A 3-year old girl presents with a 4-week history of rash on her left arm, flank, and thigh. The rash is non-pruritic and non-painful. The patient is taking no medications and is up-to-date on all immunizations. Her medical and family history are noncontributory. One week before the onset of the rash, the patient’s parents had taken her to her pediatrician because she had a runny nose and sore throat. A URI was diagnosed.
Discrete 1- to 2-mm erythematous papules unilaterally were distributed across the left axillae, arm, flank, and thigh.
What’s Your Diagnosis?