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.
Glycerol and Fatty Acids. One major class of lipids is called glycerolipids. Glycerolipids are composed of glycerol and fatty acids. Glycerol, whose structural formula is shown at right, has three carbon atoms, each of which has a hydroxyl (-OH) group bound to it.Fatty acids are fairly long linear hydrocarbon chains with a carboxylic acid group at one end.lycerol, whose structural formula is shown at right, has three carbon atoms, each of which has a hydroxyl (-OH) group bound to it. Fatty acids are fairly long linear hydrocarbon chains with a carboxylic acid group at one end.