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.
Figure 1: The lipid bilayer and the structure and composition of a glycerophospholipid molecule. (A) The plasma membrane of a cell is a bilayer of glycerophospholipid molecules. (B) A single glycerophospholipid molecule is composed of two major regions: a hydrophilic head (green) and hydrophobic tails (purple).(C) The subregions of a glycerophospholipid molecule; phosphatidylcholine is shown as an example.ith few exceptions, cellular membranes â including plasma membranes and internal membranes â are made of glycerophospholipids, molecules composed of glycerol, a phosphate group, and two fatty acid chains.