A Child Passed the Test to Resume Drinking Cow’s Milk
The child was monitored regularly by an allergist from infancy. At 35 months, he accidentally ate cake containing cow’s milk and developed hives and swollen eyelids, showing that tolerance had not yet developed.
His condition was followed through repeated measurements of specific IgE antibodies to cow’s milk and three of its protein components: alpha-lactalbumin, beta-lactoglobulin and casein. The tests were performed using the same laboratory method, FEIA, to allow results from different years to be compared.
Milk-specific IgE fell from 36 kU/L at six months of age to 28 kU/L at three years and 13 kU/L at five years. The values for the individual milk proteins declined in the same direction. The article notes that no single IgE threshold applies to every patient when deciding whether milk can be reintroduced.
A reduction of at least 50% in serum milk-specific IgE over 12 months is described as a recognised marker associated with the later development of tolerance. Accidental dietary exposures without symptoms may also provide evidence that a reaction is no longer occurring. In this case, the reductions affecting both whole milk and all the tested protein fractions led clinicians to proceed with an oral food challenge.
The challenge is used as the reference procedure for confirming whether a food allergy has resolved. The suspected food is administered in gradually increasing portions at set intervals until the quantity normally consumed by a child of that age is reached. If allergic symptoms appear, the procedure is stopped and the patient receives immediate care.
The test took place at Fleury’s Allergy and Immunology Centre, under the supervision of Lucila Camargo Lopes de Oliveira, a doctor who has conducted such challenges for at least 15 years. The boy consumed progressively larger amounts of unprocessed cow’s milk and developed no symptoms. The milk-free diet was then ended, and cow’s milk was authorised.
The article also states that specific IgE results do not have to become undetectable before an oral challenge is considered. Tolerance may appear while skin or blood allergy tests remain positive. Other common childhood food allergies include those involving eggs, soy, wheat, peanuts, tree nuts, fish and shellfish; allergies to milk, eggs, soy and wheat more often resolve during childhood, whereas reactions to nuts, peanuts, fish and shellfish are described as more persistent.
