Bacterial Infection Common With Children’s Chronic Wet Cough
January 9, 2012 — Purulent bronchitis is common among children with chronic wet cough, according to a retrospective study published online January 9, 2012, in Pediatrics.
In addition, 56% of the children in the study, all of whom had been referred to a pediatric pulmonary clinic because of an intractable wet cough, had bacterial infections of the lower airway. The investigators, led by Daniela Zgherea, MD, from the Department of Pediatrics, Maimonides Infant and Children’s Hospital, Brooklyn, New York, also found that tracheomalacia was identified on bronchoscopy far more frequently in the 0- to 3-year-old children in their study (30.3%) than in the general pediatric population.
The authors raise the need to better understand the etiology and best treatments for these lingering coughs (lasting 4 weeks or more).
“The diagnosis of ‘chronic bacterial bronchitis’ is not readily accepted in the pediatric population, however, as many physicians assume that is an ‘adult’ respiratory illness associated with tobacco smoking,” the authors write.
In the study, investigators reviewed the charts and bronchoscopy findings of 197 children referred by their primary care physician to a pediatric pulmonary clinic at Maimonides Infant and Children’s Hospital because of a persistent chronic wet cough. More than half of the study patients (55%) were aged 0 to 3 years, 36% were aged 3 to 7 years, and 9% were older than 7 years of age.
One third of the children in the youngest group had bronchoscopy-confirmed laryngomalacia or tracheomalacia. However, the frequency of laryngomalacia and tracheomalacia did not appear to be associated with purulent or nonpurulent bronchitis.
Bacterial cultures were positive in 91 children (46%). Of these, nontypable Haemophilus influenza accounted for nearly half (49%) of the positive cultures, Streptococcus pneumonia accounted for 20%, Moraxella catarrhalis accounted for 17%, and Staphylococcus aureus accounted for 12%.
Bacterial infections were more frequently associated with purulent bronchitis (84%) than with nonpurulent bronchitis (16%; P < .001). Regarding the 16% of children with purulent bronchitis who had negative cultures, the authors hypothesize these may be false-negatives, in part resulting from the timing of sputum collection relative to antibiotics use.
“The presence of a relatively large group of children with nonpurulent bronchitis and negative bacterial cultures among our study patients may point out the existing connection between chronic wet cough and asthma, which is also suggested by findings of [bronchoalveolar lavage] eosinophilia seen in some children in our study,” the authors write.
However, the study was unable to determine whether asthma contributed to the persistent cough. They recommend further prospective studies of the relationship between chronic wet cough, bacterial infections, and asthma in children.
The authors have disclosed no relevant financial relationships.