Thanks for choosing health care magic for posting your query.
I have gone through your question in detail and I can understand what you are going through.
The black patches need to be examined to identify whether they are only hyperpigmented areas or they are fungal infection
. Only then the treatment can be ascertained.
Hope I am able to answer your concerns.
If you have any further query, I would be glad to help you.
In future if you wish to contact me directly, you can use the below mentioned link:
Wish you good health,
Dr. Srikanth Reddy M.D.