Author: A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand, September 2014.
Skin infections are diseases and conditions caused by or related to an external organism, and can include infestation by mites and insects.
Organisms can also lead to inflammatory skin diseases by provoking an innate or acquired immune reaction to them, eg acne, perioral dermatitis, seborrhoeic dermatitis.
Skin infection is more likely to occur in some circumstances.
Infectious organisms are classified as:
Opportunistic infection is an infection in an immunosuppressed patient that is more frequent or severe because of immune suppression. They can be caused by common infectious organisms (such as Staphylococcus aureus, Candida albicans or Herpes simplex) or ones that rarely infect healthy individuals (such as nocardia, bartonella, atypical mycobacteria, cytomegalovirus, cryptocococcus and other systemic mycoses (deep fungal infections).
Disease can be due to the following classes of organism:
Human skin is not sterile but is colonised by many microorganisms — the microbiota.
Optimal health is required to prevent and treat an infection.
Bear in mind that excessive hygienic measures may be counterproductive if they lead to:
It is not always necessary to actively treat minor skin infections (eg, impetigo, folliculitis, tinea pedis, tinea unguium and herpes simplex), as these will settle on their own, at least in healthy individuals. Tackling infection often enhances natural immunity to them.
However, some infections should always be treated to prevent:
Treatment of infection depends on the cause, its severity and its sensitivity to the proposed agent.
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