Induration refers to the thickening and hardening of soft tissues of the body, specifically the skin, and is the result of an inflammatory process caused by various triggering factors. It is a deep thickening of the skin that can result from edema, inflammation, or infiltration, including by cancer. Indurated areas commonly appear on the hands and face but can also be found on the chest, back, abdomen, breasts, or buttocks. Induration can be caused by various medical conditions that trigger an inflammatory process, including infections, infiltration by malignant cells, and other polysystemic conditions. Panniculitis, an inflammation of the subcutaneous (i.e., under the skin) fat tissue, can also cause induration in the affected areas. Similarly, an inflammatory process triggered by inflammatory disorders (e.g., Crohn disease), trauma, exposure to cold, or connective tissue disorders (e.g., lipoatrophy) can cause thickening, formation of firm nodules, and plaques on the skin.