What Explains This Asymptomatic Rash?
David L. Kaplan, MD—Series Editor
Kaplan DL. What explains this asymptomatic rash? Consultant. 2017;57(12):692,694.
This 83-year-old woman presented with a 1-week history of an asymptomatic rash that wrapped around the right side of her trunk. At the visit, the rash appeared as a linear group of eroded lesions with overlying crust. She had received the shingles vaccine 10 years ago. She was otherwise healthy for her age.
Answer: Herpes zoster
This patient had an asymptomatic case of herpes zoster. The diagnosis was based on the dermatomal distribution of the lesions, which responded to appropriate antiviral therapy without residual complications.
Given that the herpes zoster vaccine works best in persons aged 60 to 69 years, works only approximately 50% of the time, and lasts for approximately 5 years, this older patient was for- tunate to have retained some residual effect of the vaccine, resulting in an atypical presentation of painless, sparse lesions.
Staphylococcal infection and ecthyma would be expected to be painful. Lichen striatus does not ulcerate. The location of the patient’s lesions in a difficult-to-reach area made excoriations or factitial dermatitis less likely diagnoses.
David L. Kaplan, MD, is a clinical assistant professor of dermatology at the University of Missouri–Kansas City School of Medicine in Kansas City, Missouri, and at the University of Kansas School of Medicine in Kansas City, Kansas. He practices adult and pediatric dermatology in Overland Park, Kansas.