We thank Giavina-Bianchi et al for their response to our letter. Treatment of patients with Churg–Strauss syndrome (CSS) remains a challenge owing to the heterogeneity of the underlying symptoms. We have followed our patients since early 2006 and have noticed an overall improvement in both pulmonary (obstructive airway disease) and systemic (ie, congestive) heart failure as a result of the addition of omalizumab. In particular, compared with the prior worsening, the clinical course of both patients remains improved since the addition of omalizumab. Both patients have also been on long-acting β₂ agonists and inhaled corticosteroids in standard doses throughout the time to control mild asthma symptoms (GINA I). In addition, they have required low dose prednisolone (5–10 mg) over the course of time to control blood eosinophilia, a hallmark of CSS exacerbation. We agree with Giavina-Bianchi et al that the long-term control of CSS requires immunosuppressant therapy and consider omalizumab as an effective add-on therapeutic agent. Because of the variability in the symptoms presented and the subspeciality of the referral centres who see these patients, a registry of patients with CSS is needed, based on clinical symptoms, regional background and therapeutic strategies. The underlying mechanisms as to how eosinophilia and cytokine signalling affects the course of the disease remains elusive and requires standardised treatment options and clarification of the molecular pathways to improve patient care.