Skin and soft-tissue infections

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alejandro Lemor, M.D. [2]

Click on each condition for more information about that particular infection

	Layer	Condition	Definition
File	Epidermis	Impetigo	High contagious superficial skin infection that affects the epidermis. It is classified as bullous and non-bullous, being the latter the most common presentation of impetigo. Bullous: small vesicles that enlarge to a bullae, commonly associated with S. aureus infection. Non-bullous: characteristic "honey-crust" lesions, can be caused by S. aureus or Streptococi.
		Ecthyma	Severe form of impetigo with ulceration of the pidermis and formation of crust. The legs, thighs and buttocks are the most common affected areas.
	Dermis	Folliculitis	Inflammation of a hair follicle.
		Furuncle	Infection of a hair follicle, also known as boil.
		Carbuncle	Collection of furuncles with a larger area of involvement and may extend to the subcutaneous tissue.
		Erysipelas	Superficial skin infection with a clear line of demarcation between involved and uninvolved tissue and raised lesions above the level of the surrounding skin; affects the epidermis and upper dermis.
		Cellulitis	Diffuse skin infection that involves the deeper dermis and the subcutaneous fat tissue. It is classified as non-purulent and purulent cellulitis. Non-purulent cellulitis: with no purulent drainage or exudate and no associated abscess. Purulent cellulitis: associated with purulent drainage or exudate in the absence of a drainable abscess.
	Subcutaneous tissue
		Necrotizing fasciitis
	Muscle	Myonecrosis

Table adapted from Rook's Textbook of Dermatology, Seventh Edition and Clinical Infectious Diseases 2005; 41:1373–406