International Board of Certified Lactation Consultant (IBCLC) Practice Exam

What is the most common allergen affecting infants?

1. Wheat protein

2. Soy protein

3. Cow milk protein

4. Egg protein

The correct answer is: Cow milk protein

Cow milk protein is recognized as the most common allergen affecting infants. This is primarily due to the fact that cow's milk is often introduced into the diet of infants relatively early, particularly when transitioning to solid foods or when infants are formula-fed. Many infants' immune systems may react to proteins found in cow's milk, leading to conditions such as cow's milk protein allergy (CMPA). This allergy can manifest in various ways, including gastrointestinal symptoms, skin reactions, and respiratory issues. In the context of infant feeding, cow's milk is not recommended as a primary source of nutrition for infants under one year of age, as their digestive systems are not fully equipped to handle these proteins. This avoidance is crucial in reducing the risk of allergic reactions. All other options, while they can also be allergens, are less commonly identified as the primary allergens in infants than cow milk protein. For example, wheat and soy proteins might become problematic in toddlers and older children but tend to be introduced later in infancy. Similarly, egg protein can also trigger allergies, but cow's milk protein is statistically more prevalent in infancy, making it a critical focus for healthcare providers when assessing potential food allergies in this age group.