Respiratory subtype of relapsing polychondritis frequently presents as difficult asthma: a descriptive study of respiratory involvement in relapsing polychondritis with 13 patients from a single UK centre.

Introduction Relapsing polychondritis is a rare multisystem vasculitis characterised by recurrent cartilage inflammation. Respiratory involvement, of which tracheobronchomalacia (TBM) is the commonest form, is difficult to treat and is linked to increased mortality. We describe 13 patients with respiratory involvement. Methods This is a retrospective study of all the patients with relapsing polychondritis at University Hospitals Coventry and Warwickshire NHS Trust (UHCW), a secondary care provider for ∼500 000. Only patients with respiratory involvement were included in this study. Results We identified 13 patients who fulfilled the inclusion criteria. Most patients were identified from the "difficult asthma" clinic. TBM was seen in 11 patients, whilst two patients had pleural effusions which resolved with immunosuppression and one patient had small airways disease. Computed tomography scans (inspiratory and expiratory) and bronchoscopy findings were useful in diagnosing TBM. Pulmonary function testing revealed significant expiratory flow abnormalities. All patients were treated with corticosteroids/disease-modifying anti-rheumatic drugs (DMARDs) and some were given cyclophosphamide or biological agents, although the response to cyclophosphamide (1 out of 4) or biologicals (2 out of 4) was modest in this cohort. Ambulatory continuous positive airway pressure ventilation was successful in four patients. Conclusions Relapsing polychondritis may be overlooked in "difficult asthma" clinics with patients having TBM (not asthma) and other features of relapsing polychondritis. Awareness of this condition is crucial to enable early diagnosis and interventions to reduce the risk of life-threatening airway collapse. A number of patients respond well to DMARDs and are able to minimise corticosteroid use