by Olivia Walsh, Paediatric Dietician.
Many people often confuse the terms lactose intolerance and cow’s milk protein allergy. Although they may share some symptoms they are two distinctly different conditions that are diagnosed and managed in different ways. Therefore it is important that infants are not misdiagnosed.
|Table 1: Symptoms associated with CMPA & LI|
|Cow’s milk protein allergy||Lactose Intolerance|
|IgE mediated||Non IgE mediated||All forms|
|Gastro-intestinal system||Acute angioedema (lips, tongue, palate)
Acute vomiting /diarrhea
Colicky abdominal pain
Gastro-oesophageal reflux disease
Loose frequent stools
Blood and /or mucous in stools
Food refusal /aversion
Pallor and tiredness
Faltering growth & ≥ 1 of above symptoms (with / without serious atopic dermatitis
|Respiratory system||Upper respiratory tract symptoms (nasal itching, sneezing, rhinorrhea or congestion – with or without conjunctivitis)
Lower respiratory tract symptoms (cough, chest tightness, wheezing, or shortness of breath)
Food-protein induced enterocolitis
Food-protein induced proctocolitis
Food-protein induced enterocolitis syndrome
Cow’s milk protein allergy is an allergy which involves interaction between the protein in cow’s milk and the body’s immune system. It can be further classified into IgE mediated (i.e. immediate type allergy) and non IgE mediated (i.e. typically delayed type onset). Symptoms related to IgE mediated cow’s milk protein allergy (CMPA) typically appear within two hours of ingesting cow’s milk, whereas symptoms related to non IgE mediated CMPA tend to appear >2hrs and up to 72hours or a couple of days. Symptoms can involve several different organ systems: the skin, the digestive system and the lungs; See Table 1 for symptoms associated with both IgE and non IgE mediated CMPA.
Lactose intolerance is an inability to digest lactose, the sugar found in milk and dairy. It usually occurs when there is a deficiency in the enzyme – lactase which prevents the body from breaking down lactose. It does not involve the immune system like in CMPA. Although there are a number of different types of lactose intolerance (LI) the two main types are Primary LI and Secondary LI. Primary LI is rare in infants in Ireland and secondary LI is only present when there has been damage to the gut lining that produces lactase e.g. following severe gastroenteritis, which results in a temporary intolerance.
Cow’s milk protein allergy (CMPA) is the most common food allergy in infants and young children estimated to affect 1.9-4.9% of children under the age of one. CMPA is often outgrown so is less commonly seen in older children and adults. The cause of food allergies is unknown but the incidence is highest in children with a family or personal history of atophy (asthma, hayfever, eczema, food allergies). The majority of the children in Ireland and the UK present with non IgE mediated CMPA. There is evidence that IgE mediated CMPA is likely to persist longer than non IgE mediated CMPA.
Most children will present early in infancy if formula fed or on weaning to solids if breastfed. Beta-lactoglobulin is the most abundant cow’s milk protein and causes symptoms of CMPA in up to 76% of CMPA infants. Although it is less common, babies who are breastfed may react to cow’s milk protein in the mother’s diet transmitted through breastmilk. Breast milk doesn’t contain beta-lactoglobulin but if the mother consumes cow’s milk it will be present in 95% of breast milk samples.
How can I get my infant / child tested for CMPA?
If you suspect your child has CMPA it is recommended that you contact your GP or Paediatrician. A detailed clinical history is the most important first step in determining whether your child may have CMPA. Following on from this the health care professional should make a decision regarding possible testing:
- If IgE mediated CMPA is suspected, then either a skin prick test and / or a specific IgE blood test to cow’s milk should be performed. Unfortunately, these two tests are usually only available in the hospital setting. The results of the allergy test should always be reviewed in the context of the allergy focused clinical history.
- If non IgE mediated CMPA is suspected, a trial elimination diet of 2-6 weeks should be recommended followed by a home food challenge or reintroduction. The elimination period will involve either choosing an appropriate hypoallergenic formula for bottle fed infants or maternal avoidance of cow’s milk in breastfed infants. There are no other reliable tests for non IgE mediated allergies.
- Parents should be aware that vega tests, kinesiology, hair analysis and IgG testing in the diagnosis of food allergy have no scientific evidence and are not advisable.
What is the management for CMPA?
Management is the removal of all cow’s milk protein from the infant’s diet whilst ensuring nutritional adequacy – this includes removing all cow’s milk protein in foods if your infant is on solids, something which is often overlooked. Most guidelines (NICE, MAP, BSACI, INDI) recommend referral to a dietitian if your infant needs to eliminate cow’s milk protein from the diet. Removal of cow’s milk from a child’s diet is a major decision. It has significant nutritional – including protein, calcium, vitamin B2, vitamin B12, vitamin A, and family consequences. Children older than two years who have avoided milk have been found to be smaller in weight and height in various studies compared to children of the same age on fully inclusive diets. Therefore close monitoring of growth is essential for infants and children with CMPA. Milk must be replaced with a nutritional equivalent. For breast-fed infants, maternal avoidance of cow’s milk is advised. Mothers avoiding cow’s milk should supplement their diet with a calcium and vitamin D supplement. Formula fed infants will usually be trialled on an extensively hydrolysed formula (EHF) in the first instance (e.g. Aptamil Pepti, Nutramigen Lipil) with amino acid formulas (e.g. Neocate, Puramino) only used in infants with severe symptoms or those who do not tolerate or respond to EHF. There are many factors to consider when choosing what formula is suitable for infants with CMPA. Most extensively hydrolysed formulas can be purchased in a pharmacy but a prescription is needed for amino acid formulas. Some children need to remain on hypoallergenic formulas until they are 2 whilst others can stop between 12-24months dependent on growth and their nutritional intake / status. Goats milk and soya milk based formulas are not recommended as there is a high incidence of cross-reactivity between cow & goat milk proteins & soya is not tolerated in up to 50% of children with CMPA. Rice milk is not recommended in children under the age of 4.5 years as it contains relatively high levels of arsenic
Weaning and beyond
A great variety of milk-free replacements for key dietary staples such as spreading fats, cheese, yogurts, ice-creams and creams have become available in larger supermarkets and health food stores over recent years. The majority of such are based on soya, are extremely palatable, and are easy to use in standard recipes. In addition soya beans from which these products are produced offer a high quality source of protein and heart healthy fats (omega 3 and omega 6 plant-based polyunsaturated fats) and are suitable for incorporation in the diets of other family members who do not require a dairy-free diet. However for those who cannot tolerate soya there are dairy and soya free options of all of the above listed staples.
Dairy is the main source of calcium in the Irish diet especially for infants and children. Therefore, it is essential to offer parents suitable calcium rich dairy alternatives, particularly when compliance with consumption of the choses milk alternative is low. Some of the dairy free food are calcium fortified and others are fortified with vitamin B12.
Following the introduction of EU-wide allergen labelling directive all manufacturers of pre-packaged foods have to clearly list if the food contains mammalian milk or derivatives on the ingredients list of every product label. The following are just some of the ingredients that contain milk; Lactoglobulin, Casein or curd, Milk solids, Caseinates, Non fat milk solids, Hydrolysed casein, Whey, Whey solids, Butter oil, Whey syrup, Hydrolysed whey protein, Hydrolysed whey sugar/solids. Some foods that don’t contain food labels (e.g. in bakeries) may contain hidden dairy and therefore an awareness of the ingredients of these foods is warranted.
Implementing a dairy free diet for infants and toddlers poses a number of challenges for families and appropriate, ongoing support and monitoring is needed to ensure successful, safe management which optimises growth and normal dietary behaviours.
Olivia Walsh (MINDI, BSc Hons, PgDip), is a CORU registered paediatric dietitian with 9 years’ clinical experience. She has a wide range of experience of working with infants, toddlers, children, adolescents and their families in particular, and has worked in both the UK and Ireland in large teaching hospitals as well as community settings. Her specialist interests include paediatric food allergies and intolerances, feeding difficulties and problem feeders, preterm nutrition amongst others. Olivia provides a part-time children’s dietetic clinic in the Market Green Medical Centre in Midleton, Co. Cork. See www.nutrition4u.ie or contact 087-4321943 to book an appointment or enquire about the service . Phone and skype consultations are available and all fees can be claimed back as part of your health insurance or via the Med 1 form.