Persistent forehead acne. Could it because of my hair hygiene?

I have medium long hair that touches the forehead and the temples. I usually wash it twice a week or so because it becomes frizzy with the shampoo I have. My hair is quite oily. But my acne (both inflammatory and comedones) persist despite many months of using tretinoin 1% and azelaic acid and it mostly does so on the forehead. I sometimes get tiny pimples here and there on the other areas but that's all. Could it be because of my haircare?