Erythematous Macules. Erythema

Abstract

The intensity of an erythema depends on the room temperature where the patient is being examined and on the patient’s position, whether lying or standing, which explains its variability. For example, in certain angiosarcomas of the face, erythema becomes apparent only when the patient tilts her head downwards for 1 min (known as tilt test). Erythema can be permanent or paroxysmal. It can display a notable configuration, annular or grid-like (livedo). Numerous tones of red (ranging from pink to violet) exist and are of great semiological value to the experimented physician in the orientation of diagnosis. The association of erythema, pain, edema, and increased temperature is characteristic of inflammation in the broad sense. Erythemas of the folds (also known as intertrigo), the extremities, the face, the scrotum, or the buttocks in children often have specific causes and are covered in Chap. 19. Causes of exanthemas are covered in Chap. 20 and causes of erythroderma are summarized in Chap. 21.