comparison (lactose intolerance with cow's milk protein allergy (CMPA))

Last edited 03/2020 and last reviewed 01/2023

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General comparison - lactose intolerance versus cow's milk protein allergy

  lactose intolerance - lactose intolerance results from a reduced capacity to digest lactose - a sugar cow's milk protein allergy
Epidemiology

Congenital lactose intolerance is very rare

Primary lactose intolerance develops when levels of the enzyme lactase naturally reduce, which usually occurs after 3 years of age in some populations (for example, Africans and Asians)

Secondary lactose intolerance as a result of mucosal damage - most commonly following severe gastroenteritis. However secondary lactose intolerance may also occur secondary to epithelium damage caused by other gastroenterological diseases such as in coeliac disease and cow’s milk allergy

estimated that up to 4.9% of children suffer from cow’s milk protein allergy (CMPA) (5)

may be IgE mediated CMPA, non IgE mediated CMPA or mixed

 

General features

Lactose intolerance causes symptoms that only in the bowel, for example, abdominal pain, loating, flatus, and diarrhoea

Lactose intolerance does not cause vomiting or GORD (6)

Secondary lactose intolerance presents as a result of mucosal damage - usually following severe gastroenteritis.

Secondary lactose intolerance is temporary, as long as the gut damage can heal. When the cause of the damage to the gut is removed, the gut will heal, even if the baby is still fed breastmilk, or their usual formula.

Breastmilk contains lactose (as does any mammalian milk) and decreasing dairy intake in maternal diet does not alter the amount of lactose in breastmilk (6)

Estimated that fifty to sixty per cent of affected children have skin symptoms and/ or gastrointestinal symptoms and 20-30% have respiratory symptoms (4)

CMPA may be the underlying cause of gastro-oesophageal reflux disease (GORD) in up to 40% of infants and young children (4)

CMPA will resolve in 40-50% of infants by 1 year, 60-75% by 2 years and 85-90% by 3 years (4)

  • however the natural history is actively changing, showing a definite trend to persist longer, especially the IgE-mediated clinical expression of CMPA (4)

Only about 10% of babies with CMPA will require an amino acid formula (AAF). The remainder should tolerate an extensively hydrolysed formula (EHF) (6)

10-14% of infant with CMPA will also react to soya proteins (and up to 50% of those with non-IgE mediated CMPA). But because of better palatability soya formula is worth considering in babies>6months (6)

 

 

Comparing lactose intolerance versus IgE mediated cow's milk protein allergy versus non-IgE mediated cow's milk protein allergy

  lactose intolerance IgE mediated cow's milk protein allergy non-IgE mediated cow's milk protein allergy
Mechanism

Lactose intolerance results from a reduced capacity to digest lactose, a sugar

Congenital lactose intolerance

  • very rare and presents only in isolated populations, for example, some families in Finland and Russia.

Primary lactose intolerance

  • develops when levels of the enzyme lactase naturally reduce
  • usually occurs after 3 years of age in some populations (for example, Africans and Asians)

Secondary lactose intolerance

  • presents as a result of mucosal damage, usually following severe gastroenteritis but also when the epithelium is damaged such as in coeliac disease and cow’s milk allergy
    • usually reversible once the epithelial lining has repaired
    • children with suspected lactose intolerance do not usually require any testing and should improve within 48 hours on a low lactose diet
    • in secondary lactose intolerance, for example after severe gastroenteritis, lactose can usually be tolerated again by 6 weeks

Notes:

  • except after a gastrointestinal infection, infants with gastrointestinal symptoms on exposure to cow’s milk are more likely to have cow’s milk allergy than lactose intolerance

IgE mediated allergic reaction to milk protein

  • IgE-mediated reactions typically occur immediately after ingestion
  • IgE-mediated reactions are immediate, requiring only a small quantity of food to be ingested, enabling rapid identification of the allergenic foods
  • - involve the production of specific IgE antibody protein molecules directed against the food protein. It is a well defined mechanism, which is relatively easy to diagnose using a combination of clinical history and validated tests such as skin prick tests and specific IgE’s

Non-IgE mediated allergic reaction to milk protein

  • non-IgE mediated are delayed and take up to 72 hours to develop, but still involve the immune system (4) - therefore the identification of suspect foods is often difficult. The mechanism is unclear, it is harder to diagnose and there are no validated tests to confirm such an allergic reaction
  • symptoms of non-IgE mediated disease are commonly wrongly labelled as symptoms of intolerance, using either the terms 'lactose intolerance' or 'milk intolerance' (2)
Symptomatology

symptoms occur only in the bowel - for example, abdominal pain, bloating, flatus, and diarrhoea

lactose intolerance does not cause of rectal bleeding (which may occur in cow's milk allergy)

Possible dermatological features include:

  • pruritus
  • erythema
  • acute urticaria (localised or generalised)
  • acute angioedema (most commonly in the lips and
    face, and around the eye

Possible gastroenterological features incldue:

  • agioedema of the lips, tongue, and palate
  • oral pruritus
  • nausea
  • colicky abdominal pain
  • vomiting
  • diarrhoea

Respiratory system (usually in combination with one or more of the above symptoms and signs)

  • upper respiratory tract symptoms (nasal itching,
    sneezing, rhinorrhoea, or congestion, with or without
    conjunctivitis)
  • lower respiratory tract symptoms (cough, chest
    tightness, wheezing, or shortness of breath

Other

  • sgns or symptoms of anaphylaxis or other systemic allergic reactions

Possible dermatological features include:

  • pruritus
  • erythema
  • atopic eczema

Possible gastroenterological features include:

  • gastro-oesophageal reflux disease
  • loose or frequent stools
  • bood and /or mucus in the stools
  • abdominal pain
  • infantile colic
  • food refusal or aversion
  • constipation
  • perianal redness
  • pallor and tiredness
  • faltering growth plus one or more gastrointestinal symptoms above (with or without significant atopic eczema)
  •  

 

 

 

 

Tests Exclusion diet (low lactose) (symptom improvement) and then reintroduction (symptom recurrence). Usually improve within 48 hours of exclusion

An infant with suspected IgE-mediated milk allergy will require testing for specific IgE to milk (skin prick test or blood tests) - iInfants with suspected non-IgE-mediated disease do not need these tests

Exclusion diet (No milk protein) (symptom improvement) and then reintroduction
(symptom recurrence). May take 4–6 weeks
for symptoms to improve (2)
Dietary advice
(including
formulas)
Low lactose diet - exclude cow’s milk and foods containing cow’s milk, although some with low lactose may be tolerated by some individuals If secondary, should resolve by 6 weeks Managed via secondary care - a diet free from cow’s milk protein. Exclude all cow’s milk and products

Dietary management involves removing the allergenic protein from the diet

  • all dairy products must be removed from the diet of a breastfeeding mother if milk allergy is suspected in the infant and calcium supplements given
  • in a formula-fed infant, choice of formula is determined by the severity of the symptoms
    • most infants respond to extensively hydrolysed formulas, where the milk protein is broken down
    • amino acid formulas should be reserved for severe symptoms and those not responding to an extensively hydrolysed formula
      • should also be used first line if top-up feeds are required in an infant who is exclusively breast fed and shows symptoms suggestive of cow’s milk allergy
  • acquisition of tolerance in cow’s milk allergy should be considered after at least 6 months on a diet free from milk protein
    • likely that tolerance to extensively baked milk products will occur before that to less well cooked milk

Refer to secondary care only if symptoms severe (4)

 

 

Notes:

  • soya is not recommended before 6 months of age due to it containing isoflavones, which may exert a weak oestrogenic effect. There is also a risk of cross-reactivity: up to 14% of those with IgE-mediated cow’s milk allergy also react to soya and up to 60% of those with non-IgE-mediated cow’s milk allergy
  • rice milk is not recommended in those aged <4.5 years due to the arsenic content; and there is cross-reaction between mammalian milks
  • goat’s milk and products are not suitable for infants with cow’s milk allergy

Reference:

  • NICE. Food allergy in children and young people: diagnosis and assessment of food allergy in children and young people in primary care and community settings. CG 116. 2011
  • Walsh J et al. Differentiating milk allergy (IgE and non-IgE mediated) from lactose intolerance: understanding the underlying mechanisms and presentations. Br J Gen Pract 2016; DOI: 10.3399/bjgp16X686521
  • Ludman S, Shah N, Fox AT. Managing cow’s milk allergy in children. BMJ 2013; 347: f5424.
  • NHS Fife. Diagnosis and Management of Infants with Suspected Cow’s Milk Protein Allergy. A guide for healthcare professionals working in primary care (Accessed 8/3/2020)
  • Fiocchi A, Brozek J, Schunemann H, Bahna SL, Von BA, Beyer K et al: World Allergy Organisation (WAO) diagnosis and rationale for action against Cow’s milk allergy (DRACMA) guidelines. World Allergy Organ J 2010
  • Wessex Infant Feeding Guidelines and Appropriate Prescribing of Specialist Infant Formulae (Accessed 8/3/2020)