Rethinking olfactory nerve assessment: A critical review of alcohol swabs versus essential oils

Mutungi, Esther Nyiva and Omogah, Fredrick Ochieng (2025) Rethinking olfactory nerve assessment: A critical review of alcohol swabs versus essential oils. Open Access Research Journal of Science and Technology, 13 (1). 039-043. ISSN 2782-9960

The olfactory nerve, essential for sensory perception, plays a vital role in detecting and interpreting odorants. Its assessment is traditionally conducted using ethanol swabs, which are widely regarded for their simplicity and accessibility. However, the use of alcohol in clinical olfactory testing presents notable limitations, including discomfort for patients and potential inaccuracies in results. Alcohol, as a nociceptive intranasal odorant, can stimulate the trigeminal nerve (cranial nerve V) rather than the olfactory nerve (cranial nerve I), thereby bypassing or confounding the intended sensory pathway. This unintended activation may compromise the reliability of the assessment and obscure true olfactory deficits. This review evaluates the limitations of alcohol in olfactory assessments and proposes essential oils as a viable alternative. Essential oils, such as peppermint, lavender, and eucalyptus, offer a diverse range of recognizable scents with favorable safety profiles. Unlike alcohol, these oils do not irritate the nasal mucosa and are less likely to trigger the trigeminal nerve, ensuring a more targeted and accurate evaluation of olfactory function. Furthermore, essential oils provide the added benefit of patient comfort, which may improve cooperation and compliance during testing. A shift toward the use of essential oils in olfactory testing could significantly enhance the accuracy and patient experience of clinical assessments. However, to establish essential oils as a standard in medical practice, further research is required. Studies should focus on standardizing testing protocols, optimizing concentrations, and evaluating cost-effectiveness to ensure their widespread and effective adoption.