Skin infection

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

A skin infection can be differentiated according to the depth of the infection into the skin layers (epidermis, dermis and subcutaneous tissue).

• Impetigo: high contagious superficial skin infection that affects the epidermis; it is most common among children age 2–6 years. It is classified as bullous and non-bullous, being the latter the most common presentation of impetigo.
  • Bullous impetigo: small vesicles that enlarge to a bullae, commonly associated with S. aureus infection
  • Non-bullous impetigo: characteristic "honey-crust" lesions, can be caused by S. aureus or Streptococi.

• Ecthyma: severe form of impetigo with ulceration of the epidermis and formation of crust. The legs, thighs and buttocks are the most common affected area.

• Erysipela: 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.

Skin Appendage Infection

• Folliculitis

• 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.