Cow's milk allergy

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A glass of cow's milk
Type I allergic reaction

Cow's milk allergy also cow's milk protein allergy is a food allergy of type I (immediate type). In Central Europe, due to the local eating habits, cow's milk is usually the first foreign protein that an infant comes into contact with in the form of baby milk. The sensitization usually takes place via the oral route with the diet.

The disease is often mistaken for lactose intolerance . Both diseases are similar in many symptoms , but have completely different causes.

Frequency / incidence

The frequency of a cow's milk protein allergy in infancy and toddler age is around 2 to 3% of the population. It usually manifests itself in the first months of life, often after weaning the infant with the introduction of infant formula or with the introduction of milk as part of complementary food. In rare cases, even fully breastfed children develop a cow's milk allergy, as cow's milk allergens from the maternal diet pass into the breast milk and can sensitize the infant in this way.

forecast

The prognosis is favorable, around 75% of the children affected show a tolerance development by the age of two and 90% by school age. Adults are less likely to have a cow's milk protein allergy.

causes

In the case of an allergy, the child's immune system classifies the milk protein as "foreign" or "dangerous". Contact with the supposed foreign substance (= allergen) triggers an immunologically mediated overreaction of the immune system, which leads to symptoms of an allergy. Milk contains 25 different proteins that can act as allergens , with various caseins , β-lactoglobulin (β-LG) and α-lactalbumin causing allergic reactions. Severe cardiovascular complaints, which can be associated with life-threatening asthma attacks and anaphylaxis , occur less often . A cow's milk allergy encompasses all immunological mechanisms that take place via IgE- mediated reactions (IgE cow's milk / cow's milk protein allergy) and other immunoglobulins (non-IgE cow's milk / cow's milk protein allergy), in rare cases T-lymphocytes . Allergic reactions can affect different organs. This includes the skin, the gastrointestinal tract and the respiratory tract.

One new suggestion is that disruptions to the microbiome in the gut could cause or promote cow's milk allergy.

Allergenic components of cow's milk protein

Cow's milk protein is a mixture of different protein fractions. These include a.

  • casein
  • β-lactoglobulin
  • α-lactalbumin
  • Bovine serum albumins
  • Lactoferrin
  • Immunoglobulins.

Each individual fraction can have a potentially allergenic effect, with most allergies being triggered by casein, β-lactoglobulin and α-lactalbumin and, more rarely, by the other protein structures. Cow's milk is closely related to the milk of other animal species and, due to similar protein structures, most people with a cow's milk allergy also react to goat, sheep and mare's milk. These are therefore not suitable for feeding children with a cow's milk allergy.

Forms of allergy

With regard to the reaction time, a distinction is made between so-called immediate type allergies and late type allergies. Immediate Type I allergies are characterized by the fact that the symptoms appear immediately or within two hours of contact with the allergen. In addition to immediate reactions, about 50% of the children affected have significantly delayed reactions (late reactions). In the case of late reactions, symptoms only appear up to 48 hours after ingestion of the allergen. The symptoms in question very rarely break out after a week. Immediate reactions are mostly allergic reactions mediated by so-called IgE antibodies (immunoglobulin E). Upon contact with the allergen, the organism forms specific proteins (immunoglobulins), the task of which is to recognize foreign substances in order to bind and fight them. In allergic reactions to food allergens, the body produces specific IgE antibodies. As a result, inflammatory messengers are released, which trigger inflammatory reactions that take the form of allergic reactions in various organ systems, such as B. the skin, gastrointestinal tract, and airways manifest. Recording the total IgE and the specific IgE antibodies in the blood is an important part of allergy diagnostics. Late-type allergies have a special position among allergic reactions. These allergies are usually not mediated by antibodies, but by other cellular immune mechanisms. Therefore no IgE antibodies are detectable in the blood. They are referred to as non-IgE-mediated allergies and can only be detected by means of a milk-free elimination diet with subsequent provocation. Blood tests are usually negative in this form and these late reactions are not recorded even with skin prick tests. The Atopy Patch Test, which can only be read after 48 hours, is no longer recommended for practice. Overall, cow's milk allergy encompasses all immunological mechanisms that take place via IgE- mediated reactions (IgE cow's milk / cow's milk protein allergy) and other cellular immune mechanisms, such as in non-IgE-mediated allergies (non-IgE cow's milk / cow's milk protein allergy).

Symptoms

Symptoms, extent and severity of symptoms can be very diverse. The skin, the digestive tract , the respiratory tract and, in acute cases, the cardiovascular system are usually affected . Complaints can occur individually, but there are often combined forms of complaint. The symptoms can be mild to severe. The most severe form of allergic reaction is anaphylactic shock. Within seconds and minutes, life-threatening complaints arise that require immediate intervention. Most allergies, however, are not life-threatening or life-shortening, but they significantly reduce the quality of life and the well-being of those affected. The leading skin conditions include:

  • Urticaria (hives)
  • Erythema (reddening of the skin)
  • itching
  • Eczema formation, worsening of eczema after contact with allergens

Characteristic gastrointestinal complaints are:

  • nausea
  • Vomit
  • stomach pain
  • Oral and perioral swelling
  • Recurrent diarrhea with signs of malabsorption
  • Enteropathies
  • Bloody, slimy stool indicating allergic colitis
  • Increased spitting
  • Food refusal
  • Failure to thrive
  • Colic
  • Constipation
  • Gastroesophageal reflux
  • Eosinophilic esophagitis

Possible respiratory problems are:

  • Bronchial obstruction
  • Laryngeal edema (larynx swelling)
  • Allergic rhinitis
  • bronchial asthma

Non-specific symptoms:

  • Inconsolable screaming
  • Tiredness / exhaustion
  • Restlessness

Systemic reactions:

  • Cardiovascular problems
  • Breathing problems
  • Anaphylaxis

Differentiation from milk sugar intolerance (lactose intolerance)

Due to similar complaints (abdominal pain, flatulence, diarrhea, bloating), cow's milk allergy is often confused with lactose intolerance (= milk sugar intolerance). Both diseases can cause similar symptoms, but have different causes and therefore require different dietary treatments.

diagnosis

Any suspicion of a cow's milk allergy should be checked by a pediatrician. In order not to endanger an optimal supply of nutrients or to unnecessarily restrict the choice of food, the diet should not be changed on mere suspicion. Various examinations are required for a reliable result. This includes:

  1. Detailed discussion ( anamnesis )
    It is about the previous development of the child, the diet, family allergy disposition. Are family members (parents, siblings) suffering from an allergic disease such as B. Atopic dermatitis, asthma or hay fever, the risk of allergies for the child is increased.
  2. Food
    diary Parents make a note of all food and beverages consumed over 5–7 days, as well as the type, extent and time of the symptoms observed. These records can be used to further isolate suspicious triggers.
  3. Skin test, e.g. B. Prick test .
    The skin is scratched with a small lancet and the allergen is introduced into the skin and a reaction in the form of red wheals is observed. These results provide initial indications that must be confirmed by further investigations.
  4. Blood tests, e.g. B. a RAST test .
    The total IgE value and the presence of specific IgE antibodies in the blood are determined. A milk-free elimination diet with subsequent provocation confirms whether positive values ​​are clinically relevant. These results help to isolate suspicious triggers, but the presence of non-IgE-mediated allergies based on a different cellular mechanism should always be considered. Therefore, further examinations are indicated for further clarification. The determination of the IgG has no diagnostic value and is not relevant for clarifying a suspicion.
  5. Dairy-free elimination diet with subsequent provocation
    On the basis of the preliminary examinations mentioned above, the milk-free     elimination diet allows a reliable clarification of suspected cow's milk allergy. The basis of this examination module is the targeted and strict avoidance of the suspicious trigger in order to determine how the symptoms change during the trial change in diet. For this purpose, breastfeeding mothers eat completely without milk and dairy products for up to two weeks. Children who are not breastfed receive a special milk-free, non-allergenic formula instead of conventional infant formula. The doctor decides which food is best for the child and determines the diet for each child individually. Parents write down any reactions or changes their child has during the change in diet in a diary. If the symptoms improve or go away completely, a cow's milk allergy is likely.

Oral provocation should always follow for a reliable assessment. For this purpose, small amounts of milk are reintroduced into the mother's diet or small amounts of the original cow's milk formula are fed again under medical supervision. If the known complaints reappear, the suspicion is confirmed and the doctor believes that the dairy-free diet will be continued for the next 6-18 months. In the case of severe reactions in the past, you can dispense with renewed exposure to the allergen in order to avoid unnecessary exposure of the child. The attending physician decides on the exact procedure. Since it is not possible to estimate with certainty which reactions are to be expected in the event of renewed contact with the allergen, the provocation should always be carried out under medical supervision. Depending on the extent and severity of the symptoms that have arisen, the provocation can be carried out on an outpatient basis in the pediatrician's practice. If there is a high risk of anaphylaxis, testing under inpatient supervision is indicated. The treating pediatrician determines the exact procedure. If symptoms do not improve during the elimination diet, a cow's milk allergy is unlikely. A more detailed diagnosis takes place here. If necessary, the referral is made to a specialist.

therapy

The essential basis of the treatment is a consistent change in diet. For a symptom-free development, a diet completely free of milk and dairy products is necessary. Various methods are available for treating cow's milk allergy. The most widely used is desensitization . The patient is given milk in steadily increasing doses. In severe cases of cow's milk allergy, this is given either in a solution (starting with a mixing ratio of 1: 100 and later 1:10) or in drops. The dose of milk administered is increased until the amount of 250 ml is reached. Even after the desensitization has taken place, the patients should consume milk daily, otherwise the habituation effect can be lost again. If the measure just described does not have any effect, only the strict avoidance of the triggering substances is possible.

Breastfeeding with a cow's milk allergy

Children with cow's milk allergy can also be breastfed as long as the mother is on a milk-free diet. Since allergens from maternal nutrition can be found in breast milk, a consistent change in diet is necessary.

Special foods for nutrition in case of cow's milk allergy in infants and toddlers

Milk and milk products are valuable suppliers of nutrients in infant and young child nutrition and make a significant contribution to needs-based supply. Children with a cow's milk allergy require adequate and safe substitute food for their age. There are specially formulated special foods for this purpose. A distinction is made between two basic types: These include the so-called extensive hydrolysates (eHF) and the foods that are based on non-allergenic amino acid building blocks (AA). The abbreviation "eHF" stands for "extensively hydrolyzed". This means that most of the protein has been split into tiny pieces. This measure largely reduces the allergenic properties of the protein. eHF special foods are well tolerated by many children. However, they still contain residual allergens which can still cause symptoms in some children (e.g. in children with non-IgE-mediated forms of allergy). The non-allergenic foods (AA) contain protein in the form of amino acids. Amino acids are the smallest building blocks of a protein. Since they are free from any constituents of cow's milk, they are considered non-allergenic. As a result, AA foods do not trigger any allergic reactions and ensure reliable results and a high level of therapy safety. If children are not completely symptom-free after switching to an eHF diet, switching to an amino acid-based diet may be indicated in consultation with the doctor. Especially in children with non-IgE-mediated gastrointestinal disorders, an exclusive diet with amino acid-based infant formula (AAF) has been shown to be more effective than an elimination diet with external hydrolyzate, since complete allergen elimination is only guaranteed with AAF. The doctor decides which food is best for each child.

Alternative diets

Soy drink

Soy-based baby foods, soy drinks and soy products are allergy-related. They also have a high isoflavone content. These are herbal substances with hormone-like effects. Since the effect of these substances on the metabolism of an infant has not yet been conclusively clarified, the Federal Institute for Risk Assessment (BfR) comes to the conclusion: “Infant formula and follow-on formula made from soy protein should only be given if there are medical reasons, and then only under medical supervision. ”This is why soy-based baby foods or products are neither suitable for the prevention nor for the treatment of babies with a cow's milk allergy.

Milk from goat, sheep, mare, etc.

Goat, sheep or mare's milk are not a suitable substitute for an existing cow's milk allergy. Scientific studies have shown that children generally also have an allergic reaction to these types of milk.

Vegetable alternatives: rice, oat and almond drink

Due to their inadequate nutritional composition, these products are not suitable as the sole substitute for infants and young children. Their composition is not sufficiently adapted to the needs of babies. From a kitchen point of view, they can be used as a liquid substitute in recipes, e.g. B. in baking, can be used. Since rice drink contains inorganic arsenic compounds, which are classified as harmful to health, based on recent studies, rice drink should only be consumed occasionally in moderation as part of an otherwise balanced mixed diet.

HA foods

The abbreviation "HA" stands for hypoallergenic. The name is based on the fact that the protein was split into smaller pieces. In smaller pieces, the protein is less likely to trigger allergies. HA foods are therefore recommended as a preventive measure for non-breastfed infants with a family-related increased risk of allergies. Your job is to avoid the development of an allergy. But HA foods are not suitable for treating an already existing allergy, because the protein components they contain are allergenic. They are not sufficiently safe for affected children.

Alternative treatments

Based on the data available so far, the elimination diet is currently the best treatment option for children with food allergies. I.e. In the case of cow's milk allergy, switching to a dairy-free diet is still the first treatment option. There is no scientifically proven evidence of effectiveness for alternative forms of treatment.

Oral provocation to regularly check whether the diagnosis is up to date

In terms of quality of life, dietary restrictions should only be observed for as long as necessary. In view of the good prognosis, whether the diagnosis is up to date should be checked at regular intervals. The pediatrician will determine the exact period. In principle, the provocation should always take place under medical guidance. In the case of clear complaints, especially if previously shock-like complaints occurred, the provocation should be carried out in the hospital. If the symptoms are milder, the provocation can be carried out in the pediatrician's office. In individual cases, the test can also be carried out at home in consultation with the doctor. The exact procedure always follows the instructions of the doctor. For a reliable assessment, a conventional baby food or normal cow's milk is used during the test, depending on the age. Starting with the smallest amounts, the portions are gradually increased at regular intervals (increased every 20 minutes) until a full drink portion (approx. 150 ml) has been reached. Meanwhile, the child is carefully observed. In order to avoid unnecessary stress, the provocation is stopped as soon as clear symptoms arise. If all portions are well tolerated, testing will continue. The child should always be observed because of possible late reactions. As a further safeguard, the full amount (approx. 150 ml) is given again as a single dose the next day, provided that all portions are well tolerated. It is not uncommon for allergic reactions to appear in practice. The second dose is therefore essential for a reliable diagnosis. Practice shows that milk and dairy products are often only cautiously introduced into the diet after the allergy has been proven to have disappeared because parents still feel unsafe and the children first have to get used to the new foods. But to support the existing tolerance and in terms of an optimized mixed diet, milk and dairy products should be consumed regularly in amounts appropriate for children.

literature

  • P. Chatchatee, KM Järvinen, L. Bardina, K. Beyer, HA Sampson: Identification of IgE- and IgG-binding epitopes on alpha (s1) -casein: differences in patients with persistent and transient cow's milk allergy . In: J. Allergy Clin. Immunol. tape 107 , no. 2 , February 2001, p. 379-383 , doi : 10.1067 / may 2001.112372 , PMID 11174208 .
  • P. Chatchatee, KM Järvinen, L. Bardina, L. Vila, K. Beyer, HA Sampson: Identification of IgE and IgG binding epitopes on beta- and kappa-casein in cow's milk allergic patients . In: Clin. Exp. Allergy . tape 31 , no. 8 , August 2001, p. 1256-1262 , PMID 11529896 .
  • U. Schulmeister, H. Hochwallner, I. Swoboda u. a .: Cloning, expression, and mapping of allergenic determinants of alphaS1-casein, a major cow's milk allergen . In: J. Immunol. tape 182 , no. June 11 , 2009, p. 7019-7029 , doi : 10.4049 / jimmunol.0712366 , PMID 19454699 .
  • S. Koletzko, B. Niggemann, F. Friedrichs, B. Koletzko: Consensus paper : Procedure for infants with suspected cow's milk protein allergy. In: Allergo. No. 19, 2010, pp. 529-534.
  • Y. Vandenplas, M. Brueton, C. Dupont, D. Hill, E. Isolauri, S. Koletzko, AP Oranje, A. Staiano: Guidelines for the diagnosis and management of cow's milk protein allergy in infants. In: Arch Dis Child. No. 92, 2007, pp. 902-908.
  • DJ Hill et al. a .: The efficacy of amino acid-based formulas in relieving the symptoms of cow's milk allergy: a systematic review . In: J. Clin Exp Allergy . No. 37 , 2007, p. 808-822 .

Web links

Individual evidence

  1. ^ Matthias Besler, Philippe Eigenmann, Robert H. Schwarzt: Cow's Milk (Bos domesticus). In: Internet Symposium on Food Allergens. 4 (1), (2002), pp. 19-106. food-allergens.de (PDF)
  2. ↑ Ania Muntau: Intensive Pediatrics Course . Elsevier, Urban & Fischer-Verlag, 2007, ISBN 978-3-437-43391-7 , pp. 359 ff . ( limited preview in Google Book search).
  3. ↑ Cathryn R. Nagler, Roberto Berni Canani, Dionysios A. Antonopoulos, Jorge Andrade, Lorella Paparo: Healthy infants harbor intestinal bacteria that protect against food allergy . In: Nature Medicine . January 14, 2019, ISSN  1546-170X , p. 1 , doi : 10.1038 / s41591-018-0324-z ( nature.com [accessed January 19, 2019]).
  4. ↑ milk. Scientific elaboration on milk allergy on: alles-zur-allergologie.de
  5. ↑ Federal Office for Risk Assessment, press information 27/2007 of November 19, 2007