Cow's Milk Protein Allergy and Lactose Intolerance: Two Things Often Confused

Different mechanisms

Cow's milk allergy is an abnormal reaction of the immune system to the protein parts of milk. It may involve the skin, the digestive tract and the airways, and in severe cases it can cause a whole-body reaction. Lactose intolerance is caused by not enough lactase. The undigested lactose is fermented by bacteria in the gut, causing bloating, stomach rumbling, more gas and loose stools. It usually does not involve the immune system.

Differences in symptoms

• Cow's milk allergy: a rash, redness and swelling around the mouth, vomiting, diarrhoea, blood in the stool, or worse eczema can appear a short time after eating. In severe cases, breathing problems can occur
• Lactose intolerance: mainly bloating, gas and sour-smelling loose stools. Symptoms are related to how much is eaten, and a rash is rare
• When symptoms start: allergy often appears fairly quickly after contact, while lactose intolerance becomes clear as the amount eaten adds up

Why the difference matters

The way to manage them is completely different. Allergy needs strict avoidance of the allergenic protein, and a doctor should guide the choice of alternative feeding methods and nutrition plan. Lactose intolerance can often be improved by adjusting how much lactose is eaten, choosing low-lactose products, or drinking it with meals. Judging by "feeling unwell after drinking" alone can easily lead you the wrong way, and can delay monitoring of a child's nutrition and growth. If there is blood in the stool, no weight gain, or repeated vomiting, you should see a doctor promptly.

This article is for general information only and is not medical advice. Please follow your doctor's instructions.