I have tried a number of different prescription shampoos and foams, including Loprox, Luxiq, and Selenium Sulfide 2% lotion, as well as the over the counter
Selsun Blue, T-Gel, and several variants of Head and Shoulders. None of these seem to have any consistent effect on it. The only effective treatment I have discovered so far is exposure to sunlight. This cleared up the scales, but I still had horrible dandruff. After a week or so, the scales returned, and my dandruff is just as bad as ever.