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Question 23#

A 21-year-old woman presents with an annular pruritic rash on her neck. She explains that the rash has been present for the past 3 weeks and that her roommate had a similar rash not long ago. Physical examination is remarkable for a 20-mm scaling, erythematous plaque with a serpiginous border.

Which of the following is the most appropriate initial treatment for this condition? 

a. Griseofulvin
b. Oral cephalexin
c. Topical mupirocin ointment
d. Topical ketoconazole
e. Hydrocortisone cream

Correct Answer is D

Comment:

Tinea corporis (ringworm) is a dermatophyte that causes a superficial infection of the skin. Tinea corporis clinically presents as an erythematous scaly plaque with a central clearing and serpiginous border. It is usually acquired through contact with an infected individual or animal. Initial treatment involves application of topical antifungals such as ketoconazole, clotrimazole, miconazole, toconazole, econazole, naftifine, terbinafine, or ciclopirox olamine cream. The cream should be applied to an area 3 cm beyond the edge of erythema, and topical treatment should be continued for 1 week after clinical clearing has occurred. More severe infection that is unresponsive to topical therapy, or one involving the scalp, nails, or beard area, should be treated systemically with oral griseofulvin, itraconazole, or terbinafine. Cephalexin and mupirocin are antibacterial agents used for superficial infections of the skin caused by Staphylococcus aureus such as folliculitis or impetigo. Hydrocortisone is a weak corticosteroid that can actually exacerbate a fungal infection. Potassium hydroxide (KOH) skin prep would confirm the diagnosis.