Allergy to Milk: Risk Factors, Symptoms and Treatment


  1. Introduction
  2. Allergy VS Intolerance
  3. Symptoms and Complications
  4. Risk Factors and Treatment
  5. Special Milks


In this article we will talk about milk allergy , or an immune- mediated hypersensitivity to the proteins contained in this food.


First, we will differentiate it with respect to the condition of intolerance , which instead concerns lactose .

We will then present the possible symptoms and complications of exposure to the antigen , as well as the risk factors and treatment , with specific reference to special milks for allergy sufferers.

Allergy VS Intolerance

Allergy to milk proteins or lactose intolerance?

Cow’s milk allergy is the most widespread food sensitization in the first years of life (2-3% of children); it tends to resolve with the maturation of the digestive tract during growth and only persists in adults in 0.5% of cases.

From the second childhood onwards, however, the most common allergens are fish , crustaceans , peanuts and nuts .

This allergic form has nothing to do with milk intolerance, which is common especially in adulthood and the elderly.

People who suffer from milk allergy develop antibodies against some of its proteins ; for this reason, after an initial asymptomatic exposure , ingesting even very small quantities of this food or its derivatives is sufficient to trigger a potentially serious allergic reaction .

It is curious to note that, thanks to digestion , dietary proteins undergo a modification already at the gastric level (by denaturation). Only in the intestine , however, are they totally demolished by the enzymatic action of the pancreas and the brush border .

We know that allergies are not all the same; they exist of different severity and it seems that this correlates – in addition to the type of immune mediation – also to the length of the peptide sequences recognized as antigen. The shorter these sequences (low molecular weight ), the higher the sensitivity.

Lactose intolerance , on the other hand, is a disorder due to the lack of an enzyme, lactase , necessary to digest the typical sugar of milk and dairy products ; the severity of symptoms is dose-dependent and there is no involvement of the immune system .

Symptoms and Complications

Symptoms and complications of milk allergy

The clinical manifestations of milk allergy appear a few minutes to a few hours after the consumption of the food or its derivatives. Symptoms, more often not too severe, are divided into early and late.

The fastest manifesting form of milk allergy, even at very small antigen dosages, is IgE mediated.

Although rarely , already at an early stage, milk allergy can cause a serious complication called anaphylaxis .

It should be noted that children allergic to cow ‘s milk are more likely to develop other allergic forms, such as that to eggs , soy and peanuts or hay fever (a form of allergic rhinitis triggered by contact with grass pollen, hair pets or other substances).

Early symptoms

Less severe: digestive problems , vomiting , hives and difficulty breathing ( dyspnoea ) .

Late symptoms

Diarrhea , abdominal colic , blood in the stool , itchy rash (often localized around the mouth), cough andexcessive tearing .

What is anaphylaxis?

Anaphylaxis, or anaphylactic reaction, is a very dangerous condition that requires quick medical intervention.

Considered the most serious allergic complication, it is characterized by acute symptoms – such as difficulty breathing , intense itching , redness in the face and pressure drop to the point of collapse – which arise early after contact with the allergen (in this case following the intake of milk proteins ).

Symptoms of lactose intolerance

Symptoms of lactose intolerance appear a few hours after consuming milk or other foods rich in lactose , are localized in the digestive system and typically include intestinal swelling , flatulence and diarrhea.

They can also be atypical, affecting areas not related to digestion. If ignored, it can lead to malnutrition and growth failure in infants and children.

Risk Factors and Treatment

Risk factors for milk allergy

Risk factors for milk allergy include familiarity with this or other allergic forms, atopic dermatitis , formula feeding ( with rare exceptions, there are no cases of breast milk allergy ) and age (incidence tends to regress already in the second childhood, with the maturation of the digestive system ).

Treatment of milk allergy

Given the widespread presence of milk and its proteins in commonly used food products , allergic manifestations are quite frequent.

Milder ones can be attenuated by oral therapy based on antihistamines , while in the presence of anaphylaxis an injection of adrenaline may be necessary .

As with all other forms of sensitization, the allergic reaction can only be prevented by avoiding contact with the allergen; consequently it is necessary to exclude any source of milk and its derivatives from the diet.

In case of familiarity, extreme caution is advised in introducing milk other than maternal milk to the baby. In this sense, breastfeeding until weaning is considered a protective agent against allergic complications.

In the nutrition of the allergic infant it is possible to make use of special milks , which we will discuss in the next paragraph.

To know more:Medicines for the treatment of milk allergy

Special Milks

Special milks for milk allergy sufferers

Specific hypoallergenic formulations have been studied for feeding infants .

These formulas are produced using quite complex technologies (enzymatic reactions, filtration techniques, high pressures and heat) with the aim of hydrolyzing (“breaking”) the milk proteins (see special milks).

The protein fragments thus obtained can have a more or less high molecular weight and, as such, are indicated in the diet of newborns with allergic forms of varying severity .

The milk of other animals, such as goat , sheep or buffalo milk, can not be consumed by those suffering from cow’s milk allergy, due to a phenomenon called cross-reactivity (these milks contain proteins with amino acid sequences similar to those of milk vaccine).

This characteristic, on the other hand, seems absent in donkey and mare ‘s milk , which however require further studies – both clinical and technological – before being used in the feeding of subjects allergic to cow’s milk.

An alternative to animal milks is represented by those based on more or less hydrolyzed vegetable proteins , such as soy milk , but enriched in deficient nutrients ( riboflavin , calcium ).

The latter, however, can in turn become an allergen (in 10-15% of cases, among those allergic to milk proteins). For this reason, some milk allergic infants are fed hydrolyzed rice protein products .

If the child suffers from cow’s milk allergy, it is sometimes necessary to remove the food and its derivatives even from the nurse ‘s diet .


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