Rhinitis is an overall term for inflammatory conditions of the nasal lining. Symptoms comprise nasal obstruction, rhinorrhea, itch and sneeze. The majority of cases with chronic rhinitis can be attributed to allergic rhinitis on the basis of type I sensitization to aeroallergens. However a relevant proportion of patients reveals negative skin prick testing with no evidence of atopy though allergic disease would be suggestive. In these patients a broad spectrum of differential diagnosis has to be taken into account, that present differing pathophysiology and in consequence require specific treatment.