TV, radio and print advertisements that warn parents about the signs of rare but dangerous immune diseases in children may be misdirected, researchers say.
Their analysis, published today in Pediatrics, found that only a few of the 10 "warning signs" for so-called primary immunodeficiency diseases that are promoted by patient advocacy groups, such as the Jeffrey Modell Foundation, actually predict the disorders.
And information about those signs is probably more helpful in the hands of hospital specialists than given to the general public, the researchers say.
"It's really important that certain groups are targeted in terms of awareness in relation to these diseases," Dr. Peter Arkwright, one of the study's authors from Royal Manchester Children's Hospital in the U.K., told Reuters Health.
However, Arkwright said, "focusing on the general public may be using lots of money possibly in a direction where it might be better used for hospital specialists plus families" with a history of immune disorders.
The diseases targeted by the campaigns involve deficiencies in blood cells, such as the B- and T-cells that help fight off infection, or other critical elements of the immune system.
The disorders are rare - they only occur in about 1 in 10,000 people, Arkwright said - but they can cause death if not diagnosed early. For many immune disorders, symptoms start showing up in the first year or two of life.
People with immune deficiencies have a weakened defense system for fighting off germs and are very susceptible to infection. Treatment involves strengthening the immune system and preventing infection.
The Jeffrey Modell Foundation and other education and advocacy organizations tell parents to be on the lookout for kids who have trouble fighting off common infections or who get recurring infections that aren't easily cured with antibiotics.
The ten warning signs can be seen in detail on the foundation's website.
To see how effective those warning signs are at predicting immune disorders, Arkwright and his colleagues reviewed the medical records of more than 500 kids who had visited centers dedicated to immunodeficiency diseases in England.
About three-quarters of those kids were ultimately diagnosed with a primary immunodeficiency disorder.
Using the medical records, researchers were able to determine which of the warning signs each kid with or without a primary immunodeficiency disease had shown before doctors diagnosed or ruled out the diseases.
As it turned out, only three of the warning signs were more common in kids diagnosed with immune diseases. Those signs were a family history of immune disorders, the need for intravenous antibiotics to cure infections, and slow growth and weight gain.
Arkwright and his colleagues calculated that using only these three signs, 9 in 10 immune disorders could have been predicted.
Other warning signs on the list - such as recurrent ear or sinus infections or multiple cases of pneumonia - did not predict kids who were diagnosed with a primary immunodeficiency disease.
Almost all kids in the study had been referred to the immune centers from hospital doctors. That signaled to the authors that these specialists are the most important group to target with information about signs and symptoms of immune disorders.
"Patients are likely to only be symptomatic when they come across an infection, and at that point they're going to be seen usually by a hospital specialist," Arkwright explained.
He added that families who have had a child with an immune disorder should be aware that their other children are also at risk. In the study, a family history of primary immunodeficiency disease was 18 times more common in kids with the diseases than those without them.
Fred Modell, co-founder of the Jeffrey Modell Foundation - named after his son who died of a primary immunodeficiency disease - said that because the study did not look at every kind of immune disorder, it's still possible that certain disorders might have other specific warning signs.
There are over 150 different kinds of primary immunodeficiency diseases.
Modell said the 10 warning signs are meant as a screening tool, not to diagnose kids with an immune disorder. In that sense, he said, the list is quite effective.
"Any child with chronic, recurring, unexplained, particularly upper respiratory illnesses ... in which there isn't a clear diagnosis (who) has two or three or four of these warning signs, should be worked up" and tested for an immune disorder, Modell told Reuters Health.