Hello,
Since you are having scattered patches of this depigmentation on the legs, it can be vitiligo. It is a pigmentation disorder in which melanocytes (the cells that make pigment) in the skin are destroyed. As a result, white patches appear on the skin in different parts of the body. Diagnosis can be confirmed by external examination, blood tests to check skin cell count for melanocytes and biopsy of the skin patches.
Once the diagnosis is confirmed, treatment can be planned. It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist/ urologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
It sounds like vitiligo. It's pretty common. My mom has it on her arms. I've heard that sometimes you can get white spots from a fungus, so that's a possibility. If it's a fungus you could try antifungal cream to see if that would help. If it's vitiligo, you may need to see a doctor to see if anything can be done.