Telangiectasia macularis eruptiva perstans (TMEP) is a form of mastocytosis. It is an uncommon condition, particularly in children. The disorder is characterized by telangiectatic macules and generally has a good prognosis, with little tendency to urticate or cause constitutional symptoms. We report a girl who presented at age 2 with a 6-month history of erythematous macules on her arms and legs. The lesions were larger and possessed a more angular configuration than classic telangiectases. They slowly spread to her torso and face; there were no associated constitutional symptoms. Histopathologic examination showed dilated capillaries and increased numbers of mast cells, consistent with TMEP. Mastocytosis should be considered in patients presenting with telangiectatic lesions that are atypical in appearance, distribution, or onset.