Pine-bark lichen

Lichen marked by a thickening of the skin that gives the appearance of pine bark. Pine bark lichen is attributed to factors such as invasion of exterior wind-cold, disharmony between provisioning and defense and between the thoroughfare (chōng) and controlling (rèn) vessels, and provisioning-defense depletion. It starts with red macules of various sizes, covered with white scales that slough away to reveal bleeding speckles and cause itching. It occurs on corresponding positions on the outer (yáng) aspect of the limbs. See lichen.