A 34-year-old woman self-refers to dermatology for evaluation of a very itchy rash that manifested 2 weeks ago on her right arm. She immediately went to an urgent care clinic, where she was diagnosed with shingles and prescribed valacyclovir. This diagnosis was upsetting to the patient, as she was advised to avoid contact with her newborn niece for at least 2 weeks.
Despite the prescribed medication, however, the rash began to pop up in other areas, including her left arm, chest, and face. Through all of this, the patient felt fine: no fever, myalgia, or malaise.
Her husband suggested she seek an appointment with dermatology, which was expedited by a phone call from her primary care provider.
The patient is afebrile and in no acute distress. She is, however, quite upset with the widespread collections of vesicles on mildly erythematous bases, many in a linear configuration. In several areas, there is ecchymosis secondary to scratching.
What’s the diagnosis?