Chronic Cough After Respiratory Illness
A recent study published (16th August 2017) in one of our most important medical journals highlights an issue that I believe we are only somewhat aware of and in which I wanted to provide some practical guidance.
THE STUDY
O’Grady KF, Drescher BJ, Goyal V, et al. Chronic cough postacute respiratory illness in children: a cohort study. Archives of Disease in Childhood Published Online First: 16 August 2017. doi: 10.1136/archdischild-2017-312848
The Findings
Children who continue to cough 4 weeks after an acute respiratory illness often have underlying respiratory pathology i.e. a persisting or alternative respiratory illness. About a third (30.8%) of children evaluated for chronic cough (CC) after acute respiratory illness (ARI) were diagnosed with a new and serious lung disease, and 47.0% were found to have protracted bacterial bronchitis.
The authors concluded “CC is often the sole presenting symptom of an underlying chronic RI, and in some conditions, if left untreated, it may result in irreversible lung damage and chronic lung disease. Furthermore, CC impairs quality of life…and stresses parents, both of which normalise when the cough resolves,”.
It was a large study, whcih included 839 children younger than 15 years (median age, 2.3 years – that’s 50% of children in the study with an age of 2.3 years or less) who presented to a large pediatric emergency department (ED) with ARI. The researchers excluded children with chronic lung disease (except asthma) and/or immunosuppression, as well as those who had used immune-modulating drugs (except oral or inhaled steroids) in the 30 days before being seen in the ED. Most (n = 627; 74.8%) of the children had been coughing for less than 1 week at enrollment.
One fifth (171; 20.4%; 95% confidence interval [CI], 17.7% – 23.1%) of the children continued to cough at day 28.
Among those with chronic cough, 117 were evaluated by a specialist in paediatric lung function and injury. Pulmonology evaluation revealed a new chronic underlying lung disease in 36 (30.8%) children.
Protracted bacterial bronchitis was the most common diagnosis made during pulmonologist evaluation (n = 55/117; 47.0%), and 37/117 (31.6%) of the children received more than one diagnosis. Fourteen children were diagnosed with recurrent upper RIs, and four were diagnosed with pneumonia. Four children were diagnosed with aspiration disorders, three of whom were previously undiagnosed.
Making Sense and Sensible Advice
The study shows that a cough persisting at 28 days after a respiratory illness can be symptomatic of a further problem i.e. not just a lingering version of the existing problem. In medical terms, a symptom that suggests 30.8% of those presenting with it have some sort of more serious underlying respiratory problem is fairly profound. We are often working off much weaker signals.
I think one of the issues parents face is that we do not think of 28 days at the time our children first get something and then, by the time we start thinking “this has been around a while” we have really no idea when it actually started or happened. In the era of iPhones etc., maybe we should get into the habit of noting the start date and perhaps end date of the main symptoms of respiratory problems in our children. We can then check back when we become aware that our child is still coughing some time later. It is certainly helpful to us paediatricians to have firmer dates when we start to consider our investigations and evaluations.
I think the key advice that arises out of this is that we need to be much more aware of a persisting cough and seek professional as soon as it appears to be approaching this time point.
Your child may need a pulmonary evaluation. As a neonatologist (as well paediatrician), this is something I monitor for, follow up on and do frequently, as our preterm infants already have a higher chance of pulmonary problems resulting from their earlier challenges.
However, this is an evaluation that many paediatricians can undertake and, if not themselves, know who to refer to. The advice is, if your child has a persisting cough at 28 days after some sort of respiratory-related illness – they need to see their paediatrician.
Have concerns?
If you want specific advice or are concerned about your child’s persisting cough (or any other problem), please get in touch.