A 22-year-old, healthy Caucasian man presents to the emergency department with scaly, verrucous rash involving the side of his nose (image), his left shoulder, the right side of his back, and the left posterior aspect of his thigh. He has recently moved to California's Central Valley but denies having any unusual exposures or medical problems and is not taking any medications.
The review of symptoms yields negative findings for fevers, night sweats, and chills. Methicillin-resistant Staphylococcus aureus (MRSA) is initially diagnosed, and the patient is presumptively treated with trimethoprim-sulfamethoxazole and rifampin and discharged home. Several weeks later, he returns to the clinic because the "rash" was not improving and he now has night sweats and arthralgias. Consultation with a dermatologist leads to biopsy of the lesions.
What is the diagnosis?
Hint: The patient developed symptoms after moving to California's Central Valley.
Rachel U. Lee,