I have a dark blue color mold on the inside of my foot? What is it?

Hello. Thank you for posting.

There are a variety of things which can cause mold to grow on your skin. Treatment varies accordingly.  The 3 main causes for mold growth on the skin:
excess moisture from humidity or improper drying procedures.
diet; too much yeast, etc.
skin reaction from infection or other outside sources.

Depending upon what the causes of mold growth are, there are several treatments.  Your pharmacist might be able to recommend an over-the-counter treatment.  Consult with a doctor if the condition does not get better or worsens. 

Helena