ABSTRACT
The most recent classification and differential diagnosis of rhinitis (rhinosinusitis), as described in previous chapters, are outlined in the allergic rhinitis (AR) and its impact on asthma document (Table 1) (1). Non-AR can be further classified into perennial or persistent non-AR, noninfectious non-AR, and six structurally related syndromes as outlined in Table 2. This chapter will concentrate on a few of the perennial causes of non-AR: the non-AR with eosinophilia syndrome (NARES) and the related entities of blood eosinophilia non-AR syndrome (BENARS) and metachromatic non-AR.
