aDepartment of Medicine, Asthma, Allergy and Clinical Immunology Section, University of Verona, Verona, Italy

bRoyal Brompton & Harefield Hospitals, part of Guys and St Thomas NHS Foundation Trust

cDepartment of Inflammation and repair, Imperial College, London, UK

Correspondence to Dr Isabel J. Skypala, Departme nt of Allergy & Clinical Immunology, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK. Tel: +44 330 128 8992; fax: +44 330 128 7780; e-mail: [email protected]