Invasive strep infections and ‘the flesh-eating disease’

This sheet provides parents with facts on invasive streptococcal infections, especially the so-called ‘flesh-eating disease’. Although this condition is not new and is very rare, it has recently captured the attention and imagination of the public, mainly because of the interest from the news media through newspapers, magazines and television talk shows, especially coverage of Lucien Bouchard, Premier of Quebec’s infection. The following are the most commonly asked questions about flesh-eating disease.

What is flesh-eating disease?

Flesh-eating disease refers to a condition known as ‘necrotizing fasciitis’, in which infection occurs in the tissues below the skin, affecting the fat, fascia (coverings of the muscles and tendons) and muscles. The tissues can quickly die because of poor blood supply, possibly leading to the death of the patient.

What causes flesh-eating disease?

It is caused by the bacteria known as group A streptococcus (‘strep’).

Is this the same strep that causes the common strep throat?

Yes, this is the same strep that causes strep throat. Strep can normally be found in the throat or on the skin of up to 10% of children and 1% of adults. However, occasionally, it is able to make it past the normal defenses of the body and enter the blood or other tissues in the body where bacteria do not normally live. This situation is known as invasive strep infection, and can lead to conditions such as pneumonia, bone and joint infections, and rarely necrotizing fasciitis or ‘strep toxic shock syndrome’. Strep toxic shock syndrome occurs when the strep bacteria spread quickly inside the body and release toxins causing shock and failure of many organs and tissues. Necrotizing fasciitis and strep toxic shock syndrome can either occur separately or together. It is only when necrotizing fasciitis is part of the picture that the disease is called flesh-eating disease. There is no evidence that the risk of flesh-eating disease is increased in those detected with this germ in their throat.

In that case, should I be concerned that if my child has strep throat he or she may develop flesh-eating disease?

No. Most cases of flesh-eating disease arise from skin and soft tissue disease, not from strep pharyngitis or strep throat. Millions of North American children get strep throat every year, but less than one child in a million will actually develop flesh-eating disease. Put in context, there is more than 100 times greater risk of dying from a motor vehicle accident and at least a 50% greater risk of getting struck by lightning each year in North America than there is of coming down with flesh-eating disease. Thus, only rarely will strep throat progress to flesh-eating disease.

How can I tell if my child has flesh-eating disease or strep toxic shock syndrome?

The most important thing is to remember that both of these conditions are rare, and are not the same as strep throat. When these illnesses start, there are no specific signs of the disease. Often, children with this condition may have complaints of the ’flu with fever, aches, pains and chills. Some children may have signs of pneumonia, with shortness of breath or a cough. However, most of these signs are nonspecific, and the vast majority of children who have these symptoms are more likely to have influenza or something other than strep toxic shock syndrome. With flesh-eating disease, there is often a complaint of severe pain that is disproportionate to what can be seen on examination of the area of body involved, and the area involved may be exquisitely sensitive to touch. In any case, if you are concerned about your child, it is wise to have him or her examined by your paediatrician or family doctor.

I have heard that children with chickenpox or with skin conditions are prone to getting flesh-eating disease. What should I do if my child develops chickenpox?

Yes, it is true that children with chickenpox have a higher chance of developing necrotizing fasciitis than those who do not. However, relative to the number of children who come down with chickenpox each year, necrotizing fasciitis is very uncommon, and nothing needs to be done for children who have chickenpox unless they develop the signs mentioned above or they develop high fever beyond the third day after the onset of chickenpox or any fever beyond the fourth day after the onset of the disease.

If a member of my family comes down with flesh-eating disease or strep toxic shock syndrome, are the other members of my family at risk of developing it as well?

There is some evidence that close contacts of someone with these conditions (usually persons with more than 4 h of contact a day) are at increased risk of developing these conditions compared with those who are not in close contact. Although this risk is still low, most health authorities in Canada suggest treating family members to decrease the risk. Your doctor will advise you about the best treatment.