Cow's Milk Protein Allergy
What is it?
It is an allergy reaction to cow’s milk protein. The reaction to the cow's milk protein can be immediate (IgE-mediated) or delayed (non-IgE-mediated). Immediate milk allergy occurs within two hours after ingestion of cow’s milk protein. The child may have a skin rash, lip swelling, tongue swelling, wheeze, airway compromise, difficulty in breathing, diarrhoea and vomiting. Non-IgE-mediated allergy occurs between 2 hours to 72 hours after ingestion of cow’s milk protein.
How common is it?
Cow's milk protein allergy is common. It occurs in 1% to 3% of infants.
What are the signs and symptoms?
Cow's milk protein allergy can present in many ways. Immediate allergy reactions includes lip swelling, tongue swelling, urticaria rash, abdominal pain, vomiting or diarrhoea which occurs within two hours after ingestion of cow's milk protein. Delayed reaction includes constipation, abdominal pain, eczema or nausea which occurs between 2 hours to 72 hours after taking cow’s milk.
How is it diagnosed?
Immediate allergy can be diagnosed by skin prick testing or blood test (IgE RAST test). A skin prick test can be performed by applying the food allergen drops onto patient's skin. A droplet is introduced into the skin via a lancet. A positive test is when the skin reaction with a wheal of 3mm or more in diameter. It is quick and easy. Often patients will have the result within 20 minutes. IgE RAST testing for common food allergens can also be done. The blood test result may take one week to become available.
Delayed reaction is sometimes difficult to diagnose. Negative skin prick testing does not rule out delayed food allergy or intolerance. If a patient has strong suspicion of food allergy, a period of exclusion diet followed by a food challenge is necessary. A child can develop milk allergy later in life, having had no symptoms during the infancy period.
What is the treatment?
The treatment of cow's milk protein allergy is avoidant of cow's milk protein. In infants with milk allergy, the mother will need to exclude dairy while breastfeeding, and this needs to be supplemented with calcium and vitamin D supplements such as Pregnacare. For infants who are bottlefeeding, they will need to be put on hypoallergenic formula milk such as extensively hydrolysed milk such as Nutramigen LGG, Similac Alimentum or SMA Althera. In severe milk allergy, an amino acid formula such as Neocate Syneo, Nutramigen Puramino or SMA Alfamino may be needed.
Important notes:
Milk allergy can cause constipation during the infancy period. In severe cases, it can cause rectal bleeding and diarrhoea.
Children who are on a dairy-free diet will need to take alternative plant based milk. Ensuring good calcium intake is vital for a growing child.
Children with delayed allergy or intolerance tend to react to the food when it is consumed in large amounts. Often they can present with intermittent vomiting, diarrhoea or abdominal pain when the consumption of cow's milk protein reaches the threshold they can cope. Therefore, children with unexplained intermittent vomiting mimicking cyclical vomiting may benefit from a trial of food exclusion such as dairy.
Book Appointment
Call 07961 767 854 or complete our enquiry form. We try to respond within 30 minutes between 7.00am and 7.00pm (London time).