Cow’s Milk Allergy

From the initial restless nights to the moment when a diagnosis is received, we understand the emotional journey that families experience when their infant is diagnosed with cow’s milk allergy (CMA).

While some parents may encounter a relatively seamless path to accessing appropriate assistance for their baby or child, others may find it can often be an extremely stressful ordeal, spanning months and multiple appointments with healthcare providers.

What is Cow’s Milk Allergy?

Allergy to cow’s milk arises when the body’s immune system mistakenly identifies the proteins present in cow’s milk as threats, triggering an allergic response that manifests as allergic symptoms in your infant or child.

These reactions can occur either immediately (within minutes of milk consumption and up to 2 hours thereafter) or in a delayed fashion (occurring 2 hours to several days after milk intake).

It’s important to note that cow’s milk allergy differs from lactose intolerance, which is caused by insufficient levels of the enzyme lactase needed to digest the milk sugar known as lactose. Primary lactose intolerance is rare in babies. Secondary lactose intolerance can occur for around 3 weeks after viral gastroenteritis due to damage to the lining of the gut.

How do I know if my baby is allergic to cow’s milk?

Identifying whether your baby is allergic to cow’s milk involves observing their reactions and consulting with a healthcare professional. Common signs of cow’s milk allergy in infants can include gastrointestinal symptoms like diarrhoea, vomiting, or constipation, as well as skin reactions such as hives or eczema.

Respiratory issues like wheezing or a runny nose may also occur. In severe cases, an allergic reaction can lead to anaphylaxis, which is a life-threatening condition characterised by difficulty breathing, and swelling inside the throat or going pale or lethargic.

What are the types of cow’s milk allergy?

There are two distinct categories of cow’s milk allergy: immediate and delayed.

Immediate cow’s milk allergy, also referred to as ‘IgE mediated,’ involves the action of IgE antibodies within the immune system. Reactions in this type typically occur rapidly, usually within minutes to up to 2 hours following the consumption of cow’s milk or dairy-containing products. The symptoms can vary but, in some cases, may lead to a severe, life-threatening allergic reaction known as anaphylaxis.

Delayed cow’s milk allergy, often termed ‘non-IgE mediated,’ engages a different component of the immune system, excluding IgE antibodies. Symptoms predominantly affect the digestive system and the skin, and they typically manifest between 4 to 48 hours after the ingestion of cow’s milk or dairy-based foods.

Food protein induced enterocolitis syndrome, also called FPIES, is a delayed food allergy which classically presents during infancy with profuse vomiting 1-4 hours after ingestion of the culprit food allergen. The child can also present as being pale and lethargic. Cow’s milk is the most common food implicated in FPIES reactions.

In both types of cow’s milk allergy, there is often (though not always) a notable family history of allergies, such as eczema, hay fever, asthma, or food allergies, among parents, siblings, or other close relatives.

Diagnosing cow’s milk allergy

If you suspect you or your child is allergic to cow’s milk, you must see your GP or an allergy specialist for an allergy diagnosis. The specific type of cow’s milk allergy your infant or child has will dictate the appropriate management approach, which may differ based on whether the allergy presents immediately or with a delay, your child’s age, and whether they are breastfed, bottle-fed, or a combination of both.

Immediate cow’s milk allergy is typically confirmed by a healthcare professional through a comprehensive process, which involves discussing the reactions and symptoms experienced by the individual, gathering a thorough family allergy history, and conducting an allergy-focused history assessment.

Additionally, the healthcare provider may analyse results from allergy tests, including skin prick tests and specific IgE blood tests. In some instances, a food challenge may be required as an additional step to definitively establish the diagnosis.

Delayed cow’s milk allergy can be more challenging to diagnose. Also, the symptoms associated with this type of allergy can resemble common infant conditions, such as colic.

To confirm a delayed cow’s milk allergy, patch testing can sometimes be useful, but may have false negative results. In children with only mild symptoms, who are growing well, at Children’s Allergy Doctors we do not always recommend excluding cow’s milk from the infant or maternal diet, so as to maintain some level of cow’s milk tolerance and to minimise the potential nutritional impact.

If symptoms are significant, then the gold standard for diagnosis is the elimination of cow’s milk from the maternal or infant’s diet, followed by reintroduction whilst monitoring symptoms:

  • Elimination: The initial step involves removing all cow’s milk protein from the diet for a defined period, typically spanning 2 to 4 weeks. In the case of bottle-fed babies, this necessitates transitioning to a milk-free formula, while for breastfed infants, it may require the mother to adopt a milk-free diet during this period. It is important that the infant’s mother takes breastfeeding supplements that include calcium and vitamin D, especially if avoiding cow’s milk.
  • Reintroduction: After the designated elimination period (2-4 weeks), cow’s milk-containing foods are reintroduced in a carefully planned manner while closely monitoring for the reappearance of symptoms.

It’s essential to discuss the duration of cow’s milk removal and the entire diagnostic process with a healthcare professional. In cases of delayed cow’s milk allergy, symptoms usually improve when cow’s milk is eliminated from the diet and reemerge when cow’s milk is reintroduced.

What are the symptoms of cow’s milk allergy?

Immediate cow’s milk allergy

Milk allergy symptoms may include:

  • Skin rash identified as hives or urticaria
  • Swelling of the skin, referred to as angioedema, which can occur in various parts of the body, such as the lips or face
  • Abdominal discomfort, nausea, and vomiting
  • Alterations in behaviour

More serious symptoms are often denoted as the ABC symptoms, which can encompass:

  • AIRWAY: Swelling in the throat, tongue, or upper airways, leading to symptoms like throat tightening, a hoarse voice, and difficulty swallowing
  • BREATHING: Sudden onset of wheezing, breathing difficulties, and noisy breathing
  • CIRCULATION: Manifestations such as dizziness, a sensation of faintness, abrupt sleepiness, fatigue, confusion, pale and clammy skin, and loss of consciousness

This more severe reaction to milk is termed “anaphylaxis“. In extreme instances, there may be a dramatic drop in blood pressure, accompanied by weakness, floppiness, and a profound sense of impending catastrophe. This can escalate to a collapse and unconsciousness, and in rare cases, it can be fatal.

Delayed cow’s milk allergy

Symptoms may include:

  • Abdominal discomfort
  • Diarrhoea, which may present with mucous and /or blood
  • Constipation
  • Vomiting
  • Itchy skin
  • Unexplained rash
  • Eczema

Food Protein Induced Enterocolitis Syndrome (FPIES)

FPIES typically manifests in infants with recurrent profuse vomiting commencing approximately 1-4 hours after consuming the responsible food allergen. Additional symptoms include:

  • A pallid complexion
  • Lethargy
  • Weakness or floppiness
  • Diarrhoea
  • Dehydration, which might necessitate immediate medical attention

It is important to note that FPIES does not usually induce skin rashes or respiratory issues and will not respond to antihistamines or adrenaline.

Other varieties of delayed allergic conditions can also be provoked by milk. Additionally, there are non-allergic conditions sparked by milk that do not entail immune system responses, such as lactose intolerance.

How do you treat cow’s milk allergy in babies?

Mild allergic symptoms can be treated with antihistamines for those with immediate cow’s milk allergy. For more serious reactions, two adrenaline autoinjectors should be available at all times if there is a risk of anaphylaxis.

The first should be used as soon as anaphylaxis is suspected, and someone must dial 999 immediately. The second adrenaline autoinjector can be used after 5 minutes if symptoms don’t improve or get worse. It is important that you are supplied with a personalised allergy action plan outlining this.

To ensure you know how and when to use your adrenaline autoinjector, it’s advisable to consult with your GP or allergist for guidance. You can also find helpful information on the manufacturer’s website associated with the specific injector you carry or charities such as Allergy UK or Anaphylaxis UK.

Can milk allergy be cured?

Milk allergy is often outgrown, particularly in children. The likelihood of outgrowing milk allergy depends on the individual, the severity of their initial reaction, the level of their allergy tests, and some people carry milk allergy into adulthood.

Standard treatment for cow’s milk allergy is allergen avoidance, recognition and management of allergic reactions, and periodic allergy testing to assess whether the child is outgrowing their milk allergy. More recently cow’s milk desensitisation offers a more proactive way to treat cow’s milk allergy, by training the immune system to become less allergic to cow’s milk and potentially expediting the resolution of cow’s milk allergy.

Avoiding Cow’s Milk

If you have a cow’s milk allergy, it’s essential to be vigilant when it comes to reading food labels. When dining out at restaurants, takeout establishments, or other food service providers, don’t hesitate to directly inquire with the staff about ingredients. Cow’s milk protein can be present in a variety of foods and ingredients, including:

  • Butter, buttermilk, butter oil, ghee, and margarine
  • Casein and its derivatives (curds, caseinates, hydrolysed casein, calcium caseinate, sodium caseinate)
  • Various forms of cheese, including cheese powder and cottage cheese
  • Cow’s milk and milk products in various forms (fresh milk, condensed, dried, evaporated, milk powder, e.g., infant formulas)
  • Cream-related products like sour cream, crème fraiche, and ice cream
  • Lactalbumin and lactoglobulin
  • Whey and its derivatives (hydrolysed whey, whey powder, whey syrup sweetener)
  • Yogurt and fromage frais
  • Meats can sometimes be infused with cow’s milk

For a complete check list of foods containing cow’s milk and milk alternatives see the Allergy UK PDF Quick Guide to Cow’s Milk Free Diet Information for Babies and Children.

Milk and dairy products constitute a significant portion of the diet for infants and young children, providing essential nutrients such as energy, protein, calcium, iodine, vitamin A, and riboflavin.

These nutrients are vital for healthy growth, development, as well as bone and dental health. Therefore, it is crucial to consult with your GP, health visitor, or another healthcare expert if you suspect that your baby or child might have a cow’s milk allergy.

How can we help at Children’s Allergy Doctors?

Here at Children’s Allergy Doctors we provide a full range of allergy services for all allergy conditions. We aim to be with you every step of the way, from allergy diagnosis through to helping you with food allergy management and more.

We offer food allergy desensitisation (also known as oral immunotherapy) to both baked cow’s milk and fresh cow’s milk. Baked milk oral immunotherapy (OIT) is a treatment programme designed to give increasing amounts of baked milk to your child. The aim of the treatment is to help prevent accidental reactions to baked milk. It may help expedite the resolution of fresh cow’s milk allergy.

Fresh milk oral immunotherapy (OIT) is a treatment programme designed to give increasing amounts of fresh milk to your child. The aim of the treatment is to help prevent accidental reactions to fresh milk. It is not a cure for milk allergy but may help expedite the resolution of fresh cow’s milk allergy.

You and your child will be counselled throughout the programme and will be seen at regular intervals in a consultant-led allergy clinic. Suitability for OIT will be addressed as part of your child’s routine appointment when an allergy diagnosis is made.

If your child is eligible for Oral Immunotherapy (OIT) and you are interested in moving forward, we will create a customised treatment plan. This plan usually involves a series of 3-6 visits, starting with an initial appointment during which the first dose of the allergen will be administered and building up to the maintenance dose which is then maintained daily at home.

If you would like to find out more about cow’s milk allergy or any other aspect of children’s allergies, or book an appointment, please contact our practice team on 0203 146 7721 or email


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