If you assume that a company acts rationally there is no reason for arbitrary discrimination, but every reason to adjust wages according to possible costs. I'm sure in the case of wage inequality, this is not the main reason however.
Then you will know whether there is discrimination based on medical conditions or not.
We all know the outcome of this.
The same applies to appearing sick otherwise. I have a particularly white skin. Under the wrong light it can even appear a little gray. Interviews in sunlight go significantly better than under UV light, and I'm pretty sure it's-because they think I'll be ill soon.
Management, everywhere I've ever worked was a band of old boys, playing social poker with eachother. Even the bosses I've had that were minority themselves discriminate. And they were minority only in genes, for example one was a "Turk" ... A christian, grew up in Boston. But yes he's tall and darker and has that broad face. Enjoys football. Discriminates based on religion (granted, given what muslims are doing to Christians in Turkey, I understand. Especially after him showing me some articles concerning the still existing Turkish Armenian Christians)
But it's not like other bosses were different. The problem is the type of person that tends to fill middle management, nothing else.
Since I've started working the main difference is that they lie about it really hard these days.