Placebo effect in otorhinolaryngology: A narrative review

Abstract

The word placebo has been used interchangeably to refer to a substance or procedure that is “inert” (“placebo”) and the effect that occurs as a consequence of its administration (“pla­cebo effect”). The placebo effect corresponds to a psychobiological phenomenon that has been explained from behaviorism (classical conditioning), from preconscious phenomena (expectations or “classical placebo effect”), from cognitivism (cognitive dissonance) and at the neurobiological level as well. Nevertheless, some open-label trials that verify the response to placebo challenge the expectation mechanism, giving rise to Bayesian analysis, which integrates sensations, experiences, predictions and context clues; therefore, biologically, the placebo effect is not inert. The placebo has a relevant place both in clinical practice and in biomedical research. We conducted a systematic search on placebo and otolaryngology in PubMed/Medline, SciELO and Cochrane Library databases. We included primary studies and systematic reviews. Regarding placebo interventions, the available literature points out significant improvements in nasal symptoms and quality of life in allergic rhinitis (seasonal and perennial) and a decrease in post-tonsillectomy pain. In Méniére’s disease, placebo interventions have demonstrated to be comparable to treatment-as-usual, including surgi- cal interventions. No open-label clinical trials were found in otolaryngology, as well as no evidence on other diseases in the area. Placebo interventions and their effects open a field of research and development in otolaryngology, challenging the current understanding of pathologies, their functioning, their treatment and the therapeutic relationship.