Facial 'pillow' dermatitis due to lavender oil allergy

A review of the bioactive components and pharmacological properties of Lavandula species

Lavandula species is a flowering plant that is common in Europe and across the Mediterranean. Lavender has many health benefits for humans. In addition to its use in herbal medicine, it is widely used in the fields of cosmetics, perfumes, foods, and aromatherapy. Google Scholar, PubMed, Scopus, and Web of Science were used to search for relevant material on the phytochemical ingredients, the pharmacologic effects of the ingredients, and the mechanism of action of the Lavandula species identified. These materials were reviewed in order to have access to important updates about the Lavandula species. Lavender as referred to in English contains essential oils, anthocyanins, phytosterols, sugars, minerals, coumaric acid, glycolic acid, valeric acid, ursolic acid, herniarins, coumarins, and tannins. It has been used to treat colic and chest ailments, worrisome headaches, and biliousness, and in cleaning wounds. It has antifungal, antibacterial, neurologic, antimicrobial, anti-parasitic, anti-diabetic, and analgesic effects among others. Lavandula species has prospects for various biological applications, especially with its dermatological application. Advances in drug development would enable characterization of various bioactive constituents; thus, its development and application can have a more positive impact on humanity. Here, we highlighted updated information on the history, distribution, traditional uses, phytochemical components, pharmacology, and various biological activities of Lavandula species.

[Retrospective surveys on intoxications with essential oils]

OBJECTIVES

Non-conventional medicines are not devoid of toxicity and it is relevant to establish an inventory of the general public's knowledge of essential oils. The objective is to identify the profile of the victims of a poisoning, the ways of administration and the symptoms as well as the incriminated essential oils.

METHODS

Two surveys, for the general public and health professional, were distributed (January-March 2019). In addition, data from the Angers poison control center for the period 2017-2018 were analyzed and compared with the data from our study.

RESULTS

Our surveys gathered 623 and 59 answers. The data of the poison control center of Angers counted 741 intoxications. The precautions for use and contra-indications of essential oils are not well known since 5% of the respondents identified them correctly. Our data show that using a mixture increases the risk of intoxication (P<0.02). The most cited essential oils in case of intoxication are Eucalyptus, Tea tree and Lavender. The symptoms mainly concern a cutaneous application (75%) and remain of short duration and without gravity. Concerning the intoxications referenced to the poison control center in Angers, the same essential oils are involved, the oral route is mostly used (70%) and the symptoms listed for 74% of intoxications concern oropharyngeal, ocular, abdominal and skin pain.

CONCLUSION

The delivery of essential oils is not harmless and the data obtained both through our surveys and the processing of data from the poison control center of Angers show that they must be used with caution.

Effect of Lavender (Lavandula angustifolia) Essential Oil on Acute Inflammatory Response

Lavandula angustifolia is a plant of Lamiaceae family, with many therapeutic properties and biological activities, such as anticonvulsant, anxiolytic, antioxidant, anti-inflammatory, and antimicrobial activities. The aim of this study was to evaluate the effect of Lavandula angustifolia Mill. essential oil (LEO) on acute inflammatory response. LEO was analyzed using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR) methods and showed predominance of 1,8-cineole (39.83%), borneol (22.63%), and camphor (22.12%). LEO at concentrations of 0.5, 1, 3, and 10 μg/ml did not present in vitro cytotoxicity. Additionally, LEO did not stimulate the leukocyte chemotaxis in vitro. The LEO topical application at concentrations of 0.25, 0.5, and 1 mg/ear reduced edema formation, myeloperoxidase (MPO) activity, and nitric oxide (NO) production in croton oil-induced ear edema model. In carrageenan-induced paw edema model, LEO treatment at doses of 75, 100, and 250 mg/kg reduced edema formation, MPO activity, and NO production. In dextran-induced paw edema model, LEO at doses of 75 and 100 mg/kg reduced paw edema and MPO activity. In conclusion, LEO presented anti-inflammatory activity, and the mechanism proposed of LEO seems to be, at least in part, involving the participation of prostanoids, NO, proinflammatory cytokines, and histamine.

Is lavender an anxiolytic drug? A systematic review of randomised clinical trials

BACKGROUND

Lavender (Lavandula angustifolia) is often recommended for stress/anxiety relief and believed to possess anxiolytic effects.

AIM

To critically evaluate the efficacy/effectiveness of lavender for the reduction of stress/anxiety.

METHODS

Seven electronic databases were searched to identify all relevant studies. All methods of lavender administration were included. Data extraction and the assessment of the methodological quality of all included trials were conducted by two independent reviewers.

RESULTS

Fifteen RCTs met the inclusion criteria. Two trials scored 4 points on the 5-point Jadad scale, the remaining 13 scored two or less. Results from seven trials appeared to favour lavender over controls for at least one relevant outcome.

CONCLUSION

Methodological issues limit the extent to which any conclusions can be drawn regarding the efficacy/effectiveness of lavender. The best evidence suggests that oral lavender supplements may have some therapeutic effects. However, further independent replications are needed before firm conclusions can be drawn.

Silexan, an orally administered Lavandula oil preparation, is effective in the treatment of 'subsyndromal' anxiety disorder: a randomized, double-blind, placebo controlled trial

This study was performed to investigate the anxiolytic efficacy of silexan, a new oral lavender oil capsule preparation, in comparison to placebo in primary care. In 27 general and psychiatric practices 221 adults suffering from anxiety disorder not otherwise specified (Diagnostic and Statistical Manual of Mental disorders-IV 300.00 or International Statistical Classification of Diseases and Related Health Problems, Tenth revision F41.9) were randomized to 80 mg/day of a defined, orally administered preparation from Lavandula species or placebo for 10 weeks with visits every 2 weeks. A Hamilton Anxiety Scale (HAMA) total score >or=18 and a total score >5 for the Pittsburgh Sleep Quality Index (PSQI) were required. The primary outcome measures were HAMA and PSQI total score decrease between baseline and week 10. Secondary efficacy measures included the Clinical Global Impressions scale, the Zung Self-rating Anxiety Scale, and the SF-36 Health Survey Questionnaire. Patients treated with silexan showed a total score decrease by 16.0+/-8.3 points (mean+/-SD, 59.3%) for the HAMA and by 5.5+/-4.4 points (44.7%) for the PSQI compared to 9.5+/-9.1 (35.4%) and 3.8+/-4.1 points (30.9%) in the placebo group (P<0.01 one-sided, intention to treat). Silexan was superior to placebo regarding the percentage of responders (76.9 vs. 49.1%, P<0.001) and remitters (60.6 vs. 42.6%, P=0.009). Lavandula oil preparation had a significant beneficial influence on quality and duration of sleep and improved general mental and physical health without causing any unwanted sedative or other drug specific effects. Lavandula oil preparation silexan is both efficacious and safe for the relief of anxiety disorder not otherwise specified. It has a clinically meaningful anxiolytic effect and alleviates anxiety related disturbed sleep.

Lavender oil lacks natural protection against autoxidation, forming strong contact allergens on air exposure

BACKGROUND

Lavender oil is an essential oil frequently used as a fragrance ingredient and in traditional herbal medicine. We have previously studied the effect of air oxidation on the skin sensitizing potency of the monoterpenes linalyl acetate, linalool and beta-caryophyllene, the main constituents of lavender oil.

OBJECTIVE

The aim of this study was to investigate if the autoxidation observed for the single synthetic terpenes, resulting in strong contact allergens, will take place also in lavender oil.

METHODS

Lavender oil was exposed to air and the autoxidation was followed by chemical analysis. The sensitizing potency before and after air exposure was investigated in mice using the local lymph node assay. Patients with patch test reactions to oxidized linalool were tested to investigate if air-exposed lavender oil could elicit dermatitis in these individuals.

RESULTS

The terpenes oxidized in air-exposed lavender oil at the same rates as the pure compounds exposed to air, and the same oxidation products were identified. The sensitizing potency of lavender oil increased accordingly on air exposure. Patch testing showed positive reactions to air-exposed lavender oil and also to oxidized linalyl acetate in patients with contact allergy to oxidized linalool.

CONCLUSION

This study shows that lavender oil lacks natural protection against autoxidation, and that air-exposed lavender oil can be an important source of exposure to allergenic hydroperoxides.

Complementary and alternative interventions in asthma, allergy, and immunology

OBJECTIVE

To review which herbs are most commonly used as complementary and alternative medicine (CAM) for treatment of asthma, allergy, and immunologic conditions.

DATA SOURCES

A review of the literature was performed using the PubMed and OVID databases searching the keywords asthma, allergy, and CAM to identify studies published between 1980 and 2003 that focused on Echinacea (Echinacea augustifolia, Echinacea pallida, and Echinacea purpurea); garlic (Allium); angelica; chamomile; ephedra; gingko; grape seed extract; licorice root (Glycyrrhiza); St. John's wort (Hypericum); kava kava (Piper); peppermint oil and leaf (Mentha); stinging nettle (Urtica); and ginseng (Panax) published in the English and German literature.

STUDY SELECTION

Studies included in vitro and in vivo clinical trials and case reports selected according to the expert opinion of the author.

RESULTS

Echinacea is one of the most common herbs used to treat symptoms of the "common cold" or upper respiratory tract allergies. Although no common drug interactions have been reported, there is a risk of hepatotoxicity, exacerbation of allergies and asthma, and anaphylactic reactions. Garlic is primarily used for cardiovascular health and relief of cough, colds, and rhinitis. Adverse effects commonly include gastrointestinal disturbances, change in body odor through the sweat and breath, and rarely allergic reactions or hypoglycemia. Other CAM agents, including angelica, German chamomile flower, ephedra, gingko, grape seed extract, licorice root, St. John's wort, kava kava rhizome, peppermint, stinging nettle, and ginseng, are also associated with significant adverse effects.

CONCLUSION

The specialty of allergy and immunology has seen the second largest increase in the popularity of CAM (second only to practitioners who treat lower back pain). Almost all of the CAM interventions have displayed adverse effects, usually in the form of a hypersensitivity reaction. Allergists and clinical immunologists need to become more knowledgeable about CAM so that they can inform patients about the use and possible abuse of these modalities.

Biological activities of lavender essential oil

Essential oils distilled from members of the genus Lavandula have been used both cosmetically and therapeutically for centuries with the most commonly used species being L. angustifolia, L. latifolia, L. stoechas and L. x intermedia. Although there is considerable anecdotal information about the biological activity of these oils much of this has not been substantiated by scientific or clinical evidence. Among the claims made for lavender oil are that is it antibacterial, antifungal, carminative (smooth muscle relaxing), sedative, antidepressive and effective for burns and insect bites. In this review we detail the current state of knowledge about the effect of lavender oils on psychological and physiological parameters and its use as an antimicrobial agent. Although the data are still inconclusive and often controversial, there does seem to be both scientific and clinical data that support the traditional uses of lavender. However, methodological and oil identification problems have severely hampered the evaluation of the therapeutic significance of much of the research on Lavandula spp. These issues need to be resolved before we have a true picture of the biological activities of lavender essential oil.