Discoid lupus erythematosus following herpes zoster

The isomorphic response is the appearance of new lesions from a preexisting skin condition at a site of trauma. Discoid lupus erythematosus (DLE) may develop on traumatized skin and also may arise at sites of a prior cutaneous eruption. We report the case of a 20-year-old woman with a history of systemic lupus erythematosus (SLE) and DLE who developed a painful, multidermatomal, vesicular rash on the left breast and back consistent with herpes zoster (HZ) during treatment with systemic immunosuppression. Four months after the HZ resolved, the patient developed new-onset DLE lesions within the prior HZ-affected dermatomes. Our case is one of few reports of an isomorphic response in an immunosuppressed young woman with a history of SLE and DLE. When HZ presents in this patient population, close monitoring of the HZ-affected sites for any evidence of DLE is recommended. Topical corticosteroids should be applied to the involved areas at the earliest appearance of such lesions to further prevent potentially scarring DLE lesions.