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Wise et al.

Page 121

• Harm: Possible septal perforation, empty nose syndrome, nasal dryness, mucosal damage, epistaxis. • Cost: Office-associated vs operating room-associated procedural costs. • Benefits-Harm Assessment: Preponderance of benefit over harm. • Value Judgments: Properly selected patients can experience an improved nasal airway with judicious surgical intervention. • Policy Level: Option. • Intervention: Turbinate reduction with or without septoplasty may be considered in AR patients that have failed medical management, and have anatomic features which explain symptoms of nasal obstruction. In addition to allergen avoidance and numerous pharmacotherapy options, AIT is frequently considered in the management of AR. AIT involves scheduled administration of allergen extracts at effective doses with the goal of instituting a sustained immunologic change. AIT effectiveness is often measured through control of allergy symptoms and reduction in allergy medication use. The following section reviews the specifics of allergen extract units and standardization, allergen extract adjuvants and modifications, and subcutaneous and sublingual immunotherapy (SCIT, SLIT), as well as less traditional types of immunotherapy. IX.D.1. Allergen extract units, potency, and standardization— Historically, allergy testing began with pollen grains placed directly on the conjunctiva, 1569,1570 but as skin testing and SCIT became the diagnostic and immunotherapy treatment methods of choice, injectable allergen extracts were required. Inhaled allergenic particles are composed of a complex heterogeneous mixture of allergenic and non-allergenic proteins and macromolecules. Allergen extracts are created by collecting raw material from a particular species of plant, mold, or animal and then using a solution to extract proteins from the source. 1571 There are multiple sources of variance in allergen extracts. There is biologic variability in the raw material, and proteins can vary in antigenicity and composition; furthermore, the relative amounts of allergenic proteins may vary. 1572,1573 Impurities in the source materials, such as mold growing on pollen granules or bacteria on cat pelts, may also be immunogenic even if nonviable. Variation occurs in the collection and processing of the raw material. 1573 There is variability in the extraction process with different manufacturers using different techniques including filtration, extraction, sterilization, and preservation. 1571,1572,1574,1575 Only a very small fraction of the proteins extracted are allergenic. 1571 Given that the protein composition of allergen extracts is not known, producing and labeling allergen extracts that are safe and effective is challenging. Units and potency.: Allergen extracts are labeled with an assortment of units that provide an indirect indication of the allergen content of the extract. Most allergen extracts are labeled in units that do not convey information about biological composition or potency. There are

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IX.D. Allergen immunotherapy (AIT)

Int Forum Allergy Rhinol . Author manuscript; available in PMC 2020 June 10.