The skin is the largest organ of protection and defense. It is a sensory organ. It serves for thermoregulation, secretion and excretion. The skin plays an important role in the elimination of toxins and can assist the kidneys in their work. It evacuates the waste products that are classified as crystals. They are soluble in liquids and are evacuated in the form of sweat through the sweat glands.
Crystals are the residues of the metabolism of food rich in protein, such as meat, fish, eggs, dairy products, legumes and cereals. Uric acid and urea are part of the group of crystals. These may also result from an excess of refined sugar or very acidic food. Other types of waste products and toxins are excreted in the form of rashes.