A 24-year-old female presents with a pruritic rash on her trunk and upper thighs. Patient states that, six days ago, she noticed a single small erythematous patch on her abdomen which gradually increased in size. Over the next few days, similar patches appeared on her back and thighs. Patient denies any recent history of fever, chills, upper respiratory tract infection, or any similar symptoms in the past. No other significant past medical history. Current medications are drospirenone/ethyl estradiol 3 mg/0.03 mg 1 tablet orally daily. Patent is sexually active with a single male partner for the last two years but says they use condoms inconsistently.

Her temperature is 37.0℃ (98.6℉), blood pressure is 120/80 mm Hg, pulse is 72/min, respiratory rate is 15/min, and oxygen saturation is 99% on room air. On physical examination, patient is alert and cooperative. There is a symmetric macular rash present over the patient’s abdomen, chest, back, and upper thighs, distributed in a “fir tree” pattern. The lesions have an average diameter of 1.5 cm and are mildly erythematous with a central clearing and darker periphery. There is also a fine scaling present within the borders of the lesion. A similar larger patch is present on the patient’s abdomen. It is ovoid, 6 cm in diameter, slightly elevated, and has the same scaling as do the smaller lesions. There is no exudate, drainage, ulceration, or lymphadenopathy present.

Which of the following is the best course of treatment for this patient’s most likely diagnosis?

A. Benzathine penicillia.

B. Cetirizine

C. Oral prednisone

D. Topical ketoconazole

E. Oral nystatin