The GP overview
The symptom GPs love to hate because it can appear so trivial. Reassurance and explanation are often all that is required, and this can build a bond with parents and children. Take parents seriously and sympathetically – nocturnal cough is a destroyer of sleep and family peace.
Differential diagnosis
Common
- URTI.
- LRTI.
- Post-nasal drip (for example, post URTI, allergic rhinitis).
- Asthma.
- Pertussis.
Occasional
- Inhaled foreign body.
- GORD.
- Psychogenic.
Rare
- TB.
- Cystic fibrosis.
- Earwax or foreign body in the ear canal.
- Immune deficiency.
- Interstitial lung disease.
- Congenital, e.g. trachea-oesophageal fistula.
Ready reckoner
| URTI | LRTI | PN drip | Asthma | Pertussis | |
| Child unwell | No | Possible | No | Possible | Possible |
| Chest signs | No | Yes | No | Possible | No |
| Spring/summer exacerbation | No | No | Possible | Possible | No |
| Marked nasal catarrh | Yes | No | Yes | Possible | No |
| Cough >three weeks | No | Possible | Possible | Yes | Yes |
Possible investigations
Likely
None.
Possible
FBC, ESR/CRP, chest X-ray, serial peak flow or spirometry.
Small print
- Pertussis serology, sweat test, secondary care investigations (for example, 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.
- Chest X-ray – may be helpful in LRTI, TB, inhaled foreign body, cystic fibrosis.
- Serial peak flow or spirometry – to help confirm a diagnosis of asthma.
- Pertussis serology – if a clinical suspicion of pertussis needs confirming.
- Sweat test – for cystic fibrosis.
- Other secondary care investigations – may be required after referral (for example, for interstitial lung disease or immune deficiency).
Top tips
- Think pertussis in any paroxysmal cough lasting more than three 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.
Red flags
- 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 should make you consider an inhaled foreign body.
- Beware the ‘poorly controlled asthmatic’ who isn’t thriving – this could be cystic fibrosis.
Dr Keith Hopcroft is a GP in Laindon, Essex.
Dr Vincent Forte is a GP in Gorleston, Norfolk.
The fifth edition of Symptom Sorter is available from Radcliffe Publishing for £34.99.
