The role of caffeine in otorhinolaryngology: guilty as charged?

Caffeine is implicated as causing or aggravating numerous otorhinolaryngological conditions, including tinnitus, Ménière's disease, laryngopharyngeal reflux, globus pharyngeus and dysphonia. We address caffeine's effects in such conditions and to determine whether such implications are founded. The defined search limits of data sources included human trials and either randomised control trials, meta-analyses, editorials, letters, clinical trials, case reports, comments or journal articles over the last 40 years. MEDLINE, EMBASE and CINAHL databases were searched using 'otorhinolaryngological diseases' and 'caffeine' as a duplicate filter. PubMed databases were searched using 'caffeine' in combination with 'tinnitus', 'Ménière's', 'vertigo', 'motion sickness', 'imbalance', 'vestibular migraine', 'voice', 'vocal hygiene', 'reflux', 'ear', 'nose', 'throat' and 'head neck cancer', respectively. Searches were not limited to the English language. MEDLINE, EMBASE and CINAHL database searches identified 417 papers. Of these, 200 abstracts were chosen for further scrutiny, following which 30 full manuscripts were chosen for full review. The PubMed database search identified 275 abstracts of which 33 were reviewed. Of the total 692 studies searched, 63 studies were reviewed and 36 were finally used. At present, there is little evidence in the literature to support the notion that caffeine causes or aggravates otorhinolaryngological conditions. In tinnitus, its withdrawal may actually worsen symptoms whereas in motion sickness, there is some clinical evidence for its benefit. More research is needed into the role caffeine plays in otorhinolaryngological conditions to allow clinicians to give informed advice to their patients.