It may not be dandruff..It may be sebopsoriasis....Send photos, of the affected area for accurate diagnosis and treatment.

Dandruff occurs because of opportunistic growth of normal commensal of skin known as pityrosporum species , which can be enhanced because of environmental conditions, excess sebum production, sweating, etc , so it's bound for recurrence if proper issue is not addressed, visit a nearby dermatologist for thorough examination and treatment plan accordingly