AbstractRhinitis describes inflammation of the nasal mucosa. Clinically, it presents with symptoms of nasal discharge, itching, sneezing and nasal blockage or congestion. Rhinitis is a very common condition, affecting more than one in five of the UK population on an ongoing basis, and can be classified into allergic, non-allergic and infective types. Infective causes of rhinitis include bacteria and viruses, such as the common cold. They are not considered further here.