Chronic cough in children: bronchoalveolar lavage findings

Abstract

Isolated chronic cough in childhood is a common complaint. Although the symptom cough is included in the definition of childhood asthma, there is debate as to whether the majority of these children have asthma. The authors studied children with isolated chronic cough looking for evidence of airway inflammation typical of asthma, with increased numbers of airway eosinophils as assessed from bronchoalveolar lavage (BAL).The investigations were carried out on 23 children (median age: 6.7 yrs; (range: 1.7±12.75 yrs), attending the Royal Belfast Hospital for Sick Children for elective surgery, who also had a chronic unexplained cough. Written informed consent was obtained from the parent(s) and a nonbronchoscopic BAL was performed. BAL samples were analysed for total and differential white cell counts and also for the inflammatory mediators, eosinophil cationic protein (ECP) and histamine. Results were compared with a group of normal nonatopic children and also a group of atopic asthmatic children, who had been recruited for other studies on airway inflammation.There was a small but statistically significant increase in BAL percentage eosinophils in the children with chronic cough compared with nonasthmatic controls (0.28% versus 0.10%, p=0.03). However, the children with cough had lower percentage eosinophils than the atopic asthmatic controls (0.28% versus 0.66%, p=0.01). Three out of 23 children with chronic cough had BAL eosinophils greater than the normal upper 95% reference interval in BAL. There was a small but statistically significant increase in percentage neutrophils in the children with cough compared with the nonasthmatic controls (5.85% versus 3.21%, p=0.03). Four out of the 23 children had BAL neutrophils greater than the normal upper 95% reference interval in BAL.The authors conclude that only a minority of children with chronic unexplained cough have asthmatic-type airway inflammation. It is speculated that the increased percentage neutrophils in bronchoalveolar lavage from children with cough could relate to underlying persistent airways infection.

Exhaled nitric oxide measurements with dynamic flow restriction in children aged 4-8 yrs

“…Moreover, symptom scores in the whole study population were low, and FENO values in children with and without symptoms were not significantly different. This suggests that, in this young age group, airway symptoms are less likely to be related to eosinophilic airway inflammation than in older subjects, thus confirming earlier observations [21]. Future studies using larger groups should establish reference values.…”

The diagnosis and management of chronic cough

“…BAL findings in a group of young children with chronic cough showed evidence of infectious mechanisms in a high percentage [81]. Many infections cause prolonged cough, including pertussis, tuberculosis, repeated viral infections and chronic ENT infections.…”

“…However, an "asthmatic"-type of inflammation, characterised by eosinophilic cell infiltration, appears rare in young children with chronic cough [81]. Comparison of cough frequencies between children with known asthma and healthy controls of school-age showed no differences between attacks, but more severe cough during bronchoconstriction [82].…”

Cough * 2: Chronic cough in children

“…12 Invasive studies of the cellular pathology of the airways of children with chronic cough are rare. Fitch et al 18 looked for the presence of asthmatic type airway inflammation in children undergoing elective surgery who had a history of coughing. After intubation for the surgical procedure a small volume of bronchoalveolar lavage (BAL) fluid was obtained.…”