Milk allergy / milk protein allergy


Milk allergy, also known as cow's milk allergy or cow's milk protein allergy, is an immediate type of food allergy (type 1). This means that the allergic reaction occurs within seconds to minutes and a delayed reaction is also possible after 4 to 6 hours.

The frequency of a milk allergy in infancy and toddler age is around 2 to 3% of the population and is often evident in the first months of life after weaning. The majority of children develop tolerance in the first few years of life, which means that they are then able to drink cow's milk.

Adults can also develop a milk allergy. Women are more often affected than men and the allergy occurs between the ages of 20 and 50.

The cow's milk allergy is often confused with lactose intolerance, as both diseases have similar symptoms, but their causes are clearly different.

Milk allergy vs. Lactose Intolerance - What's the Difference?

Milk allergy and lactose intolerance can cause similar symptoms. Abdominal pain, flatulence, diarrhea and a feeling of fullness can occur with both diseases, which is why cow's milk allergy can often be confused with lactose intolerance, i.e. milk sugar intolerance.

The milk allergy is caused by the immune system, which incorrectly considers the milk proteins to be foreign and dangerous.

In contrast, the cause of lactose intolerance lies in the intestines. There is little or no lactase in the intestinal mucosa. Lactase is a digestive enzyme that breaks down milk sugar in food. The milk sugar lactose consists of the grape sugar (glucose) and galactose (Slimy sugar). The intestine can only absorb the sugar molecules if they have previously been split into the two small sugars by the lactase.
In the case of lactose intolerance, the lactose reaches the large intestine unprocessed, where it is absorbed and fermented by intestinal bacteria. This creates gases that lead to flatulence and lactic acid. Lactic acid is osmotically active, which means that it causes water to flow into the intestines. The fluid in the intestinal contents creates very fluid stools, which is why those affected often suffer from diarrhea. Overall, milk allergy and lactose intolerance both often result in gastrointestinal complaints, but the causes and treatment options differ greatly from one another.

Read more about this under Symptoms of lactose intolerance


In the event of an allergic reaction, the immune system can no longer differentiate between harmful and harmless substances and reacts to a harmless substance by producing antibodies, which in this case are directed against the milk protein.
The exact causes why some babies develop a milk protein allergy are not yet fully understood. Milk contains 25 different proteins that can act as allergens, which means that they can be recognized as foreign and cause allergy symptoms. The proteins casein, β-lactoglobulin or α-lactalbumin are often responsible for this.

However, it is known that babies who are previously exposed to protein from cow's milk have a significantly higher risk of developing this allergy. This can be explained by the fact that the immune system of infants is still developing. It is therefore not yet able to differentiate well between exogenous and harmful substances as well as exogenous but harmless substances. The immune system learns this over time. That is why it is relatively common for milk protein allergies that the allergy disappears with increasing age.

Another cause of a milk protein allergy is most likely in the genes. If the parents are affected by a milk protein allergy, their offspring also have a higher risk of developing this type of allergy.

I recognize a milk protein allergy by these symptoms

The symptoms of a milk allergy can be manifold. Most of the time, the skin, gastrointestinal tract, and respiratory tract are affected. In acute cases, the cardiovascular system can also be affected, with the most severe form of allergic reaction being anaphylactic shock, which is life-threatening.

Classic gastrointestinal complaints are nausea, vomiting and abdominal pain.
The allergy can cause tiredness, fatigue, and restlessness, and can lead to inconsolable crying in young children and infants.
Possible respiratory problems in the case of a milk allergy are narrowing of the bronchi, larynx swelling (Laryngeal edema), allergic rhinitis up to bronchial asthma.

In severe cases, systemic reactions of the body occur in the context of the milk allergy, including cardiovascular problems, breathing problems and anaphylaxis, in which several organ systems react to the allergy and a state of shock occurs.

In the case of neurodermatitis skin changes in particular, a food allergy is suspected. Most children with eczema also have a food allergy. In infancy, milk is actually the most common allergy trigger; in older children, eggs, soy, nuts and certain fruits also play a role. It is therefore worth visiting a children's allergist if the symptoms mentioned above persist for several months.

to cough

As part of allergy-related respiratory problems, milk allergy can lead to swelling of the larynx, breathing difficulties, a runny nose and cough.
Allergic coughing with milk allergy is a relatively common symptom, as the immune system often increases more mucus in the bronchi as a reaction to the allergenic substances. The body tries to cough up the foreign matter, so to speak.

More on this: Cough if you have an allergy

Symptoms of the skin

Common skin problems associated with milk allergy include hives (Urticaria), Skin redness (Erythema), Itching and eczema on contact with the allergen, i.e. an inflammatory rash on dry skin. The skin complaints can vary in severity.

Read more about this at:

  • Red spots on the body - causes and treatment
  • Itchy Rash - What Disease Is It?

skin rash

The skin often reacts particularly quickly to allergies, it serves the immune system as a “helper” and “ambassador”. A rash is a common symptom of a milk protein allergy.

Mostly this forms in the context of atopic eczema. At the beginning there is reddening of the skin with small blisters and increased flaking. The skin areas have red to brownish or white spots. Pips and garlands may form, which can be flat and raised. Wheals often occur in so-called hives, they are small, soft, light to pink swellings of the skin. The skin is also very dry.
The children suffer from excruciating itching. The diagnosis of atopic eczema or neurodermatitis can thus be made relatively easily. In babies, the scalp, face, and extensor sides of the extremities are most affected. As the children get older, the typical rash is more likely to be found on the elbows, back of the knees and neck area.

Read more about this at:

  • Rash from milk
  • You can recognize neurodermatitis by these symptoms


As part of a rash caused by a milk allergy, pimples and pustules can appear, i.e. small pus vesicles relatively superficial under the skin.
There is no scientifically proven link between the occurrence of pimples in milk allergy. However, pimples can be a sign of the skin's overreaction to the allergen, the milk proteins, as the allergy symptoms can vary in different people.

You may also be interested in this topic: How to Get Rid of Pimples

What can you eat?

It is important to avoid milk in your diet. This not only includes cow's milk, but also goat, sheep and mare's milk. Even soy milk should be consumed with caution, as soy can also often cause allergies.
But not only obvious dairy products should be removed from the menu, many products that you would not think so at first glance should also not be eaten. It is important to note that many finished products also contain hidden milk components. These include bread and special baked goods, rusks, muesli, milk rolls, ready-to-eat pasta meals, sausage products, etc. All of these products must be avoided.

So that you don't accidentally consume something with milk protein, it is worth taking a look at the list of ingredients on the packaging. Anything without the following ingredients may be consumed:

  • milk
  • Whey protein
  • Lactoglobuin
  • Lactalbumin
  • and casein

For babies you have to choose a special formula that can be prescribed by the doctor and specially ordered through the pharmacy.

You might also be interested in this topic: Diet for people with lactose intolerance

These cross allergies exist

What is a cross allergy? This question is actually very easy to answer: Some allergens are so similar in structure that the immune system of the allergy sufferer cannot differentiate them.

Therefore, over time, allergies to other substances that are very similar to the original allergen on a molecular level develop. This can also only be the case in the further course of the disease.

For cow's milk protein allergy, additional milk protein from goat, sheep or mare's milk can also trigger allergic symptoms. But there are also cross-reactions with Almond milk, oat milk and rice milk are described. Soy milk too can trigger an allergy, whereby soy is free from any components of cow's milk, but is itself a highly potent allergen, i.e. Soy is a substance that itself often causes allergies.

You can find more on the subject herer: The cross allergy

How dangerous can the milk protein allergy be?

A milk protein allergy can be particularly dangerous for infants if it is not recognized. The babies then suffer from severe diarrhea over and over again.

The massive loss of fluid in particular is dangerous for babies and toddlers, as it quickly leads to dehydration (Desiccosis) leads. It is therefore important that parents look out for signs of acute dehydration in children with diarrhea. These include dry tongue, sunken eyes, or a restless baby. In the vast majority of cases, however, a cow's milk allergy is not an acutely life-threatening clinical picture, mostly the children and also the parents suffer from the chronic digestive disorders.

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  • Diarrhea in the baby
  • Dehydration in children


Determining a milk protein allergy is not easy - especially since the symptoms are often so different.
Most of the time, digestive problems are in the foreground, but severe neurodermitic rashes can also occur. Not all sufferers show these symptoms immediately after ingesting food, and some only appear after several days.

It is typical of an allergy, however, that the symptoms usually improve suddenly if the triggering agent is omitted. Therefore, you will ask those affected to refrain from dairy products for 14 days. For this period, babies can be prescribed a special formula that does not contain milk protein.

You can also do an allergy test in the blood or on the skin carry out. However, one should know that if the allergy test is negative, a milk protein allergy can still be present. It is therefore ultimately decisive for the diagnosis whether the symptoms are significantly improved, if not even completely, by omitting the milk.

If the parents or siblings suffer from allergic diseases such as neurodermatitis, asthma or hay fever, the risk of allergies for the child concerned is significantly higher. As a rule, parents are also asked to keep a food diary for the affected child.

More on this topic: Testing for a food allergy

What tests are there for a milk allergy?

A skin test, for example the prick test, is done to provide initial indications of a milk allergy.
The skin is scratched in a small area with a lancet and the allergen is brought into the skin. One observes whether a reaction in the form of red wheals occurs. The prick test is usually painless. This test can be done for many allergies, for example pollen or animal hair allergies.

In addition, there are blood tests which, as the next step, examine whether there is actually an immunologically mediated allergy to milk proteins. The RAST test (Radio-Allergo-Sorbent Test) examines the presence of specific IgE antibodies in the child's blood. However, a positive test does not always have to be a clinically relevant allergy. The results of the blood test help isolate suspicious triggers of the allergy.

Another possibility for testing is a milk-free elimination diet, in which the child completely dispenses with milk in their food. After a certain period of time, a provocation takes place, which means that the child is fed small amounts of milk in order to observe whether there is an allergic reaction to the milk intake. The dairy-free elimination diet serves the pediatrician on the basis of the preliminary examinations as a reliable clarification of the allergy if a milk allergy is suspected.

Read more about this under Allergy diagnostics

Treatment and therapy

The therapy for a milk allergy is based on a consistent change in diet. In particular, children with milk allergies need a diet that is completely free of milk and milk products in order to enable the child to develop without problems. There are no drugs or other therapies that can treat the cause of the disease. The only thing left for those affected is to radically forego products with cow's milk or cow's milk protein.

This is of course a challenge, especially for babies. Despite these dietary restrictions, the baby must be supplied with all the important nutrients. Most of the time, the allergy disappears with age, as the immune system continues to develop. Therefore, one often speaks of an elimination diet, because you only have to do without these products for a limited period of time. There are now very good cow's milk-free substitute foods for babies. They are fed like normal baby food. However, the special food is prescribed by the doctor. It ensures that the infant grows and thrives without suffering from the serious allergy symptoms.

One possible therapy attempt for cow's milk allergy is desensitization. Desensitization, also allergy vaccination or immunotherapy called, is supposed to treat the overreactions of the immune system to the milk protein. In practice, it looks like the patient is given milk in increasing doses. If the allergy is particularly severe, start with a mixing ratio of milk and e.g. Water from 1: 100 on, later 1:10 or drop by drop. Those affected take milk daily even after desensitization, so that the habituation effect is not lost.

In the classic form of desensitization, injections are given weekly in which the milk concentration increases. This happens over 16 weeks until the so-called maintenance dose is reached. The patient then receives a monthly injection with the maintenance dose for three years in order to maintain the habituation effect.

In addition, there is short-term desensitization, in which the dose of milk is increased much faster in the introductory phase. With the Ultra-Rush desensitization, the dose is increased even more quickly in order to get used to the milk quickly. In any form of desensitization, once the maintenance dose has been reached, injections are given monthly for three years.

Which doctor is responsible for this?

Once you have recognized the allergy-related symptoms, you should definitely see a doctor to analyze the symptoms and start appropriate therapy. In general, the family doctor is the most important contact person for milk allergies, as he knows the previous course of the disease and the medication. The pediatrician is the first point of contact for children.

After the first check at the family doctor or pediatrician, a specialist colleague can be called in, depending on the symptoms. An allergist is a doctor who has completed additional training on the subject of allergies. An allergist can help if the family doctor or pediatrician cannot find a suitable therapy for the milk allergy.
ENT doctors can be helpful if symptoms arise in the nasopharynx and pulmonology, especially in asthma. Ophthalmologists or gastroenterologists can help if specific complaints of the eyes or the gastrointestinal tract are not easily treatable.

In general, however, the family doctor or pediatrician should be made aware of the milk allergy as the first point of contact. In case of doubt, the family doctor or pediatrician can issue referrals to other specialists.


The prognosis for a cow's milk allergy is good. Most of the time, it's just a temporary problem.
In contrast to other allergies, there is a high probability that it will grow together with age. Even those who suffer from a milk protein allergy as a baby have a good chance of being able to eat dairy products again as a school child. It is important that from the age of two onwards, regular exposure tests are made under medical supervision.

Course of disease

A cow's milk allergy usually develops in infancy or childhood.
During this time, the immune system is not yet fully developed and reacts with an excessive reaction to the proteins in milk. Therefore, the symptoms are particularly bad during this time. If a cow's milk allergy is then diagnosed, it is important that the diet is consistently switched to foods free of milk protein. Then the symptoms improve quickly.

The immune system continues to develop with age. Therefore the good news for all concerned is up to 90% of children can tolerate milk and dairy products again by school age. Regular exposure tests should be carried out under medical supervision.

Milk allergy: special features in babies

It is mainly babies who are affected by a milk protein allergy. However, unlike adults, the main component of their diet is usually milk.

Breast milk is still considered the best nutrition for the baby. Indeed, babies who come into contact with other milk early on have a higher risk of developing a cow's milk allergy. However, breastfed babies can also develop a cow's milk allergy. The babies come into contact with cow's milk protein through the mother's diet. So the child does not have an allergic reaction to breast milk. The mother can certainly continue to breastfeed. However, she then has to consistently avoid milk and dairy products in her diet. As a result, the babies' symptoms usually improve very quickly. Otherwise you can also switch to a special milk protein-free formula diet. The doctor prescribes this special food. It is well tolerated and provides the infant with all essential nutrients.

A milk allergy shows up significantly differently in babies than in adults and is not always easy to recognize. Skin problems, gastrointestinal complaints and respiratory problems can occur. Every child has different signs of a milk allergy.

  • In infants, a milk allergy can manifest itself in the form of restlessness, inconsolable crying and insomnia, which is often dismissed as "harmless".
  • In breastfed babies, allergic reactions can occur that are not directed against breast milk but with cow's milk protein from the mother's diet.

Most children develop a tolerance towards milk protein in the first months / years of life. Nevertheless, you should inform your doctor if you have symptoms in order to enable the baby to develop without problems.

Find out more about the topic here:

  • Baby's allergy to cow's milk
  • Feeding the baby - the recommendation for infants