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Wise et al.

Page 160

• Aggregate Grade of Evidence: C (Level 2b: 2 studies; Level 3b: 2 studies; Level 4: 4 studies; Level 5: 1 study; Table X.H).

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X.I. Laryngeal disease

AR has been implicated as a cause of laryngeal disease. However, further understanding of its precise role has been limited. While previous research has provided anecdotal evidence of a relationship between the 2, establishing a causal relationship between AR and laryngeal dysfunction had proven difficult due to a lack of safe and effective models for studying the larynx. 1995 Findings of laryngeal inflammation have largely been attributed to laryngopharyngeal reflux (LPR), but various etiologies may contribute to laryngeal dysfunction. Vocal dysfunction can have a significant psychosocial impact on patients, including those with AR. Several studies have reported higher Voice Handicap Index (VHI) scores in patients with AR compared to control subjects. 1996-1999 Dysphonia is particularly disturbing for professional voice users. Singers with self-perceived voice issues were 15% more likely to have AR than singers without vocal complaints. 2000 The likelihood of AR increased as the number of vocal symptoms increased. 2000 When comparing patients with AR and NAR to control patients, Turley et al. 2001 found that dysphonia was more prevalent in patients with asthma. A prior study had similar overall findings in patients with AR while controlling for asthma. 2002 Studies have reported the adverse effects of AR on voice-related QOL, and Turley et al. 2001 validated this by showing that patients who reported poor rhinitis-related QOL on questionnaires also had poor voice-related QOL and more severe chronic laryngeal symptoms. 1996,1998 The greater the degree of allergen load, the greater severity of vocal symptoms. 1999 Overall, patients with vocal dysfunction have a higher than anticipated incidence of AR and vice versa 1999,2001,2002 (Table X.I). Allergic laryngitis can be difficult to distinguish from other laryngeal inflammatory disorders, including LPR, due to the limitations of current diagnostic methods, which overall have poor specificity and interrater reliability. In a study of patients presenting with voice complaints, Randhawa et al. 2003 noted that two-thirds of patients were diagnosed with allergies whereas only one-third were diagnosed with LPR. However, allergy testing may be positive in up to 46% of the general population. 2004 Laryngeal findings in AR and LPR can be indistinguishable and include laryngeal edema, excessive mucus, vocal fold erythema, and arytenoid erythema. 1995,2005 A study by Eren et al. 2005 supported this diagnostic challenge in demonstrating no significant difference in the appearance of the larynx between allergy-positive and LPR-positive subjects; however, thick endolaryngeal mucus has been shown to be a predictor of allergy. Belafsky et al. 2006 and Mouadeb et al. 2007 examined the effects of Dermatophagoides on the laryngeal mucosa of guinea pigs and found an increase in eosinophilia compared to those exposed to saline, which provides some support for etiologies other than reflux contributing to laryngeal disease. In contrast, Krouse et al. 1998 were unable to demonstrate a difference in acoustic and speech aerodynamic testing or videostroboscopic evaluation between allergic patients compared to control subjects.

Despite anecdotal evidence implicating the role of allergic laryngitis in laryngeal dysfunction, there have been limited studies demonstrating a direct causal relationship

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