The risk of asthma is increased by:
- A family history of allergic disorders such atopic eczema
- Smoking in pregnancy
- Sensitisation to allergens in the air
Why is Asthma often difficult to diagnose
Asthma is often far from a straightforward diagnosis to make. Why?
- International studies suggests that Asthma is often Overdiagnosis with around one third of cases being incorrectly labelled.
- Young kids, as every grandparent knows, are always getting upper and lower respiratory infections. A BMJ review of asthma diagnosis in kids in 2015 states “Typically, children may have more than 10 viral related colds a year, with symptoms lasting for more than two weeks. Non specific respiratory infections may also last for two weeks or more.”
- The symptoms of asthma may be very similar to the symptoms of a viral infection. To make matters more complicated, viral infections are a well known asthma trigger.
- Asthma is a condition that causes recurrent airway obstruction, and therefore requires an assessment of symptoms and signs over time.
- Under the age of 5, tests of lung function are usually not possible to perform.
What is Viral Wheeze?
Around half of kids under 5 will wheeze at some stage and the majority do not have asthma.
Infants & Toddlers often wheeze only with a viral infection and this is termed “Viral wheeze.”
Most viral wheeze does not turn into asthma, and the affected kids are well in-between episodes. Viral wheeze may be treated with a “reliever” inhaler usually used for asthma.
How can I tell that my child is likely to have Asthma?
The diagnosis of asthma is made in terms of probability of asthma – low, medium or high probability.
The greater the number of features, the greater the likelihood of asthma:
- Dry Cough (this feature on its own is unlikely to be asthma)
- Wheeze. Research shows that the term “wheeze” means different things to different people. The following Utube video demonstrates severe wheeze (this person went to the emergency department).
- Breathlessness – this is easier to establish than wheezing. Is there shortness of breath? Is there tightness in the chest?
- Symptoms worse at night and early morning
- Family history of asthma or allergies
- The child has eczema or hayfever
Asthma is also more likely if the symptoms seem to be triggered by laughing, exercise, damp air, cold air or exposure to pets. Recurrent symptoms without obvious features of a cold or viral infection are also suggestive.
Ultimately, the diagnosis of asthma is made by the doctor following observations made over a period of time.
Are any tests needed?
One of the most important tests is this: A clinician listening to the chest when there are symptoms. A wheeze is heard by the GP with a stethoscope in a very characteristic way and is usually unmistakable. The more episodes with proven wheeze, the greater the likelihood of asthma.
Peak flow meter helps show up obstruction before the child or adult is aware of symptoms. It’s a simple device you can buy directly from a pharmacy. The peak flow meter may be used from around the the age of 5, following the correct technique.
The idea is to write down the readings on a chart both morning and evening for around 2 weeks. There is a typical pattern of variability with asthma. The meter is also helpful in anticipating poor control in those with established asthma – the equivalent of a glucose meter for diabetes.
You may wish to consider allergy testing when there is a seasonal component to the symptoms or concomitant hayfever.
Preventers are divided into two main types:
Oral medication (Montelukast) that is licensed for use age 2 years or older, & being increasingly used first-line in kids for milder asthma
Inhaled steroids that have an important role in older kids & adults with moderate to severe asthma
What are the types of inhaler?
There is a huge range of asthma inhalers now available with a number of new devices and inhalants coming on board in 2014.
Each manufacturer produces their own range of relievers and preventers. Each range is characterised by the manufacturer’s device for delivering the inhaler – from the standard Ventolin meter dosed inhaler (press the canister) to the newest devices that deliver the inhalant automatically.
The colour code generally follows this
- Blue for reliever (eg. Ventolin, Bricanyl)
- Green for long-acting (eg. Serevent)
- Brown for Steroid inhalers (eg. Becotide, Flixotide)
- Purple for a combination of long-acting & Steroid (eg. Seretide, Symbicort)
The standard approach for inhalers is to change the Steroid inhaler to the Combined inhaler if the Steroid inhaler on its own is not controlling the Asthma.
How does my young child use an inhaler?
An inhaler cannot be used in a young child without a spacer device that sits between the lips and the inhaler. Children under 5 normally need a spacer (age 4-5 might be able to manage without it – but if in doubt use a spacer).
A child under 2 years will need to use the optional facemask with the spacer.
Spacers are sold directly by the pharmacies. There are a range of different spacer devices on the market. Popular ones that include the optional mask include Breathe A Tech, La Petite & Able.
The instructions for use of each spacer are simple. The key point is to form a seal between the spacer and your child’s mouth, and keep the seal during 4 to 5 normal breaths in and out (around 20 seconds).