cow´s milk allergy

Cow´s milk allergy

Cow´s milk allergy 1024 576 Jaritzy Negrín González

Cow’s milk is the food that most frequently causes food allergies in children under 1 year of age.

Why is food allergy more common?

Because cow’s milk proteins are one of the first antigens (allergens) that the child comes into contact with in their diet.

How is cow’s milk composed?

Cow’s milk is composed of proteins that are classified into two groups: casein (80%) and whey proteins (20%). The main components of whey proteins are betalactoglobulins and alphalactalbumin.

These proteins are the allergens that trigger the production of antibodies.

Why is it called cow’s milk protein allergy?

These are clinical signs of an adverse reaction to cow’s milk with a proven immunological mechanism: reactions mediated by IgE antibodies or by another immunological mechanism (non-IgE). It is important to differentiate between both types because they present different pathophysiology, symptoms and evolution.

When do symptoms start?

It is variable, it can start during the period of exclusive breastfeeding but most cases begin when starting artificial breastfeeding after the period of breastfeeding. It begins in the vast majority of cases the first year of life with a maximum peak between 3-4 months of age. Exceptionally they can start after the second year of life.

What are the symptoms?

In 75-92% of children with cow’s milk protein allergy may have more than one symptom:

  1. Skin symptoms: this is the most common clinical condition characterized by erythema (redness), urticaria (wheal-like lesions) and angioedema (swelling). Initially it may appear in the perioral area and may or may not generalize to other parts of the body. Sometimes infants may have as their first and only clinical manifestation the refusal of cow’s milk bottle feedings or breastfeeding.
  2. Digestive symptoms: may be vomiting and diarrhea. In 30% of cases they are associated with other symptoms. Vomiting is a common clinical manifestation in IgE-mediated allergy.
  3. Respiratory symptoms: wheezing, cough, rhinoconjunctivitis are rare as an isolated symptom in the infant.
  4. Anaphylaxis: may be the debut in infants in 1% of cases. It is common in older children or adolescents with persistent cow’s milk allergy after accidental contact or transgression.

How is the allergy study carried out?

Allergy tests are indicated by making a personalized evaluation of each patient according to their clinical picture.

Initially in the consultation with your allergy specialist, a medical history is taken, detailed anamnesis of what happened is elaborated: type of symptoms, time of onset from ingestion of the food, if it is the first time it happens and it was referred spontaneously or with medication and of what type.

Subsequently, it is decided whether it is necessary to perform skin tests (prick tests) and blood tests to determine specific IgE for cow’s milk proteins.

According to the results, the performance of a controlled oral challenge test with cow’s milk will be assessed. This test consists of eating the food in progressive amounts under the supervision of an allergy specialist. Its goal is to confirm or rule out cow’s milk protein allergy. If the test result is positive, there is an allergy, it allows to know the threshold dose with which the patient presents symptoms when eating the food, avoiding unnecessary or very restrictive diets.

How is the evolution and prognosis of cow’s milk allergy?

Cow’s milk protein allergy tends to evolve into spontaneous remission in the short to medium term.

Clinical food tolerance is favorable in most infants and young children with IgE-mediated allergies. From 4 years of age, spontaneous tolerance is less likely. It is estimated that from 6-7 years of age cow’s milk protein allergy persists in 10%.

What is the treatment for cow’s milk allergy?

After the evaluating and diagnosing cow’s milk allergy, the elimination diet is the initial treatment of choice. This diet consists of the elimination of all cow’s milk proteins and foods that contain them. Cow’s milk can be replaced by hydrolyzed, elemental, soy or rice formulas.

For persistent cases that do not reach spontaneous tolerance, there is “Oral Immunotherapy” treatment, which consists of the progressive intake of food according to protocols and always supervised by an allergy specialist. Due to the risk involved, “oral immunotherapy” should be performed in the hospitall. The purpose of this treatment is to modify the allergic response by making the patient desensitized or tolerant to cow’s milk.

Remember to request the assessment of your allergy specialist if you suspect cow’s milk allergy, from ClinicAL we hope to have provided information about this allergy so frequent in the pediatric age.

Dra. Jaritzy Negrín González
Allergy Specialist