Health Information and Self Care Advice for Scotland

Staphylococcal infections

Introduction

Staphylococcal infections are a common group of infections caused by the staphylococcus bacteria. There are several different strains of staphylococcal bacteria, the most common being staphylococcus aureus. Different strains of the bacteria cause different infections. Staphylococcal infections mainly affect the skin, but can cause serious internal disorders.

Staphylococcal bacteria clump together on the skin. They are normally harmless unless they become very heavily concentrated on the skin surface or they are able to enter the body through a break in the skin. About 20-30% of people carry staphylococcal bacteria on the surface of their skin without developing any infection. Others carry it in other parts of the body without becoming ill, including the nostrils, mouth and throat, the breasts, and the genital, urinary and upper respiratory tracts.

If staphylococcal bacteria build up in large quantities on the surface of the skin or are able to enter a break in the skin, they can overcome the body's natural defences and cause skin infections. These include:

• boils (pus-filled infections of hair follicles),
• abscesses (collections of pus in pockets under the skin),
• styes (infection of glands in the eyelid),
• carbuncles (infections larger than an abscess, usually with several openings to the skin),
• cellulitis (infection of the skin and the fat and tissues that lie immediately beneath it), and
• impetigo (a skin infection that produces pus-filled blisters).

Although staphylococcal bacteria usually infect the skin, if they are able to enter the bloodstream they can affect almost any part of your body. When staphylococcal bacteria enter the bloodstream they can cause:

• septic shock,
• severe joint problems (septic arthritis),
• bone marrow infection (osteomyelitis),
• internal abscesses anywhere within the body,
• inflammation of the tissues that surround the brain and spinal cord (meningitis),
• lung infection (pneumonia), and
• infection of the heart lining (endocarditis).

Some strains of staphylococcal bacteria produce toxins (poisons) when they grow and reproduce. If you eat food contaminated with staphylococcal bacteria these toxins can cause staphylococcal food poisoning. The toxins can also cause scalded skin syndrome and, very occasionally, toxic shock syndrome.

Last updated on 27 June 2007 04:48 PM