This Thursday it has been known that a 16-year-old girl has died in Manzanares (Ciudad Real) a 17-year-old girl due to an allergic reaction to a milk protein.
The cow’s milk allergy It is actually an allergy produced by some of its proteins, which is why it is known as CMA (cow’s milk protein allergy). It is the most frequent allergy in babies under one year of age (between 2 and 5%) and it usually appears when cow’s milk is introduced into the baby’s diet through adapted formulas, since it is very rare for a baby fed exclusively with breast milk suffers from it, even though cow’s milk proteins can be excreted through breast milk.
What are the causes?
As usually happens in allergies, this is due to a wrong and exaggerated reaction of the immune system before what it interprets as a threat, in this case the proteins beta-lactoglobulin and casein. To ‘fight’ them, the organism initiates the production of antibodies, among them Immunoglobulin E (IgE) and chemical substances such as histamine are secreted, which cause the symptoms. On other occasions, this allergy is produced by different mechanisms, and non-IgE-mediated allergy is referred to, which is more difficult to diagnose.
Usually this type of allergy it is usually genetic and disappear before the age of five, so it is very rare to see adults with CMA.
And the symptoms?
The symptoms can vary greatly depending on the sensitization of the patient and are usually appear within the first hour after drinking the milk. The most frequent are cutaneous (pruritus, oral erythema, hives, edema of the lips and eyelids…), followed by digestive (itching of the tongue, throat and palate, diarrhea, bleeding in the stool, abdominal colic, nausea, vomiting, regurgitation …), respiratory (rhinoconjunctivitis, asthma, wheezing) and in the most serious cases anaphylaxis. These symptoms appear in less than 60 minutes after taking or coming into contact with milk. Depending on the sensitivity of the patient, they can occur from the first sip or need a longer intake to manifest.
In case it is a non-IgE mediated allergy, the symptoms are usually only digestive and they can appear several hours or days after drinking the milk, which is why they are often confused with those of lactose intolerance.
How is it diagnosed?
When it is suspected that there may be an allergy to milk protein, skin tests and blood tests to detect milk-specific immunoglobulin E and its proteins, and controlled exposure to the allergen. These tests are for IgE-mediated allergy only. For those that are not mediated, the diagnosis is more complex, since the tests would be negative, and it takes more time, which can endanger patients, since cases of malnutrition may occur.
And how is it treated?
In the event of an acute allergic reaction, the treatment will be that corresponding to antihistamines, bronchodilators, adrenaline, etc Once the diagnosis is confirmed, the suspension of the consumption of milk and derivatives will be prescribed and replaced by special formulas, such as the extensively hydrolyzed lactose-free (split proteins and with less potential for allergy) or soy or rice-based formulas for people over 6 months. Nor should milk or dairy products from goats, sheep, etc. be taken. because the proteins of these milks are very similar to those of the cow, and can cause symptoms.
You have to keep a close eye on the processed foodsbecause in some cases, even traces of milk can trigger severe allergic reactions.
In the case of breastfed children, in some cases the mother must also discontinue consumption of these productssince the proteins of cow’s milk are excreted to the mother in small quantities.
In addition, it must be done periodic monitoring to determine the level of immunoglobulins and to measure the progressive tolerance of cow’s milk proteins; And in recent years, oral immunotherapy or oral desensitization treatment with milk has been addressed, that is, administering small, progressively larger amounts of food until reaching the maximum dose that can be tolerated.
CMA in children tends to disappear before the age of five, and only 15% of children with this type of allergy maintain it in adulthood. They are usually the most serious cases. And those who are most careful should be careful with the ‘hidden milk’ of some processed foods, we are snacks or pastries. after a variable period of time with an exclusion diet, so the specialist must periodically assess whether the child has outgrown the allergy to milk.
As regards prevention, there are no specific measures that have proven effective, but there are studies that suggest that exclusive and prolonged breastfeeding -18 months or more- could prevent milk allergy.
How is it different from lactose allergy?
Although there are people who often confuse them, the truth is that lactose intolerance and CMA they have little to do, as the Spanish Foundation reminds us of the Digestive System. These are the main differences:
- Lactose intolerance occurs to a sugar, and CMA, proteins.
- Allergy usually affects children and intolerance adults.
- Intolerance is a disorder of the digestive system and allergy of the immune system.
- The symptoms of intolerance are digestive (gas, nausea, bloating…) and those of allergy are much broader: skin, respiratory, digestive…