Acute Bullous Dermatosis and Onycholysis Due to High-Dose Methotrexate and Leucovorin Calcium

The document described three patients who developed severe multiple bullous dermatosis and onycholysis as previously unreported side effects of high-dose methotrexate and leucovorin calcium administration. These side effects were serious enough to disrupt their chemotherapy schedules. Methotrexate sodium's principal toxicities included myelosuppression, mucositis, and hepatitis, with other uncommon toxicities such as alopecia and immune dysfunction. High-dose methotrexate therapy, used in treating histiocytic lymphoma, had more frequent and severe toxicities, including renal dysfunction and vasculitis.