[Update on eosinophilic airway disorders]

Eosinophilic disorders of the airways affect the nose and paranasal sinuses, the bronchi and the lungs. Involvement of the nose includes the well known non allergic rhinitis with eosinophilia syndrome and new disorders characterized by co-participation of mast cells and neutrophils. Eosinophilic bronchitis must be distinguished from asthma, on the basis of some functional findings and a different cytokine profile. Eosinophilic pneumonia comprises acute and chronic forms, Churg-Strauss syndrome, hypereosinophilic syndrome, and eosinophilic granuloma, as well as secondary pneumonia such as Loeffler's syndrome.The treatment is mainly based on corticosteroids and the prognosis is variable, depending upon the development of acute respiratory failure (acute eosinophilic pneumonia, eosinophilic granuloma) or of vasculitis with multi-organ organ involvement in Churg-Strauss syndrome.