Cow’s milk protein allergy (CPVO) is the first food allergy to appear in children. It usually begins during the first months of life. How does it manifest itself? What are the treatments for APLV? Why shouldn’t it be confused with lactose intolerance? Answers from Dr Laure Couderc Kohen, allergist and pediatric pulmonary specialist.

When we speak of cow’s milk allergy, it is more precisely an allergy to the proteins contained in cow’s milk. People allergic to these proteins produce immunoglobulins E (IgE) as soon as they ingest foods containing cow’s milk proteins (milk, yoghurts, cheeses made from cow’s milk). IgE are proteins of the immune system that are potentially dangerous because they cause allergic symptoms of varying severity.

“Allergy to cow’s milk proteins is characterized by three main clinical pictures, that is to say three different types of symptoms: cutaneous and respiratory signs, digestive disorders and enterocolitis syndrome”, indicates the Dr Couderc Kohen. 

The first symptoms

The first clinical picture is manifested by:

• urticaria,
• respiratory symptoms
• edema,
• even anaphylactic shock in the most serious cases.

“In babies who are breastfed and allergic to cow’s milk protein, these symptoms often appear around weaning when parents start to bottle cow’s milk. We speak of immediate allergy because these signs appear very shortly after ingesting the milk, a few minutes to two hours after taking the bottle, ”explains the allergist. 

Secondary symptoms

The second clinical picture is characterized by digestive disorders such as:

• vomitings,
• gastroesophageal reflux,
• diarrhea.

In this case, we speak of delayed allergy because these symptoms do not appear immediately after ingestion of cow’s milk protein. 

Rarer symptoms

The third and rarer clinical picture is enterocolitis syndrome, which manifests as severe vomiting. Again, we talk about delayed allergy because vomiting occurs several hours after ingestion of the allergen. 

“These last two clinical pictures are less serious than the first which can lead to potentially fatal anaphylactic shock, but the enterocolitis picture still represents a significant risk of dehydration and rapid weight loss in toddlers”, points out the specialist. 

Note that digestive disorders and enterocolitis syndrome are allergic manifestations in which IgE does not intervene (IgE is negative in the blood test). On the other hand, the IgEs are positive when the APLV results in cutaneous and respiratory symptoms (first clinical picture).

If parents suspect an allergy to cow’s milk proteins in their child following the appearance of abnormal symptoms after ingestion of dairy products made from cow’s milk, a check-up should be carried out by an allergist doctor. 

“We carry out two examinations:

Allergy skin tests

They which consist of depositing a drop of cow’s milk on the skin and stinging through that drop to let the milk penetrate the skin.

Blood dosage

We also prescribe a blood test to confirm or not the presence of specific cow’s milk IgE in the immediate allergic forms ”, explains Dr Couderc Kohen. 

If a delayed allergic form is suspected (digestive disorders and enterocolitis syndrome), the allergist asks parents to exclude cow’s milk products from the child’s diet for 2 to 4 weeks. to see if the symptoms go away or not during this time.

Treatment of APLV is simple, it is based on a diet that excludes all foods made with cow’s milk protein. In allergic children, milk, yogurts and cheeses made from cow’s milk should be avoided. Parents should also avoid all other processed products that contain it. “For this, it is essential to check the labels showing the ingredients on the back of each product,” insists the allergist. 

In infants

In toddlers fed exclusively on milk (not breastfed), there are milk substitutes devoid of cow’s milk protein, based on hydrolyzed milk protein or amino acids, or based on vegetable proteins, sold in pharmacy. Always seek the advice of a pediatrician or allergist before choosing your cow’s milk substitute because babies have specific nutritional needs. “For example, do not replace your cow’s milk with sheep’s or goat’s milk because children who are allergic to cow’s milk can also be allergic to sheep’s or goat’s milk”, warns the allergist.

Eviction of the allergen

As you can see, APLV cannot be treated with medication. Only the elimination of the allergen in question makes it possible to eliminate the symptoms. As for children showing cutaneous and respiratory signs following the ingestion of cow’s milk proteins, they should always carry a first-aid kit containing antihistamine drugs as well as an adrenaline syringe to avoid respiratory problems and / or life-threatening anaphylactic shock.

Yes, usually APLV heals on its own over time. Few of the adults suffer from this type of allergy. “If it does not disappear, we proceed to an induction of oral tolerance, a therapeutic approach which consists in gradually introducing small quantities then larger quantities of cow’s milk in the diet until tolerance of the allergenic substance is obtained. .

This treatment, supervised by an allergist, can lead to a partial or complete cure and can last a few months or even a few years. It is on a case-by-case basis ”, explains Dr Couderc Kohen.

These are two different things.

Cow’s milk protein allergy

Cow’s milk protein allergy is an immune response against cow’s milk protein. The body of people with allergies reacts systematically to the presence of cow’s milk proteins and begins to produce IgE (except in digestive forms).

Lactose intolerance

Lactose intolerance is not an allergy. It results in troublesome but benign digestive disorders in people who cannot digest lactose, the sugar contained in milk. Indeed, these people do not have the enzyme lactase, capable of digesting lactose, which causes them bloating, stomach aches, diarrhea or even nausea.

“This is why we advise them to drink lactose-free milk or to consume dairy products which already contain the enzyme lactase, such as cheeses, for example”, concludes the allergist.