What Is Milk Allergy?


Milk allergy is an unusual immunological response to milk or items containing milk. It is one of the most prevalent food allergies in children. The most common milk that triggers the allergy reaction is cow’s milk, although reactions can also be brought on by milk from sheep, goats, buffalo, and other mammals.  

An allergic reaction typically manifests shortly after an affected individual  consumes milk. There are a variety of mild to severe milk allergy symptoms, such as wheezing, vomiting, hives, and digestive issues.2 In addition, a severe, perhaps fatal reaction called anaphylaxis can also be brought on by a milk allergy.

The primary remedy for treating milk is to avoid the consumption of dairy products.2 Fortunately, most kids outgrow their milk allergy. However, those who do not grow out of it might need to avoid dairy products.

Causes of milk allergy

In cow’s milk, two primary proteins can result in an allergic reaction.

  1. Casein-A substance that is present within the curdled milk’s solid part
  2. Whey-A liquid component of milk that is left behind when milk curdles

One or both milk proteins may cause an allergic reaction. However, due to their inclusion in several processed foods, these proteins may be challenging to avoid. 

Immune system dysfunction is the root cause of all food allergies. When you have a milk allergy, Immunoglobulin E (IgE) antibodies are produced to neutralise the allergen because the immune system identifies some milk proteins as harmful. When you are exposed to these proteins again, your IgE antibodies recognize them and alert your immune system to produce histamine and other chemicals, leading to various allergy signs and symptoms.2

A delayed food allergy, known as food protein-induced enterocolitis syndrome (FPIES), can also be brought on by food allergens. Milk is one of the most common substances that triggers it. Instead of happening immediately after consuming dairy, the reaction (frequently vomiting and diarrhoea) typically occurs hours or even days later.3

Signs and symptoms of milk allergy

Milk allergy symptoms differ from person to person. Quicker symptoms of milk allergy might include:

  • Hives
  • Wheezing
  • Itching or tingling feeling around the mouth
  • Swelling of the lips, tongue, or throat
  • Coughing
  • Shortness of breath
  • Vomiting

The following symptoms may take longer to manifest:

  • Diarrhoea (may contain blood)
  • Stomach cramps
  • Colic (in babies)
  • Runny nose
  • Watery eyes


If you suspect you or anyone around you may  have a milk allergy, you will be required to get some tests. Doctors will ask for several medical histories and run some physical examinations. Moreover, allergy tests such as skin prick tests, specific IgE blood tests, or oral food challenge tests must be done to confirm milk allergy.

Management and treatment options for milk allergy

The main course of treatment for milk allergy is complete avoidance of dairy. The following are several remedies for managing milk allergy:

  1. Dairy elimination: All sources of dairy products, including cow’s milk, goat milk, and any food or beverages that contain milk as an ingredient, must be eliminated
  2. Medications: Antihistamines can be used to treat minor allergic reactions and lessen their symptoms, such as hives, itching, and nasal congestion. However, they do not treat the underlying allergy8
  3. Oral immunotherapy: This treatment may be suggested by allergists in specific circumstances to improve milk proteins tolerance over time progressively. This should only be carried out under the supervision of a doctor9 
  4. Epinephrine Auto-injector: It is essential for people who have a history of severe allergy reactions or anaphylaxis to carry an epinephrine auto-injector such as EpiPen.5 This emergency medication can be self-administered

Risk factors

Several risk factors might contribute to the development of milk allergy:

  1.  Another allergy- Numerous children with milk allergies also suffer from other allergies (e.g., due to the similarities between the proteins in soy and cow’s milk, people with soy allergies may also develop an allergy to cow’s milk)5
  2. Family history- If one or both parents suffer from an allergy, there is a higher chance for children to develop a food allergy
  3.  Atopic dermatitis- Children who suffer from atopic dermatitis are more at risk of developing food allergies, including milk allergy5
  4. Age- Children are more likely to have milk allergies. However, their digestive systems mature as they age, and their bodies are less prone to react negatively to milk


How common is milk allergy?

Milk allergy is one of the most common food allergies, especially in infants and young children. The prevalence of milk allergy varies depending on the population and region. However, it is projected to affect 2% to 3% of young children.

Who is most at risk of milk allergy?

Although it can affect people of all ages, milk allergy is more prevalent in newborns and young children. It frequently manifests early when babies first consume cow’s milk or formula containing cow’s milk proteins. However, most children outgrow their milk allergy by  age  3-5. Nevertheless, the tolerability of cow milk protein must be retested by medical specialists.

How to prevent a milk allergy?

Although no specific method exists to prevent a food allergy, you can reduce symptoms by avoiding the triggering foods. If you have a milk allergy, you should avoid consuming dairy products by analysing food labels thoroughly. Look for casein, which is sometimes hidden in canned tuna, sausage, and non-dairy goods. Moreover, when eating at a restaurant, ask the waiter/waitress about an allergy-specific menu.

Can milk allergy lead to complications?

Unfortunately, milk allergy can sometimes lead to complications such as anaphylaxis (a potentially fatal reaction that can block the airways), which is also caused by peanut allergy. No matter how small the reaction, you should let your doctor know if you or your family members react poorly to milk. 

What are the nutrients substitutes for individuals with a milk allergy?

Due to dietary limitations, people who suffer from milk allergy are often found with nutritional deficiencies like low vitamins and minerals. Therefore, if you have a milk allergy, you need to find alternative nutrient sources of nutrients to maintain a balanced diet. The following are some substitute vitamin and mineral intake options2:

  1. Calcium
    • Green vegetables (kale, broccoli, bok choy, spinach, etc.)
    • Fortified orange juice
    • Tofu made with calcium sulphate
  1. Vitamin D
    • Sun exposure (a healthy amount of sunlight can help the body produce vitamin D)
    • Fatty fish (salmon, tuna, mackerel)
    • Supplements (you should consult a doctor for the correct dosage)
  1. Vitamin B12
    • Fortified cereal
    • Meat substitute
    • Supplements (you should consult a doctor for the correct dosage)
  1. Potassium
    • Bananas
    • Potatoes/sweet potatoes (with skin)
    • Green vegetables (kale, broccoli, bok choy, spinach, etc.)
    • Beans
    • Lentils
  1. Milk alternative for infants
    • Breastfeeding (best nutritional source)
    • Hypoallergenic formulas (the least likely to result in an allergic reaction are formulas based on amino acids)

How are skin-prick tests run?

A liquid containing milk or a milk protein extract is rubbed to your forearm or back during the skin-prick test. A tiny, sterile probe is used to pierce your skin, allowing the liquid to flow in. A raised, reddish welt that appears within 15 to 20 minutes may be an indication of developing an allergy reaction.

Are lactose intolerance and milk allergy the same?

Lactose intolerance and milk allergy are not the same. Lactose intolerance is not an allergy because it does not involve the immune system, but it is an inability to properly digest lactose. When a person has lactose intolerance, their body does not create enough lactase to break down the milk and sugars.7 Milk allergies can result in more acute symptoms, and a severe reaction could be fatal. 

When should I see a doctor?

If you/your kid develops milk allergy symptoms shortly after consuming dairy, you should go to the doctor and get allergy tested immediately. In addition, consult a specialist (allergist) to help aid the diagnosis as soon as possible.


Milk allergy is an immunological reaction to milk or goods containing milk. It is particularly prevalent in infants and children. It can result in hives, wheezing, vomiting, and anaphylaxis, among other mild to severe symptoms. 

The main course of treatment is to avoid dairy products as the protein of cow’s milk is the most triggering factor of developing milk allergy. Moreover, taking antihistamines can aid allergy reactions. Individuals with atopic dermatitis, other food allergies, or a family history of allergies are at higher risk of getting milk allergy. 

Anaphylaxis is one possible complications, and taking an epinephrine auto-injector is always suggested in case of an emergency. Those allergic to milk should seek out different sources of nutrients such as calcium, vitamin D, and vitamin B12 from green vegetables or supplements that do not contain dairy. Moreover, the trigger foods should be avoided, and food labels must be read thoroughly to avoid a reaction. Skin prick testing and oral food challenges can be used to diagnose the allergy. The inability to digest lactose distinguishes lactose intolerance from milk allergy. Consider being tested for allergies if you experience symptoms of a milk allergy.


  1. ‌Edwards CW, Younus MA. Cow Milk Allergy [Internet]. PubMed. Treasure Island (FL): StatPearls Publishing; 2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542243/ 
  2. Skripak, J. M., Matsui, E. C., Mudd, K., & Wood, R. A. (2007). The natural history of IgE-mediated cow's milk allergy. Journal of Allergy and Clinical Immunology, 120(5), 1172-1177. https://doi.org/10.1016/j.jaci.2007.08.023
  3. Bulsa, K., Standowicz, M., Baryła-Pankiewicz, E., & Czaja-Bulsa, G. (2021). Chronic Milk-Dependent Food Protein-Induced Enterocolitis Syndrome in Children from West Pomerania Region. Nutrients, 13(11). https://doi.org/10.3390/nu13114137 
  4. Sardecka, I., Łoś-Rycharska, E., Ludwig, H., Gawryjołek, J., & Krogulska, A. (2018). Early risk factors for cow's milk allergy in children in the first year of life. Allergy and asthma proceedings, 39(6), e44–e54. https://doi.org/10.2500/aap.2018.39.4159
  5. Grissinger, M. (2017). EPINEPHrine for Anaphylaxis: Autoinjector or 1-mg Vial or Ampoule? Pharmacy and Therapeutics, 42(12), 724-725. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5720482/
  6. Ogata, M., Kido, J., & Nakamura, K. (2021). Oral Immunotherapy for Children with Cow’s Milk Allergy. Pathogens, 10(10).https://doi.org/10.3390/pathogens10101328
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Jennifer Grace

Biomedical Sciences, The University of Manchester

My name is Jennifer Grace, and this September marks the beginning of my final year pursuing BSc. (Hons) Biomedical Science studies at the University of Manchester. Born in Indonesia, I embarked on a journey fueled by curiosity. From a young age, my passion for Biology and healthcare framework emerged, propelling my achievements of biological science. Driven by my ardour for scientific exploration, I have actively engaged with various organizations dedicated to environmental and healthcare frameworks. My commitment to advancing science found expression through my participation in the Klarity internship program as an article writer to improve my writing skills, especially scientific writing skills. With each step, I'm unflinchingly dedicated to blending my affection for science with a significant feeling of direction for my career.

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