Cross Sectional Study to Evaluate and Associate Clinical and Laboratory Features of People With Allergic and Non-allergic Asthma

In the past, doctors separated people with asthma into two groups, those with "allergic asthma" (about 2/3rds of people) and those with "non-allergic asthma". These labels are not much used now as the treatments for all people with asthma don't depend on this classification. However, new treatments for asthma may become available and the classification may again become important. It could be useful for clinicians to know how to identify which patients are likely to benefit from particular treatments.

Additionally, some new blood tests are becoming available and some of these might help to categorise the type of asthma people have. What the study hopes to do is to identify patient features which make a diagnosis of "allergic asthma" more likely and to see which new blood tests are most likely to be helpful in confirming this diagnosis.