An 8-Year-Old Girl Is Brought to the Office for Evaluation

An 8-year-old girl is brought to the office for evaluation of a skin rash on her upper back.  The rash is not painful but is mildly pruritic.  She has no prior medical conditions, takes no medications, and is up to date with vaccinations.  Vital signs are within normal limits.  Right scapular area skin examination is shown in the exhibit.
 
The remainder of the examination is normal.  Which of the following is the most likely cause of this patient's current condition?

A) Deep tissue invasion by normal skin flora
B) Epidermal damage from excessive sun exposure
C) Immunologic response to bacterial pharyngitis
D) Microbial infection of keratinized structures
E) Proliferation of pathogen transmitted by tick bite