Paraneoplastic pemphigus is an autoimmune blistering disease associated with an occult or previously diagnosed tumor. Its clinical, histological, and immunological features have been clearly defined. It is characterized by the presence of polymorphic skin lesions and by erosions of the oral and genital mucosas that are refractory to conventional treatments. The histology can be variable and includes acantholysis or lichenoid dermatitis. Circulating autoantibodies are a constant feature and confirm the diagnosis. We describe 2 girls with paraneoplastic pemphigus associated with Hodgkin lymphoma in one and Castelman disease in the other. Both children had oral and genital lesions that did not respond to conventional treatments. Biopsy revealed acantholysis in one and a lichenoid reaction in the other, and immunoassays confirmed the diagnosis. Chemotherapeutic treatment of the underlying disease was performed in both cases, together with high-dose corticosteroids for the skin and mucosal lesions. Both patients died due to respiratory failure. We suggest that paraneoplastic pemphigus, although rare in childhood and adolescence, should be included in the differential diagnosis of periorificial erosive dermatitis; this may assist in the detection of an occult neoplasm.