Allergic rhinitis.

Abstract

Allergic rhinitis is a very frequent disease with a prevalence of 15-20%. Symptoms are most pronounced in young people while, for some unknown reason, the elderly become clinically hyposensitized. Pollen is the cause of seasonal allergic rhinitis, and house dust mite and animals are the main causes of perennial allergic rhinitis. Histamine is the main cause of sneezing and hypersecretion, while other mediators probably also play a role in nasal blockage. In polyposis, a local denervation is an important cause of vascular leakage, edema and polyp formation. Antihistamines have a positive effect on sneezing and hypersecretion, but not on blockage. As they have a quick onset of action they are useful in patients with mild and occasional symptoms. A nasal steroid is preferable in patients with persistent symptoms, since it is more effective on all nasal symptoms. Short-term use of a systemic steroid can be a valuable adjunct to topical treatment, especially in nasal polyposis, when there is a temporary failure of topical treatment in a blocked nose. A nasal vasoconstrictor can be added for short-term treatment, and an ipratropium spray can be beneficial in perennial non-allergic rhinitis, when watery secretion is the dominant symptom. Immunotherapy can be added in allergic rhinitis, when pharmacotherapy is insufficient. This chapter is based on the author's personal experience with allergic rhinitis, as a patient, a doctor and a researcher. Therefore, it is not a balanced review and the references will be highly selected as they largely consist of the author's own publications. As the text is mainly based on personal research, steroids are described in detail, while, with regard to immunotherapy, the reader is referred to another chapter. In addition to allergic rhinitis, nasal polyposis will be described. It was formerly believed to be an allergic disease, but we now know that it is not. However, with regard to histopathology and drug responsiveness this disease is very similar to allergic rhinitis.