25) Exogenous ochronosis is a localized, blue-black hyperpigmentation in the epidermis, dermis and subcutaneous layers of the skin that can be induced by a number of different chemicals, including hydroquinone.
As indicated earlier, in 1975, the first medical report linking hydroquinone-based skin-bleaching chemicals to irreversible skin damage, exogenous ochronosis, was published by G.
32) The result of this research was that 68 patients (35 percent of the total 195 patients) had exogenous ochronosis.
1990) -- all of whom have linked the use of hydroquinone-based skin-bleaching agents to a permanent skin damage, exogenous ochronosis -- the American, Canadian and European medical communities, to my knowledge, have not undertaken sustained research on the health risks associated with the use of over-the-counter hydroquinone-based skin-bleaching agents.
Even though, to the best of my knowledge, there has never been a credible published research finding which has made a causal link between genetic predisposition and the chance of getting exogenous ochronosis with hydroquinone, medical literature on the issue published in the United States has often suggested a racially-based genetic link between skin-bleaching and exogenous ochronosis.