Asthma
The Rapid Access Diagnostics for Asthma (RADicA) study will aim to determine the optimum diagnostic pathway for asthma and to determine the optimum series of investigations to predict “steroid-responsive airways disease” based on conventional tests of large airway function and novel tests of small airway function. The study will be a prospective cohort study. Participants with symptoms of asthma (i.e., cough, wheeze, chest tightness and/or breathlessness), not currently taking inhaled corticosteroid treatment will be recruited through primary and secondary care sources. Participants will undergo 4 core visits (2 before and 2 following standard asthma treatment), 1 telephone/text/email contact and up to 2 optional visits. At Core Visit 1, following written informed consent (and assent where applicable), the participant will be thoroughly evaluated (structured clinical history and examination) following a proforma. Participants in whom asthma is deemed low probability AND in whom an alternative diagnosis is suspected (e.g. pneumonia) would be withdrawn from the study and would be evaluated further in collaboration with their GP or if appropriate due to clinical urgency and/or severity direct referral to a general respiratory clinic would be arranged. All other participants will continue in the study. Those continuing will complete the following tests: 1. Skin prick test (if the patient is on antihistamines, this test will be deferred to a future visit and medication withheld as indicated) 2. Blood test(offered to all participants - can be completed at any baseline visit. However as these are not safety bloods, if declined the participant can still continue in the study) 3. Pregnancy test - if applicable 4. Nasopharyngeal swabs 5. FeNO 6. VOCs 7. IOS (pre-salbutamol) 8. PExA (pre-salbutamol) 9. MBW (pre-salbutamol) 10. Spirometry (pre-salbutamol) 11. Administration of inhaled salbutamol for bronchodilator reversibility testing 12. IOS (post-salbutamol) 13. Spirometry
1. Males and females >= 5 years and <70 years 2. Clinical suspicion of asthma from GP or referring health care professional 3. One or more symptom in keeping with asthma (i.e., cough, wheeze, chest tightness and breathlessness) 4. Capable of giving informed consent or where under 16 years attends with parent or legal guardian. 5. Participants must be able to communicate well in English
1. Pregnant women 2. Current ICS (used within previous 2 weeks) or oral steroid treatment (within the previous 4 weeks) 3. Former/Current smokers if > 10 pack year smoking history 4. Other relevant comorbidities (e.g., other lung disease; CF, COPD, ILD or bronchiectasis) 5. Recent antibiotic treatment within previous 2 weeks (these participants may be able to enter the study at a later date)