Case Report: Post herpes zoster comedones: A new entity under Wolf’s isotopic response

Abstract

The emergence of a completely new skin condition at the precise location of a different, unrelated and previously healed skin disease is referred to as a "Wolf's isotopic response". It is also referred as post-herpetic isotopic response because it typically manifests after contracting the varicella-zoster virus causing herpes zoster. Wolf’s isotopic response is a rare, unique and widely accepted phenomenon. In this study, we discuss the various theories proposed behind its etiology. Further studies can help us understand the pathomechanism behind the localization of skin diseases thereby, helping us manage the condition effectively. Here, we describe a case of a 36-year-old male who presented in the outpatient department with multiple open and closed comedones distributed along the site of T2 dermatome previously infected by herpes zoster infection. Dermoscopic examination revealed multiple, round, brown-colored follicular keratinous plugs with peri-lesional erythema. Histopathological analysis showed a large dilated follicular canal containing orthokeratotic stratum corneum consistent with closed comedone formation. The patient was diagnosed with post-herpetic zosteriform comedones and was prescribed oral isotretinoin 20 mg, topical tretinoin 0.05% cream with a moisturizer and asked to follow up regularly. The lesions gradually healed over a five-month period. In our case, timely medical intervention helped preventing the further progression of the disease. However, further studies involving large sample sizes can help us identify the underlying mechanism behind this phenomenon.