Milia en plaque manifesting as a post-herpetic isotopic response.

Isotopic response in dermatology refers to the development of a new primary dermatosis at the site of a previous reaction such as cutaneous herpes virus infection. We report a 63-year-old woman with a recent history of a bullous drug eruption treated with prednisone who presented with herpetic dermatitis and subsequent milia en plaque. This unique case represents a novel presentation of milia en plaque manifesting as a complication from post-herpetic isotopic response and highlights the wide array of isotopic responses that can occur following a cutaneous herpes simplex infection.