It sounds like you have a case of “seborrheic dermatitis” of the eyebrow. This is more commonly known as “dandruff.” Treatment should be with an anti-dandruff shampoo such as: Treat by lathering dandruff shampoo such as Head and Shoulders (pyrithione zinc based), Nizoral (ketokonazole based), or Selsun Blue (selenium sulfide based). If symptoms do not resolve or worsen, consult a dermatologist.