Suggest Medication For Remaining Dark Spots On Arm After The Rashes Were Cured

Hi doctor, Some days back I developed some rashes on my right arm. The rashes then got cured by themselves and the areas have faded. I m not a fair skinned person so areas appear as spots on my arm. I consulted a doctor and he suggested to use Momate Cream. But the spots are still there. Please help. Thanks & Regards Sonia Sarkar