestine, such as celiac disease or gastroenteritis, which damages the lining of the small intestine where lactase is produced.
  • Food Protein-Induced Enterocolitis Syndrome (FPIES): A non-IgE-mediated food allergy characterized by repetitive vomiting, diarrhea, and abdominal pain, typically after ingestion of common food proteins like cow's milk.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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