(RxWiki News) Researchers already knew that milk allergy was common among American children. But until recently, they weren’t sure how it compared to other food allergies.
A new study showed that milk allergy was the most common food allergy diagnosed in children in the United States. White children more often reported milk allergies than Asian or African-American children.
While less than half of milk-allergic children were tested by a doctor, it was the most commonly diagnosed food allergy.
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Christopher M. Warren, BA, of the Northwestern University Feinberg School of Medicine and the Ann and Robert H. Lurie Children’s Hospital of Chicago, and colleagues wanted to find out which children were developing milk allergies, how they were diagnosed and what their allergy experiences were.
To carry out the study, the researchers conducted a survey of 38,480 US households with children.
The survey asked about the children's age when they developed allergies, how they were diagnosed and what their allergic reactions were like throughout their lives.
Through this survey, the researchers found 3,218 children with allergies. After peanut, milk was the second most common allergy that parents reported. Of the total children with food allergies, 657 (19.9 percent) had milk allergies.
Not all of the children whose allergies were reported had been diagnosed by a doctor.
Of the children who reported milk allergies, 75 percent had been diagnosed by doctors. These children were doctor-diagnosed 1.7 times more often than children with other food allergies.
Equal numbers of male and female children had milk allergy. The most common age was between 6 to 10 years – 23.8 percent of those with milk allergies fell into this group.
The 11- to 15-year-olds were the least likely to have milk allergies. Only 15 percent of this age group reported allergy.
White children reported higher rates of milk allergy than other ethnicities. While 55.5 percent of the milk-allergic kids were white, only 19.8 percent were Hispanic, 16.6 percent were African-American and 4.7 percent were Asian.
Income difference did not seem to play a role in whether or not a child was likely to have a milk allergy.
On average, milk-allergic children had their first reaction when they were 2 years old. This was not significantly different than first reactions among children with different food allergies.
The children with milk allergies reported fewer severe reactions than children with other food allergies. While 31.3 percent of milk-allergic children reported severe reactions at one point in their lives, 47.2 percent of children with other food allergies had experienced severe reactions.
Children with milk allergies had four common mild symptoms. Almost half (48.7 percent) had experienced vomiting, 46 percent had had diarrhea, 35.5 percent suffered from hives and 35.2 percent developed eczema as part of their reactions.
The most common severe symptoms were wheezing (20.7 percent) and trouble breathing (16.9 percent).
Children with milk allergy reported developing a tolerance to milk earlier than children with other food allergies. While milk-allergic children could start exposure to milk at 4 years of age, those with other food allergies had to wait until they were 6 years old to begin tolerating the food they were allergic to.
Children with milk allergies were 2.1 times more likely to develop tolerance to milk than children with other food allergies.
Milk-allergic children were more likely to have a shellfish allergy as well, compared to all other food allergies. Shellfish was followed by fin fish and egg.
Among these children, 46.9 percent also suffered from seasonal hay fever, with 32.8 percent occurring in the spring.
“Milk allergy is highly prevalent among the US pediatric population, accounting for one-fifth of all food allergies,” wrote the authors.
The researchers noted that while milk allergies are diagnosed by doctors more often than other food allergies, there’s still reason to encourage more medical confirmation.
“In the absence of confirmatory diagnoses, children without a true milk allergy could potentially be subjected to unnecessary avoidance measures that may significantly affect a child’s quality of life,” wrote the authors.
“Efforts are needed to increase awareness about the importance of physician diagnoses and confirmatory testing of suspected milk allergy,” they wrote.
The study was published March 18 in the journal Annals of Allergy, Asthma & Immunology.
The research was funded by The Food Allergy Initiative in New York. The authors reported no potential conflicts of interest.