ABSTRACT
Macules are flat areas of discoloration up to 1 cm (0.4 in) in diameter,whereas patches are larger than 1 cm in diameter. Changes can involve increased blood flow (erythema), extravasated blood (hemorrhagic petechiae and ecchymoses), or pigment changes. Erythema can be distinguished from hemorrgage by blanching on digital pressure or using a glass slide (diascopy).
