we've had success with a client using this mineralfusion dandruff shampoo - the flaking has dissipated and his forehead remains clear. would be worth a try - it's available at whole foods and rainbow, and does not have any overpowering fragrance!
double check the shampoo bottle's label to make sure it matches this list:
2% salicylic acid (to control dandruff)
aqua, aloe barbadensis (leaf juice/jus de feuilles), sodium laurylglucosides hydroxypropylsulfonate, coco-betaine, sodium methyl cocoyl taurate, decyl glucoside, glycerin, panthenol, malachite (extract/extrait), smithsonite (extract/extrait), rhodochrosite (extract/extrait), hematite (extract/extrait), dimethicone, undecylenic acid, mica, titanium dioxide, melaleuca alternifolia (tea tree leaf oil/l'huile de feuilles), guar hydroxypropyltrimonium chloride, origanum vulgare (oregano leaf extract/extrait de feuilles), citric acid, maris limus, sodium benzoate, potassium sorbate, ethylhexylglycerin, natural fragrance. *certified organic