Unilateral Mediothoracic Exanthem – Report of the Third Patient in the Literature

Abstract

Background: We have previously described two patients with a paraviral exanthem known as unilateral mediothoracic exanthem, which we believe to be intimately related to asymmetric periflexural exanthem and/or unilateral laterothoracic exanthem. Presentation of Case:   A 20-year-old male presented with an erythematous belt of erythema and papules on the left anterior aspect of the thoracic cage. The lesions jumped across the dermatomes from T4/T5 laterally to T6 medially, and stopped abruptly at the midline. Vesicles were not seen for the entire course of the eruption. Lesional histopathology revealed perisudoral lymphocytic infiltrates, which is a characteristic, though not pathognomonic, feature of asymmetric periflexural exanthem / unilateral laterothoracic exanthem. Complete rash remission was noted in two weeks. Conclusion: The rash distribution and the lesional histopathological changes are compatible with unilateral mediothoracic exanthem, a variant of two paraviral exanthems. This is the third reported patient with unilateral mediothoracic exanthem.