Abstract
We describe a patient who was treated with high-dose intravenous and intrathecal methotrexate for acute lymphoblastic leukemia, and who manifested a false photosensitivity reaction with no prior evidence of sun exposure. This patient later experienced delayed transient hemiparesis following methotrexate administration, although without long-term sequelae. The etiology of these events is obscure, but suggestive of a vasculitic or immune-mediated reaction to methotrexate.