Wolf's Isotopic Response: A Rare Case of Terra Firma‐Forme Dermatosis on Resolved Psoriatic Plaques

Terra firma-forme dermatosis is a benign condition characterised by asymptomatic hyperkeratotic, dark papules or plaques. The diagnosis may be confirmed by firmly rubbing the lesions with 70% isopropyl alcohol, resulting in resolution of the lesions. Wolf's isotopic response refers to the development of a new dermatosis in the same location that a previous, healed, unrelated skin condition occupied. We report the case of a patient developing Terra firma-forme dermatosis at the site of resolved psoriatic plaques.