Defining Asthma in the Preschool-Aged Child

To the Editor.—I recently read Dr Robert Strunk’s article from the February 2002 supplement to Pediatrics.1Although he addresses urgent questions regarding the diagnosis of asthma in the preschooler, there are a few issues that I would like to question: Obviously a study with a larger sample would provide results that may be reproducible. However, the study should be designed in a way that confusing terms for the lay population are minimized or clearly explained, and the use of audiovisual aids should be considered.In Reply.—Dr Enriquez raises good points about the accuracy of parental reporting of wheezing and snoring. There have been several studies concerning the accuracy of parental reporting of respiratory sounds.1–3 Cane et al reported doctor and parent ratings of symptoms during 296 visits to the accident and emergency unit for children with wheeze or asthma at the Royal London Hospital.2 Parents and doctors were in agreement in only 45%. However, most disagreement was over reports of cough and upper airway noise by the parent when the doctor heard wheeze (this occurred in 39% of cases). There were few cases (14%) when parents complained of wheeze or asthma and the doctor found upper airway noise or nothing wrong. Thus, the results of this report seem to indicate that parents underreport, rather than overreport, wheeze. Cane and McKenzie3 used video clips of wheezing children as the gold standard. Parents were asked to name sounds the child was making, and then to localize the sound to the nose, throat, or chest. Correct labeling of wheeze occurred in 63% of cases. Only 7% of responses were wrong (instead indicating that the child was breathing normally or snoring); the remaining answers were vague or noncommital. Twenty percent of parents did not recognize wheeze even though their child had been diagnosed with wheeze in the past, again supporting the idea that parents underreport wheeze. Other sounds, snoring, stridor, or stertor were labeled correctly only 40% of the time. Stridor or snoring were mislabeled asthma or wheeze in 26% of the cases, supporting Dr Enriquez’s concern. Overall, these data would suggest that parents tend to underreport wheeze, rather than misidentify it. However, misidentification of upper airway sounds, particularly stridor as wheeze, does occur.The finding of snoring being associated with a diagnosis of asthma in the chart review was surprising. Perhaps, as suggested by Dr Enriquez, the association of snoring with asthma diagnosis is simply incorrect labeling. However, the findings of Cane and McKenzie3 would suggest that incorrect labeling would result in labeling of upper airway sounds as wheeze, rather than wheeze incorrectly identified as snoring. The association of snoring with asthma may simply be attributable to snoring representing more substantial upper airway inflammation and obstruction than present in children with “continuous rhinitis.” Asthma is an airway disease, frequently with significant involvement of both upper and lower airways. It may be that the extent of involvement of the upper airway in young children with asthma is intense enough to yield enough obstruction to produce the snoring noise. Continuous rhinitis was also seen in many of the children with asthma, but was not as specific as a history of snoring. Many children in the general population have runny noses, reducing the value of this indicator. What was surprising was the absence of snoring with diagnosis of sinusitis.What was interesting about the chart audit was the concurrence of both the words “wheeze” and “snore” with an eventual diagnosis of asthma. Although it is possible that some of the parents might have made mistakes in labeling wheeze and snore, it does appear that they are detecting something that is indicative of an eventual diagnosis of asthma.Exercise-induced symptoms did appear to be prevalent in young children with asthma. We assessed severity of asthma from the amount of medication eventually needed to control symptoms. The history of exercise symptoms was part of the initial history, and was not used as part of the severity determination. Thus, our conclusion that children with more severe disease were likely to have exercise symptoms came from independent assessment of these variables.For the issue of allergy, I would agree that environmental control is indicated in young children with persistent asthma, regardless of skin test results. However, if there is diagnostic confusion, doing skin tests may provide information that can help make a diagnosis of asthma or direct more attention to diagnostic possibilities other than asthma. Results of skin tests are not definitive, as other diseases causing either cough or wheeze, such as cystic fibrosis, can occur in children with allergies. Our survey results suggest that skin test results may be helpful in some cases.I was surprised that the retrospective chart review so clearly identified characteristics associated with asthma as opposed to those with sinus disease, for example. These results are meant to engender thought about an approach to a young child with respiratory complaints.