I'm suffering from a severe dandruff issue for years I have excessive secretion in my scalp I tried listrene and shampoos nothing worked what can I do?

Strict regimen. Shampoos that contain zinc pyrithione, selenium sulfide, and tar-based shampoos are the best and increasing shampooing frequency helps. Corticosteroid creams are also very helpful in controlling severe dandruff. You can try the 1% over the counter or get a stronger steroid cream,foam,or shampoo from your doctor if that doesn't work. Has what you believe to be dandruff been confirmed by a doctor? .
Dandruff. May respond to shampoon like ketoconazole or zinc and selsun shampoos. Cortisone cream may applied to bald areas every other day. Avoid excessive scalp washing to avoid dryness.