Itchiness, black patches. The spred!

My both feet and shin area have developed black itchy patches. Itching is uncontrollable when particular area gets wet. My palm, inner fingers area also have become itchy. The problem is now spreading to wrist area, where when i itch, white patches appears. Also my armpit areas have become itchy recently and started develop painful pimples. It was started with shin area patch, for which i had consulted my native doctor. I followed his medication for some months, but due to unavailability of time i couldn't consult him further also because i work in some other city. Earlier it felt like it has been controlled with my native doctor's medication, but now it is spreading irritatingly all over my body. My groin area also itches irritatingly. I am a little overweight and have digestion problem. I had done my blood sugar and lipid levels checked last month, which came out to be normal. Kindly suggest some quick remedies to get rid off the itch as it is irritating, and how to control the spred