Referral of the month: child's stubborn cough
Consultant paediatrician Dr Ashley Reece advises on a child with a persistent cough
Dear Dr Reece
Thank you for seeing this two-year-old boy with a history of recurrent cough. His mother says he has been snuffly since birth and that any respite from his cough seems shortlived. He has attended on numerous occasions and, over time, has had a variety of treatments, including antibiotics and asthma inhalers (including prophylaxis). None has shown any real benefit.
Looking through his records, he has, on a number of occasions, been described as having ‘crackles’ on his chest on auscultation. I couldn’t hear these today, although there were a lot of transmitted sounds. There has never been any suggestion of an inhaled foreign body, there is no relevant family history and neither parent smokes. He otherwise seems well – he is quite small but appears to be growing well and has a reasonable appetite.
His mother is convinced there is an underlying cause. Her online research has uncovered immune deficiency, cystic fibrosis or primary ciliary dyskinesia as possibilities, and she is keen on having these excluded.
I would be grateful for your thoughts. The presentation of recurrent URTIs and coughs in this age group is common in primary care so any guidance on when to consider an underlying cause would be most welcome.
Thank you for referring Jake. He has had recurrent cough over the past six months. His exercise tolerance is good. The cough can sound moist at times. He has no known allergies, is not on any medication and is up to date with his vaccines. The family has no pets but the maternal grandparents have a moulting dog, which does not make Jake’s cough worse. His mother has hay fever and his father has eczema and asthma.
On examination he was coryzal with an innocent-sounding heart murmur at the left sternal edge, grade 2/6, without radiation. Examination was otherwise normal and he did not cough during the consultation.
I note his mother’s concerns. There are no stigmata of chronic lung disease. Since 2008, babies have had an immunoreactive trypsin measured as a marker of pancreatic disease on the newborn screening blood spot test. The test has a high specificity. If we wanted to investigate further, a sweat test would be the next step. The reported crackles could be recurrent LRTI, but in the absence of multiple admissions with pneumonia further assessments for CF are unnecessary.
If there is a chronic chest condition or an inhaled foreign body, this would be apparent on chest X-ray, although he is a bit young to see changes in CF or other chronic lung disease such as primary ciliary dyskinesis. The latter is a genetic condition of poor ciliary function causing a similar clinical picture to CF. The clinical investigation is electron microscopy of nasal cilia. Rhinitis, blocked nose and productive cough are pointers to this condition. I suggest we assess for more common problems first.
We should consider environmental allergy (for example, house dust mite, cat or dog) in light of the first-degree relative with atopy. Skin-prick tests might indicate sensitisation. Response to a trial of antihistamine may support an allergic trigger. Non-IgE cow’s milk protein allergy can also cause respiratory symptoms. A dairy-free diet for two to four weeks would be the test to see if symptoms improve in this sort of allergy. Non-IgE cow’s milk allergy can also cause gastro-oesophageal reflux, or gastro-oesophageal reflux disease itself can cause laryngeal irritation, resulting in cough or hoarseness. In the absence of regurgitation or vomiting, this is less likely.
Likely postviral cause
IgA deficiency manifests with recurrent sino-pulmonary infections in the first few years of life. This is self-limiting and IgA levels improve over childhood. Prophylactic antibiotics may be required. In the absence of recurrent, more significant, infections in Jake, a serious immune deficiency is unlikely.
With regard to his lack of response to asthma treatment, it’s worth remembering that coughing after LRTI can persist for weeks or months, especially in pertussis or parapertussis. Asthma is not usually diagnosed until after the age of five years, and the presentation in younger children is a viral-associated LRTI, often with wheeze, called preschool wheeze. It might be worth a retrial of bronchodilators, using a spacer device.
Jake’s symptoms are likely postviral, causing bronchial hyper-reactivity and cough. I have reassured his mother it will improve in time. Children at this age can have 10 viral infections a year, which can seem to roll one to another with chronicity of symptoms. I have arranged a skin-prick test for environmental allergens and referred Jake for echocardiogram to assess anatomy. Atrial septal defect is linked with recurrent chest infections. If symptoms persist we will consider other differentials. I will review him in a month.
Dr Ashley Reece
- Assess for stigmata of chronic lung disease such as clubbing, wet cough, multiple antibiotic courses, recurrent admission to hospital with radiologically confirmed pneumonia, abnormal chest X-ray changes to consider an underlying lung pathology
- Cough post-LRTI, usually viral, may be helped by the treatments used for asthma, although the diagnosis of asthma is reserved for children aged over five years
- Consider infectious causes such as pertussis or parapertussis, which can cause cough for up to three months
- Consider other causes such as allergy, inhaled foreign body and immunodeficiency in recurrent lower respiratory symptoms and refer for specialist assessment if there are any co-existing issues, such as poor growth