Diagnosing asthma in children under two

Lung health

It is common for infants to have recurrent episodes of cough and wheeze with colds and be completely well in between episodes. Usually, they will be diagnosed as having episodic viral wheezing. Despite what many parents are told, a small proportion will have genuine infantile asthma which is difficult - but not impossible - to diagnose in children under the age of two.

In this article, Dr Ian Balfour-Lynn from Royal Brompton Hospital shares his expertise.

Making a diagnosis

Many parents may report that their child wheezes. What they are really describing are the harsh sounds of upper airway secretions in the back of the child’s throat. A useful tip is to ask the parents to record the sounds on their mobile phones.

Key things to look for that suggest infantile asthma (rather than episodic viral wheezing) are:

  • Family history of atopy – asthma, hay fever or eczema in a parent or sibling.
  • Personal history of atopy – genuine atopic eczema rather than the occasional patch of dry skin, or a proven food allergy.
  • Pattern of wheeze – daily or night time symptoms or exercise/excitement induced symptoms.

Examination and investigations are usually found to be unhelpful as children under six years of age are unable to perform lung function testing.

If symptoms are marked or atypical, referral to a paediatrician with a respiratory interest is arranged. In some cases, further investigations may be performed to exclude less common diagnoses such as gastroesophageal reflux.


The single best thing most parents could do to help their symptomatic child is to stop smoking or remove animals that the child is allergic to, although this is rarely done.

Salbutamol (the blue inhaler)

These should only be used on an ‘as required’ basis rather than automatically taken three to four times a day. Syrup form has been found to be far less effective and not worth using, as the dose required orally to have an impact inevitably leads to side effects.

Montelukast (Singulair) 4 mg

Granules can be very useful to reduce viral airway inflammation and is not a steroid. They can be started at the beginning of a cold or chest symptoms and continued until the child is better rather than giving them a dose every day.

Inhaled steroids

A small minority of pre-school children will require regular prophylaxis. Inhaled corticosteroids are more likely to work in those with genuine infantile asthma.


Fortunately, the prognosis for those with genuine infantile asthma is generally very good and most will outgrow their symptoms.

However although most wheezy infants do not turn out to have persistent childhood asthma, most asthmatics do start wheezing when young. There is no way to predict what will happen for any individual child.


Dr Ian Balfour-Lynn

Consultant in paediatric respiratory medicine

Honorary senior lecturer at Imperial College London