Immunohistopathological Analysis of Frizzled-4-Positive Immature Melanocytes from Hair Follicles of Patients with Rhododenol-Induced Leukoderma

A study conducted in July 2013 found that the repeated application of rhododendrol, a melanin synthesis inhibitor used in skin-whitening cosmetics, led to skin depigmentation in approximately 16,000 consumers, affecting areas such as the face, neck, and upper limbs. The condition, known as RD-induced leukoderma, was investigated through various biochemical, cytological, and immunological studies. These studies revealed that the depigmentation was not only due to the cytotoxic effects on melanocytes but also involved subsequent immune reactions.