an itchy, scaly, red rash on his left upper chest - zafirlukast

[ArchivalUser]

A 38-year-old man comes to the clinic complaining of a 2-week history of an itchy, scaly, red rash on his left upper chest. He initially treated it with an over-the-counter antibiotic cream. After 5 days with no apparent improvement, he switched to a hydrocortisone cream, which he has been using for the past 9 days. This decreased the redness and itch, but since switching to the steroid, the area of involvement has been growing steadily. He is a school bus driver and he enjoys gardening. He says that he was spending excessive time outside in the sun working in his garden for several weeks leading up to the appearance of the rash. He has been told he has "borderline" diabetes and is currently on a 6-month trial of dietary modification and exercise to see if he can avoid oral hypoglycemic agents. Physical examination reveals an overweight Caucasian man with a scaly, slightly erythematous, 6 by 10 cm plaque which is slightly indurated at the periphery. No other significant lesions are seen. The most appropriate next diagnostic step is to

A. check an antinuclear antibody titer


B. check the patient's thyroid stimulating hormone


C. obtain a skin biopsy


D. perform a KOH preparation of the scale


E. test the patient for the presence HIV antibody

[ArchivalUser]

D. perform a KOH preparation of the scale

[ArchivalUser]

D. perform a KOH preparation of the scale

[ArchivalUser]

correct. ans is tinea corporis.