When can an infant be checked for allergies?

Any Age: If an infant is demonstrating signs/symptoms consistent with an allergic reaction, they can be tested at any age.

Varies: Birth with eczema makes an allergist think allergies are present since it is the first sign, typically, for an allergic child. I tend not to perform skin testing before age of 4 since it tortures the child and it rarely changes my treatment plan. I am not going to start allergy shots on a small baby. Blood tests are highly suspect.