milk intolerance

Last reviewed 01/2018

Milk Intolerance

• both health care professionals and parents frequently use milk intolerance to describe a whole host of symptoms most commonly seen in infants who are fed commercially prepared formulas. In actuality, milk intolerance is a broad and generic term that includes the more specific maladies of lactose intolerance, cow's milk protein intolerance (CMPI), and cow's milk allergy (CMA)
  • lactose intolerance
    • a result of lactase deficiency and is a form of carbohydrate malabsorption
    • when lactase is absent or deficient, hydrolysis of the sugar lactose is incomplete
    • because it is osmotically active, the undigested sugar will pull fluid into the intestine
      • hydrogen and lactic acid, in addition to other organic acids, are produced when colonic bacteria act on the undigested sugar
      • the combined osmotic effect of the undigested sugar and organic acids results in the passage of acidic diarrheal stools
      • these stools can produce significant skin irritation and breakdown
      • infants with lactose intolerance may also present with abdominal distension and vomiting
  • cow's milk protein intolerance (CMPI), and cow's milk allergy (CMA)
    • intolerance or allergy to cow's milk is more complex and less well understood
    • Cow's milk protein allergy/cows' milk allergy
      • defined as adverse reactions to cow's milk that can be reproduced and are immune-mediated
        • most common immune responses are immunoglobulin E (IgE)-mediated, cell-mediated (non-IgE), or the combination of the two
    • Cow's milk protein intolerance/cow's milk intolerance
      • not immune-mediated
        • said to be undefined because an immune component is not clearly identifiable (1,2,3)
    • definition of CMPI/CMI does not include the symptoms of lactose intolerance or the presence of incidental isolated GI tract infections
    • children with CMA or CMI can present with a variety of clinical features that are cutaneous, GI, or respiratory in origin
      • most common cutaneous reactions include:
        • urticaria, atopic dermatitis, angioedema, and contact rashes
      • infants with GI reactions can present with various clinical features including
        • nausea, vomiting (including hematemesis), colic, diarrhoea, (including occult and frank blood), enterocolitis, colitis, constipation, and transient enteropathies
      • respiratory reactions include:
        • rhinoconjuctivitis, asthma, wheezing, laryngeal edema, otitis media, and anaphylaxis

Reference:

• 1. Host A., Clinical course of cow's milk protein allergy and intolerance. Pediatr Allergy Immunol 1998; 9 (Suppl 11):48-52
• 2. Host A. Cow's milk protein allergy and intolerance in infancy. Pediatr Allergy Immunol 1994;5:5-36.
• 3. Wilson J. Milk Intolerance: Lactose Intolerance and Cow's Milk Protein Allergy. Newborn and Infant Nursing Reviews 2005; 5 (4): 203-207.