Hello, I'm Peter Barnes from Imperial College in London and I'm going to talk about
the similarities and differences between asthma
and COPD, and also talk about their overlap.
There are obvious clinical differences between asthma and COPD.
If you look at the symptoms of asthma,
they are characteristically variable with intermittent wheezing,
whereas COPD patients tend to have continual symptoms, and in particular
shortness of breath (SOB) on exertion.
Asthma attends to start in childhood,
the peak age of onset for asthma is three years,
but asthma can occur for the first time at any age,
even elderly people may develop asthma for
the first time. In COPD, because the disease takes many years to develop,
patients are usually aged over 45 and usually over 60.
The courses of these diseases differ;
asthma is a variable disease with periods of remission
which may be for several years (though some patients have progressive disease),
whereas COPD patients usually have progressive air-flow limitation.
Smoking is the commonest risk factor for developing COPD in developed countries
so most COPD patients are smokers, whereas asthmatics
smoke at around the same prevalence as the normal population.
Not surprisingly, the response to treatment differs between these diseases.
Characteristically, asthma is reversible,
so there's a good response to bronchodilators,
whereas COPD has largely fixed obstruction with a poor response to bronchodilators.
Asthma patients respond well to steroids,
so steroid responsive inflammation,
whereas COPD patients usually have a poor response to
steroids because they're inflammation is largely steroid resistant.
There are similarities in both asthma and COPD are common diseases,