In adults, eczema occurs most frequently on the hands and elbows, and in bending areas such as the inside of the elbows and back of the knees. In young children, eczema is often seen on the elbows, knees, face, neck, and scalp. Signs and symptoms of atopic eczema include: 1  Itchiness. 2  Skin redness.
Sphingolipids are composed of a backbone of sphingosine which is derived itself from glycerol. Sphingosine is N-acetylated by a variety of fatty acids generating a family of molecules referred to as ceramides. Sphingolipids predominate in the myelin sheath of nerve fibers.
Phospholipids. Phospholipids are like fats but they have two fatty acids and a phosphate group joined to glycerol. The fatty acid tails are hydrophobic but the phosphate part is hydrophilic. This is an important feature of these molecules. More about phospholipids when we cover membrane structure.