In addition to topical antimicrobial uses, aromatherapy has also been proposed for use in wound care [5,6] and to treat a variety of localized symptoms and illnesses such as alopecia, eczema, and pruritus.[7,8,9] Aromatherapy has also been studied via inhalation for airway reactivity.
Studies on aromatherapy have examined a variety of other conditions: sedation and arousal;[11,12] startle reflex and reaction time;[13,14]psychological states such as mood, anxiety, and general sense of well-being;[15,16,17,18,19,20,21,22,23,24,25,26,27,28,29] psychiatric disorders;neurologic impairment;chronic renal failure;agitation in patients with dementia;[31,32,33,34,35] smoking withdrawal symptoms;[36,37] motion sickness;postoperative nausea;[39,40] nausea and emesis in combination with fatigue, pain, and anxiety in patients in labor;[25,26,41] pain alone;[42,43,44,45] and pain in combination with other symptoms.[22,23,25,26]
Published articles have described the use of aromatherapy in specific hospital settings such as cancer wards, hospices, and other areas where patients are critically ill and require palliative care for pain, nausea, lymphedema,[46,47] generalized stress, anxiety, and depression. These observational studies provide examples of the clinical uses of aromatherapy (and other CAM modalities), though they are generally not evidence-based. Subjects have included hospitalized children with HIV, homebound patients with terminal disease, and hospitalized patients with leukemia. Aromatherapy has also been used to reduce malodor of necrotic ulcers in cancer patients.
Studies of aromatherapy use with mental health patients have also been conducted. Most of the resulting articles describe successful incorporation of aromatherapy into the treatment of these patients, though outcomes are clearly subjective.
Theories about the mechanism of action of aromatherapy and essential oils differ, depending on the community studying them. Proponents of aromatherapy often cite the connection between olfaction and the limbic system in the brain as the basis for the effects of aromatherapy on mood and emotions; less is said about proposed mechanisms for its effects on other parts of the body. Most of the aromatherapy literature, however, lacks in-depth neurophysiological studies on the nature of olfaction and its link to the limbic system, and it generally does not cite research that shows these links. Proponents of aromatherapy also believe that the effects of the treatments are based on the special nature of the essential oils used and that essential oils produce effects on the body that are greater than the sum of the individual chemical components of the scents.