AviNavi, welcome, I don't doubt you had a wonderful experience, but
(see forum rules) it is irresponsible and potentially dangerous to recommend anybody applies undiluted essential oil to the skin, particularly on the face, where it could easily migrate to mucosa (nose, mouth, eyes) as well as being at risk of developing further phototoxic effects (such as occurs with many citrus oils).
I attach the relevant table from "Essential Oil Safety, 2nd Ed. 2014" by Robert Tisserand et al*
*[Do not take any advice on essential oils from anybody who is not intimately familiar with this reference text]
You will see that ylang ylang has an established dermally-safe maximum concentration of 0.8% so recommending its use at 100% (a factor of 125x) is indefensible. A key aspect of sensitisation is that it is usually progressive: low or no effects on first exposure, but rapidly increasing effects with subsequent exposures at the same site.
Many practitioners (myself included) have suffered severe, long-lasting adverse skin reactions as a consequence of our activities, and it should not be overlooked that ALL essential oils, even the 'calming, soothing' ones are considered FIRE medicines in traditional systems (eg. ayurveda) due to their method of production and potency.
Use a few drops, in a safe vaporiser or diffuser, out of reach. Don't take risks, especially when blasting off into a period of incapacity, with a high chance of eye/face rubbing. The established treatments for atopic dermatitis are generally ineffective and unpleasant, and I experienced a full year of debilitating, severe symptoms, which pushed me to the brink of suicide, until I found an effective TCM practitioner.
Chan attached the following image(s):
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Skin Sensitization Tisserand.jpg
(2,805kb) downloaded 130 time(s).“I sometimes marvel at how far I’ve come - blissful, even, in the knowledge that I am slowly becoming a well-evolved human being - only to have the illusion shattered by an episode of bad behaviour that contradicts the new and reinforces the old. At these junctures of self-reflection, I ask the question: “are all my years of hard work unraveling before my eyes, or am I just having an episode?” For the sake of personal growth and the pursuit of equanimity, I choose the latter and accept that, on this journey of evolution, I may not encounter just one bad day, but a group of many.”
― B.G. Bowers
ॐ