A 28-yeаr-оld wоmаn presents tо the clinic with itching, flаking, and redness on her scalp. She reports that the symptoms have been persistent for several months, with scaly patches and occasional dandruff-like flakes in her hair. The patient has a history of eczema but denies any changes in hair care products. The healthcare provider diagnoses her with seborrheic dermatitis of the scalp. Which of the following is the most appropriate initial pharmacologic treatment for this patient’s scalp dermatitis?