What is responsible for her pruritic eruption?

A 63-year-old female presented with a outbreak of slightly itchy and slightly tender papular and vesicular eruption on the inner aspect of the left that appears to follow the dermatome of 1-day duration. She has received the shingles vaccine 3 years ago and admits to gardening as a hobby. She is otherwise healthy.

What is responsible for the pruritic eruption? 

A. Poison ivy

b. Herpes zoster

C. Dermatitis herpetiformis

D. Bullous lichen planus

E. Factitial dermatitis

(Answer and discussion on next page)

Answer: Poison ivy

This patient was initially thought to have shingles and was placed on antiviral therapy. When her rash progressed over the next 2 days, additional history was obtained that this had occurred 1 day after trimming bushes and doing yard work. A prednisone taper provided much needed relief. Dermatitits herpetiformis should be symmetrical and bullous lichen planus is seen with the background of lichen planus lesions. It is difficult to factitiously produce discrete vesicles as seen here. ν