Keratin Keratin Keratin () is one of a family of fibrous structural proteins. It is the key structural material making up hair, horns, claws, hooves, and the outer layer of human skin. Keratin is also the protein that protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. The only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin derives from Greek ' from '
Skin infection Skin infection Infection of the skin is distinguished from dermatitis, which is inflammation of the skin, but a skin infection can result in skin inflammation. Skin inflammation due to skin infection is called "infective dermatitis." Bacterial skin infections affected about 155 million people and cellulitis occurred in about 600 million people in 2013. Bacterial skin infections include: Fungal skin infections may present as either a superficial or deep infection of the skin, hair, and/or nails. As of 2010, they affect about one billion people globally. Parasitic infestations, stings, and bites in humans are caused by several groups of organisms belonging