Skin

"The skin is the largest organ of the body, with a total area of about 20 square feet. The skin protects us from microbes and the elements, helps regulate body temperature, and permits the sensations of touch, heat, and cold.
Skin has three layers: The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone.
The dermis, beneath the epidermis, contains tough connective tissue, hair follicles, and sweat glands.
The deeper subcutaneous tissue (hypodermis) is made of fat and connective tissue.
The skin’s color is created by special cells called melanocytes, which produce the pigment melanin. Melanocytes are located in the epidermis."

Subcutaneous absces

The subcutaneous tissue is composed of loose connective tissue and fat. It lies underneath the skin and above the muscles and the bones. Infections often develop in this layer which may progress to form an abscess. An abscess is a walled off area which contains dead tissues and microorganisms. Abscesses are often caused by contamination through the blood stream or infections penetrating damaged skin. Surgical procedures can often produce subcutaneous abscesses. Staphylococcal aureus, Streptococcus and gram negative organisms can all produce abscess.