The eyes are described by poets as being the windows to the soul. If that is so, then the nasal cavity is the window to the body. The nose is a highly accessible tool for observing the intricate details of the human immunological and vascular systems, especially as they relate to chronic rhinitis conditions. By examining the nasal mucosa and collecting secretions, the clinician or researcher can investigate normal physiological conditions and the allergic elements: the early phase, late phase, and chronic response. There are numerous methods developed to characterize and quantify nasal responses. The clinician can use some of these techniques whereas others are intended only for research purposes. This chapter will review three common procedures used in the evaluation of allergen-induced changes in
Each of these procedures is easily tolerated by the patient and can be performed in either the of ce or laboratory setting. Invaluable objective information is obtained regarding improvement and modi cation of the underlying in ammatory process. Each of these procedures will be reviewed, along with indications for the test, a discussion of the technique, and expected responses forpatients with and without nasal disease.
II. NASAL SMEAR A. Introduction Allergic rhinitis symptoms are an indirect response to mediators produced by activated in ammatory cells residing within the nasal mucosa and submucosa. In the allergic response, allergens bind to surface-bound IgE antibodies, resulting in mast cell activation. Cellular activation causes immediate release and subsequent production of in ammatory mediators such as histamine, platelet activating factor, leukotrienes, and prostaglandins. These mediators in turn cause an acute in ammatory reaction called the early allergic response. Both preformed and newly produced mediators promote the recruitment to the site of additional in-ammatory cells (eosinophils, neutrophils, basophils and lymphocytes). These cells continue the in ammatory process as the late phase response. The eosinophil is the primary in ammatory cell identi ed in allergic rhinitis, but lymphocytes, neutrophils, mast cells, and basophils are also present. Accurate identi cation of these cells assists the physician in correctly diagnosing the condition and selecting appropriate therapy. In the research setting, techniques for evaluating cellular components of nasal secretions give further insight into the pathogenesis and pathophysiology of allergic and nonallergic rhinitis. The nasal smear provides one means of identifying in ammatory cells in the nasal mucosa and the secretions. The Hansel stain, described by F. K. Hansel in 1953, is a rapid, easily performed technique used to identify the primary cellular components of nasal secretions (1). Over time, other diagnostic methods have been developed. This section will discuss nasal sampling techniques, staining techniques, cell evaluation, the clinical relevance of the diagnostic ndings, and the expected changes with therapy.