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In Vivo Diagnostic Allergy Testing, Page 1 of 2
< Previous page Next page > /docserver/preview/fulltext/10.1128/9781555815905/9781555813642_Chap106-1.gif /docserver/preview/fulltext/10.1128/9781555815905/9781555813642_Chap106-2.gifAbstract:
Prick-puncture and intradermal skin testing are the most commonly used methods for the diagnosis of immediate hypersensitivity in allergic disease, while airway challenges may be used in the evaluation of rhinitis and asthma. This chapter describes the technique and utility of in vivo skin testing, intranasal allergen challenge, and specific and nonspecific lower airway challenge testing. These tools provide clinically useful information in the evaluation of the atopic patient. Allergen skin testing is considered to be the most convenient, least expensive, and most specific screening method in the diagnosis of allergic diseases. General principles that relate to in vivo examination are discussed in this chapter. Several methods have been developed to test the effect of antigen exposure on the nasal mucosal surface in allergic reactions. First, a specific antigen is identified by a combination of history consistent of allergic symptoms upon exposure to the antigen and positive skin testing, followed by intranasal challenge with that antigen. The two most commonly used methods of intranasal challenge include instillation of antigen into the nares either by spray pump or by nebulizer. The contraindications for methacholine and histamine challenges are essentially the same as for whole-lung antigen challenge. Persons exposed to oxidizing pollutants, smokers, and cystic fibrosis patients may also have increased reactivity based on methacholine and histamine challenges. Challenge procedures can be extremely useful in the investigation of allergy.