Pernio as the presenting sign of blast crisis in acute lymphoblastic leukemia.

A previously healthy 5-year-old girl presented with acute onset of blue toes and red spots on the nose and fingers. The striking nature of these lesions, along with the finding of submandibular lymphadenopathy, prompted further evaluation. Laboratory findings were remarkable for anemia, high transaminase levels, and high blast count. Histopathologic findings were consistent with early pernio. Further examination revealed acute B-cell lymphoblastic leukemia. Treatment of the leukemia led to resolution of the pernio.