Terra firma-forme dermatosis: an often underdiagnosed benign condition.

Abstract

Terra firma-forme dermatosis is an idiopathic acquired condition characterized by asymptomatic brown plaques that are easily removed by rubbing alcohol. It manifests as slightly raised, brownish or blackish, hyperkeratotic and asymptomatic plaques. Lesions are typically located on the neck, face, and trunk, unilaterally or bilaterally. This skin disorder affects people with good hygiene habits and the lesions are not removed with soap and water. Terra firma-forme dermatosis must be differentiated from dermatitis neglecta due to inadequate frictional cleansing, confluent and reticulated papillomatosis, acanthosis nigricans, and “dirty neck syndrome” of atopic dermatitis. The diagnosis is clinical and is confirmed by the disappearance of the lesions following vigorous rubbing with a gauze soaked in alcohol. While a benign condition, misdiagnosis can lead to unnecessary endocrinological tests and social disapproval due to the dirty appearance.