Definition
Milk allergy, also called cow’s milk allergy or cow’s milk protein allergy, is an immediate type (type 1) food allergy. This means that the allergic reaction occurs within seconds to minutes and a delayed reaction is also possible after 4 to 6 hours. The incidence of milk allergy in infants and toddlers is about 2 to 3% of the population and is often seen in the first months of life after weaning.
The majority of children develop a tolerance in the first years of life, which means that they are then able to drink cow’s milk. In addition, adults can also develop a milk allergy. Women are more often affected than men and the allergy occurs between the ages of 20 and 50. Cow’s milk allergy is often confused with lactose intolerance, as both diseases have similar symptoms, but their causes are clearly different.
Milk allergy vs. lactose intolerance – What is the difference?
Milk allergy and lactose intolerance can cause similar symptoms. Abdominal pain, flatulence, diarrhoea and a feeling of fullness can occur in both diseases, which is why cow’s milk allergy can often be confused with lactose intolerance, i.e. an intolerance to milk sugar. The milk allergy has its cause in the immune system, which mistakenly judges milk proteins as foreign and dangerous.
In contrast, the cause of lactose intolerance lies in the intestines. There is no or too little lactase in the intestinal mucosa. Lactase is a digestive enzyme that breaks down the milk sugar from food.
The milk sugar lactose consists of glucose and galactose. The intestines can only absorb the sugar molecules if they have been split into the two small sugars by lactase. In case of lactose intolerance, the lactose reaches the large intestine unprocessed, where it is absorbed and fermented by intestinal bacteria.
This produces gases that cause flatulence and lactic acid. Lactic acid is osmotically active, which means that it causes an influx of water into the intestine. The liquid in the intestinal contents causes very liquid stool, which is why those affected often suffer from diarrhoea. Overall, milk allergy and lactose intolerance both often cause gastrointestinal complaints, but the causes and treatment options differ greatly.
All articles in this series:
