"IF" you have some one massage with the thumb in a circular motion for 10 minutes once a week or maybe 3X a week, the books would suggest in 3-5 massages. Depending on the exact location you could look at a REFLEX chart and see that this would indicate a congested area in your body and once the purple was gone, so would be the health problem associtaed with it.
I would also de-worm and all the other standard things if possible or at least use a few drops of oegano daily or rub the oregano on directly just in case it had anything to do with a ringworm.