Difficult asthma represents a significant unmet clinical need and burden on healthcare resources. We recently set up a difficult asthma clinic (DAC) in Plymouth and conducted an observational study of our experience to date.Methods
The DAC started in April 2010 evaluating patients using a systematic multidisciplinary approach. Patients were symptomatic at = Step 4 BTS guidelines and arose from a combination of cross referrals, inherited patients and asthmatics under regular chest clinic follow-up.Results
113 patients were evaluated within the DAC. 74 women. Mean age 48 yrs. 15 patients were felt either not to have asthma or asthma was not the primary diagnosis. Diagnoses included bronchiectasis (3), Goitre (1), obliterative bronchiolitis (1), tracheal involvement from ulcerative colitis (1), chronic pulmonary emboli (1), Churg-Strauss syndrome (1). 98 patients had difficult asthma. 14 patients had an occupational element, three with reactive airways dysfunction syndrome. 72 had comorbidities which included: vocal cord dysfunction/dysfunctional breathing (19), bronchiectasis (20), Class II Obesity (19), COPD/emphysema (9), GORD (31), immune deficiency (5), OSA (5), psychological (11), allergic bronchopulmonary aspergillosis (2). Medication at baseline: 46 patients were on long term oral corticosteroids (OCS) (mean 22 mg/d). Most patients were able to significantly reduce their OCS dose, mean reduction 53%. 12 were able to discontinue OCS entirely. Mean inhaled corticosteroid dose 2287 mcg/d (BDP equivalent). Subcutaneous terbutaline (3), cyclosporin (2), Anti-IgE therapy (1). Currently seven on anti-IgE therapy. 58 had severe refractory asthma by American Thoracic Society criteria. Mean IgE 531 kU/l, mean FeNO 40.5 ppb.15/58 had fungal sensitivity. Adherence: 1 of 12 patients tested was identified as non-adherent with undetectable prednisolone level and normal cortisol. Healthcare utilisation: 68 patients with 12 months follow-up data demonstrated a significant reduction in hospitalisations compared to the previous 12 months, 1.00 vs 0.53.Conclusion
This study highlights the importance of alternative diagnoses and comorbidities in the work up of difficult asthma. IgE and FeNO were higher than expected as was adherence to OCS compared to published studies. The implementation of a DAC has reduced hospital admissions, reduced OCS requirement and enhanced access to treatments such as Anti-IgE therapy.