Paraneoplastic pemphigus misdiagnosed as juvenile dermatomyositis: A case report.

Paraneoplastic pemphigus (PNP) is a rare autoimmune skin disease closely related to tumors, characterized by a maculopapular rash with mucosal pain, bronchiole occlusion, and respiratory failure may occur over time, even resulting in death. We report a rare case of a child with autoimmune PNP misdiagnosed as juvenile dermatomyositis (JDM), and summarize the key points of differentiation of clinical manifestations and auxiliary examinations of PNP and JDM. When the diagnosis is not clear because the patient has features not typical of JDM, then skin biopsy and other diagnostic studies should be considered prior to any immunosuppressive therapy, as this could potentially obscure and delay the diagnosis of malignancy.