i have black colour infection on my skin over the penis for many months i went to doc but not cured. please give suggestion for this
It really depends on what type of infection you have. Fungal infections (take a look at this article for pictures http://www.healthhype.com/jock-itch-pictures-causes-and-treatment.html) can cause discoloration of the skin and this may even be permanent. There are a host of other infections that may be responsible as well and your doctor will be able to advise you further as he/she is familiar with your condition. You should go back for a follow up consultation and inform your doctor about your concerns. If the infection has resolved but just the discoloration is persisting, it may take time (months) before it eases or it could be permanently discolored and very little can be done.