1. Use a zinc pyrithione shampoo
Zinc pyrithione is an antibacterial and anti-fungal agent, so it can reduce any bacterial or fungal infection on your scalp that may be causing your dandruff due to seborrheic dermatitis. The Malassezia furfur fungi is thought to be partially responsible for dandruff in some people. As such, buy some from your local grocery store or pharmacy and use it instead of your regular shampoo.