Information about Rhododenol and vitiligo-like symptoms

■Rhododenol

Rhododenol is an active brightening ingredient developed uniquely by Kanebo Cosmetics. Its chemical name is 4-(4-hydroxyphenyl)-2-butanol and it is a natural ingredient present in many plants including the Nikko maple tree. It is used by Kanebo Cosmetics in synthetic form with a purity in excess of 99 percent. It binds with tyrosinase, the enzyme related to the generation of melanin, whose activation it inhibits, thereby having the effect of preventing the generation of melanin and the appearance on the skin of dark spots and freckles. It may be assumed that the inhibition pattern is competitive inhibition.
Kanebo Cosmetics gained approval from the Ministry of Health, Labour and Welfare for use of Rhododenol as an active quasi-drug ingredient in January 2008.

■Symptoms

White blotching on the skin has appeared in various manifestations, in particular cases exhibiting one or more blotches and cases where the blotches overlap.
There have been cases where blotching has appeared on the neck, the hands and the face upon application of a product to these areas, resulting in inflammation followed by whitening of the affected areas, and other cases where white blotching has occurred without inflammation (or without any subjective awareness thereof).
In the former cases, the symptom appears as relatively clearly defined white blotches, while in the latter cases blotching generally appears without clearly delineated borders.
These symptoms are generally referred to in medical terminology by the term vitiligo, but since this term is unfamiliar to most of our customers, we are using the expression “white blotches” instead.

In many of the reported cases, the symptoms disappeared or started to improve as soon as the consumer stopped using the affected product.
If a user of any of the affected products experiences similar reactions, she or he should contact a dermatologist as soon as possible.

■Skin areas where symptoms are most frequently found

Neck, hands/fingers, cheeks, around the eyes, face line, and other areas to which cosmetics including Rhododenol may have been applied or with which they come into contact.