Key distinguishing features of the most common diagnoses
|Marked Nasal Catarrh||Yes||Possible||Yes||Possible||No|
|Cough >3 Weeks||No||Possible||Possible||Yes||Possible|
Possible:FBC, ESR/CRP, CXR, serial peak flow or spirometry.
Small Print:Pertussis serology, sweat test, secondary care investigations (e.g. for interstitial lung disease or immune deficiency).
- FBC, ESR/CRP: WCC raised in infection – marked lymphocytosis in pertussis; ESR/CRP elevated in any inflammatory process.
- CXR: May be helpful in LRTI, TB, inhaled foreign body, cystic fibrosis.
- Serial peak flow or spirometry: To help confirm a diagnosis of asthma (guidance recommends, in children over the age of 5, testing fractional exhaled nitric oxide in suspected asthma but this may not be practical, or available).
- Pertussis serology: If a clinical suspicion of pertussis needs confirming.
- Sweat test: For cystic fibrosis.
- Other secondary care investigations: May be required after referral (e.g. for interstitial lung disease or immune deficiency).
- Think pertussis in any paroxysmal cough lasting more than 3 weeks – it is much more common than most people, and many doctors, realise.
- Educate parents about the likely duration of URTI-related coughs and simple measures to take. Avoid prescribing, as this simply reinforces the tendency to attend the doctor for minor, self-limiting illness.
- In the asthmatic child, a cough may be a sign of poor control – check treatment, compliance and inhaler technique.
- Many parents panic that a cough might harm their child. An explanation that a cough is often simply a way of ‘keeping the lungs clear’ can defuse the situation.
- An aural foreign body is an unusual but remediable cause of childhood cough.
- Many parents wonder why their pre-school wheezy child has not been given a definitive diagnosis of asthma, particularly after treatment with bronchodilators. It is therefore worth broaching this by explaining the current way wheezy pre-school children are labelled, and why.
- Psychogenic cough typically does not occur at night.
- Parents tend to focus on the cough. In the acute situation, rather more important are symptoms and signs of respiratory distress – the NICE traffic light system for febrile children is useful in the acutely coughing febrile child and will help guide the need for admission.
- A dramatic and abrupt onset of coughing in a child without an URTI should make you consider an inhaled foreign body.
- Beware the ‘poorly controlled asthmatic’ who isn’t thriving – this could be cystic fibrosis.
- It can be difficult to distinguish between pneumonia and bronchiolitis in the unwell child. Children with pneumonia will tend to have a high fever and focal crepitations; children with bronchiolitis will be under 2 years old (most common in the first year of life), have a milder fever and more generalised sounds on auscultation. Whatever the diagnosis, if the child is unwell with respiratory distress, it needs admission.
- In a child with croup, admit if stridor or sternal/intercostal recession at rest, or if agitation or lethargy, pallor or cyanosis, or raised pulse or respiratory rate.