Why simple school sores often lead to heart and kidney disease in Indigenous children

December 11, 2017 by Jackson Thomas, Erin Walker, Gregory Peterson And Nathan M D'cunha, The Conversation
Impetigo happens when itching causes the skin to break and let in disease-causing bacteria. Credit: shutterstock.com

Impetigo, also known as school sores, is a highly contagious bacterial skin infection that occurs in children far more frequently than adults. It is one of the most common bacterial infections in children aged two to five years. Impetigo happens when a break in the skin, from scratching an insect bite for instance, lets in disease-causing bacteria.

The bacteria responsible for impetigo are Staphylococcus aureus (S. aureus or staph) and Streptococcus pyogenes (S. pyogenes or group A strep). People with diabetes or other conditions that may affect the immune system, such as HIV , and those on medications that suppress immunity, are more susceptible.

While the infection itself is treatable, if left untreated it can lead to more serious conditions such as cellulitis (infection of the inner layers of ) or abscess (painful collections of pus that build up under the skin). It can also progress to kidney disease, or it could cause acute rheumatic fever, which can affect the heart, joints, brain or skin.

Around 162 million worldwide suffer from impetigo at any one time. They mostly live in resource-poor tropical countries or underprivileged populations in developed countries. In Australia, about 15,000 Indigenous children are estimated to suffer from impetigo – representing 40% of children in Indigenous communities.

Causes and symptoms

Impetigo can occur on top of other skin conditions, particularly itchy ones like eczema, scabies, insect bites, and head lice. Scratching the skin can break it and let the disease-causing bacteria in. A sore can be infectious for as long as it is weeping fluid, as the fluid and crusts of the sore contain infectious bacteria.

The time between becoming infected and developing symptoms is around four to ten days. Contact with the sore, or with things that have been in contact with the sore, can spread the infection to other people.

There are two forms of impetigo: non-bullous and bullous. Non-bullous, also known as the crusted form of impetigo, accounts for about 70% of all cases and can be caused by both S. aureus and S. pyogenes. It has a thick, soft, yellow crust below which is often a wet, red area.

Crusted forms of impetigo are the most common. Credit: Wikimedia Commons

Non-bullous impetigo spots grow slowly and are smaller than the fully grown spots of bullous, or blistering, impetigo. They are not usually painful but can be itchy. The lesions generally appear on the face and extremities, often at the location of already broken skin, such as an insect bite or eczema.

The bullous (blistering) form of impetigo is characterised by the formation of a large, fluid-filled irritating blister under the skin. It is caused exclusively by S. aureus and usually occurs where two skin surfaces touch or rub together, such as the armpits.

The blisters grow rapidly in size and number. They burst quickly and leave slightly wet or shiny areas with a brown crust at the edge. Those spots continue to grow quickly even after they break open and can be many centimetres wide. They are not usually painful but can be itchy.

What are the treatments?

As impetigo is highly contagious, good hygiene practices are essential for stopping the spread of infection. These include washing hands with soap, washing of infected clothes and towels, and covering the sore with a sticking plaster.

It's also recommended that the infected child be kept away from other children and school for 24 hours after starting treatment.

Impetigo is generally considered a mild disease that can resolve without treatment after a few weeks. But because it can cause more serious conditions, the child should be examined by a doctor and treated with appropriate antibiotics.

Topical antibiotics (creams) like mupirocin are recommended for mild forms of the infection. Oral antibiotics are used in more severe cases of impetigo, such as when multiple sores are present, or when topical treatments have been ineffective. The treatment should continue until all sores are completely healed. With treatment, symptoms are likely to be improved or cleared up after seven days.

Blistering impetigo infections usually occur where two skin surfaces touch, like the armpits. Credit: Wikimedia Commons

What happens if it's not treated?

A possible consequence of untreated impetigo is an autoimmune kidney disease called acute post-streptococcal glomerulonephritis (APSGN). It's not frequently seen in developed countries but one estimate suggests that more than 390,000 children in less developed countries are affected, compared with about 13,000 children in more developed countries.

In Australia, data collected from 1991-2008 in the Northern Territory revealed that 95% of cases occurred in Indigenous Australians, with 98% of affected individuals living in remote locations. The average age was seven years old, with children younger than 15 accounting for 88% of all cases.

Given the association between APSGN and chronic kidney disease, it is important that predisposing skin infections are treated promptly and appropriately, and the risk of transmission or recurrences is minimised. Around 97% of deaths from APSGN occur in resource-poor countries or communities.

Acute rheumatic fever is another potential consequence of untreated impetigo. It is an autoimmune response to an untreated group A strep infection, and repeated episodes can damage the heart, leading to .

Both rheumatic fever and rheumatic heart disease are preventable and generally not seen in industrialised countries. But rates of rheumatic fever and rheumatic heart diseases in Indigenous communities are up to 26 times those in non-Indigenous populations.

Between 1997 and 2013, 97% of patients diagnosed with in the NT were Indigenous, despite Indigenous Australians representing about 30% of the NT population. Similarly, 94% of people diagnosed with rheumatic heart during this time were Indigenous, and Indigenous patients were younger than the non-Indigenous patients.

Poor hygiene, close living and lack of access to medical care are associated with impetigo and its related complications. Resources that help lessen these risk factors will also reduce the burden of impetigo and the diseases that can develop as a consequence.

Explore further: How to prevent spread of the skin infection impetigo

Related Stories

How to prevent spread of the skin infection impetigo

November 27, 2016
(HealthDay)—Impetigo is a contagious skin infection that's preventable and can be treated with antibiotics, the U.S. Food and Drug Administration says.

Indigenous kids the biggest winners in new skin sore treatment

October 13, 2014
Medics in remote Aboriginal communities will welcome a new oral treatment for highly contagious skin sores, known as impetigo. The treatment replaces painful penicillin injections for children.

Amateur photographers aid in remote skin sore trial

November 21, 2014
Paediatric infectious disease specialists are bringing novel skin sore research methods to WA in the form of a protocol allowing non-professional photographers to capture high-quality images of skin sores for use in treatment ...

'Drink medicine' works as well as injection to treat skin sores

October 12, 2017
When a child is sick, they are never happy to have a painful needle injection. So being able to take a drink medicine instead is definitely a good thing.

Death rates from rheumatic heart disease falling since 1990

August 23, 2017
The risk of dying from rheumatic heart disease, a condition of damaged heart valves caused by bacterial infection that leads to rheumatic fever, has dropped around the world over the last 25 years, according to a new scientific ...

High rate of strep bacteria bugging kiwi kids

March 19, 2015
More than half of healthy New Zealand pre-school children are carriers of Staphylococcus aureus, and one in six hosts Streptococcus pyogenes in their nostrils, throat or crook of the arm, according to new research from the ...

Recommended for you

Breakthrough in designing a better Salmonella vaccine

September 24, 2018
UC Davis researchers announce in the Proceedings of the National Academy of Sciences this week a breakthrough in understanding which cells afford optimal protection against Salmonella infection—a critical step in developing ...

Antifungal agent found to be possible treatment for porphyria

September 24, 2018
A large team of researchers from Spain, France and the U.S. has found that a common antifungal agent might be useful as a treatment for a rare type of porphyria. In their paper published in the journal Science Translational ...

New findings on the muscle disease Laing early-onset distal myopathy

September 24, 2018
New avenues are now being opened toward treatment of Laing distal myopathy, a rare disorder that causes atrophy of the muscles in the feet, hands and elsewhere. In a study published in the journal PNAS, researchers have identified ...

Insulin shows great potential against chronic colitis

September 24, 2018
Diabetes is not the only disease on which insulin has an effect, it appears. In a new study using tests on mice, researchers from the University of Copenhagen, among others, have discovered a new method for treating chronic ...

A new approach to developing a vaccine against vivax malaria

September 21, 2018
A novel study reports an innovative approach for developing a vaccine against Plasmodium vivax, the most prevalent human malaria parasite outside sub-Saharan Africa. The study led by Hernando A. del Portillo and Carmen Fernandez-Becerra, ...

Pre-clinical success for a universal flu vaccine offers hope for third generation approach

September 21, 2018
Researchers from the University of Oxford's Department of Zoology have demonstrated pre-clinical success for a universal flu vaccine in a new paper published in Nature Communications.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.