A case of vesiculobullous dermatomyositis with anti-NXP-2 antibody without malignancy

Vesiculobullous dermatomyositis (VD) is a rare manifestation of dermatomyositis (DM) and has been suggested to be associated with malignancy. Although the myositis-specific autoantibodies are associated with distinct clinical presentations of DM, those associated with VD remain unclear. Here, we present the case of a 54-year-old man with VD who tested positive for antinuclear matrix protein 2 (NXP-2) antibodies, one of the DM-specific autoantibodies. Serological and histopathological findings did not support autoimmune blistering disease. Physical and histological findings suggested that the severe oedema in combination with the interface dermatitis of DM contributed to blister formation. Although a systemic examination was performed, no evidence of malignancy was found. Following initiation of immunosuppressive therapy, the patient showed significant improvement in both skin lesions and myositis. This case represents the first report of anti-NXP-2-positive VD without malignancy or autoimmune blistering disease. Subcutaneous oedema, a characteristic feature of anti-NXP-2-positive DM, could be related to the formation of VD.