Introduction

You took your child to the doctor and were told he had a skin infection. You hear the word impetigo and immediately feel a sense of fear. The fear, that comes from not knowing what it means, whether it is serious or not. Impetigo is a bacterial skin infection in which honey-coloured or yellow crusts tend to form over red, oozing sores.^1,2

In this article, we provide you with the necessary information to understand important aspects of impetigo, specifically the bacteria involved. Other articles here on Klarity will give you more detailed information about what this disease is.

The focus of this article is to explain the bacteria that cause impetigo. So that you can better understand how a person can become infected with impetigo, how to avoid it, and also how the treatment works. Let us always remember that prevention is the best medicine.

Overview of bacteria involved

Main bacterial causes

Impetigo is caused by bacteria, it’s necessary to remember that a bacterium is a microscopic organism which is composed of only one cell but no nucleus, instead, its genetic material is floating in the cytoplasm. But besides that, it can perform the seven processes that characterise life, these are movement, respiration, sensitivity, growth, reproduction, excretion and nutrition.³

The two main causes of impetigo are:

1. Staphylococcus aureus
2. Streptococcus pyogenes⁴

Staphylococcus aureus

Characteristics

Since bacteria are microorganisms, it is necessary to stain them to identify well in the microscope. A specific staining technique, Gram staining, makes some bacteria look purple-brown (Gram-positive) and others red (Gram-negative).⁵

In the case of Staphylococcus aureus, it’s a Gram-positive bacterium, and the common habitats are skin and nose.

Role in impetigo

Since Staphylococcus aureus generally lives on our skin and nose, it tends to take advantage when there is a skin injury. Examples of these injuries include scratches, abrasions, and cuts. When it enters our skin, it also produces toxic substances that tend to separate the cells that make up the skin. It can also cause blisters, leading to bullous impetigo. 30% of impetigo cases are bullous, and 70% are non-bullous. Staphylococcus aureus can cause both types.⁶

Streptococcus pyogenes

Characteristics

The Streptococcus pyogenes, also known as group A beta-haemolytic streptococci (GABHS), is a Gram-positive bacterium too. It causes nonbullous impetigo. This enters the skin after a trauma.⁷

Role in Impetigo

This bacterium colonises the skin, taking advantage of any minor lesion. Then it produces substances that facilitate the invasion of tissues, for example, the hyaluronidase that breaks down hyaluronic acid in the skin and streptolysins for damaging the host cells. This avoids the immune system so the infection can be established.⁸

Staphylococcus pyogenes gets into the epidermis, causing the separation of skin layers and consequently, there is a formation of red, inflamed lesions showing characteristic honey-coloured crusts.⁸

Transmission of Impetigo

The principal way of impetigo’s transmission is through direct contact from skin to skin. It is highly contagious when people come in contact with the lesions or the content of the blisters or crusts of someone already infected.^4,9

Another way of getting infected is by having contact with broken skin with a surface on which bacteria survive. For instance, towels, clothing, or other non-animated objects. We should also take into account that scratching an impetigo lesion and touching other parts of the body can spread the infection to those areas.^4,9

Common environments for transmission

Schools and daycare centres

Schools and daycare centres tend to be environments where the transmission of impetigo occurs, as it is more common in children, and they may have certain limitations in practising optimal hygiene routines.

Sports activities

Sports activities, especially those involving a lot of contact like wrestling and shared equipment, can increase the chances of transmission if someone is infected.

Household settings

Household settings fall into that group of places where transmission commonly occurs because many items tend to be shared. If factors such as overcrowding or conditions of high humidity and warmth are added to the scenario, transmission is more likely to occur.⁴

Prevention strategies

After what has been read before, we can understand that preventing impetigo requires various strategies, such as:

Personal hygiene

Regular handwashing

Wash your hands with water and soap regularly, especially after touching surfaces that potentially could be contaminated. Also, teach children the importance of washing their hands.

Avoiding sharing personal items

Word personal is given for a reason, so It must always be a priority to not share personal items. However, if it is required to be shared, clean/sanitise the shared items.

Managing skin Injuries properly

• First aid for cuts and scrapes
• Seeking prompt medical advice for skin infections
• Avoid scratching the impetigo’s lesions for not spreading the infection

Environmental cleanliness

1. Disinfecting surfaces
2. Washing clothing and bedding

FAQs

What is impetigo?

Impetigo is a bacterial skin infection characterised by honey-coloured or yellow crusts forming over red, oozing sores.

What causes impetigo?

Impetigo is primarily caused by two bacteria: Staphylococcus aureus and Streptococcus pyogenes.

How does Staphylococcus aureus contribute to impetigo?

Staphylococcus aureus, a Gram-positive bacterium, typically inhabits the skin and nasal passages. It exploits skin injuries to infiltrate and produce toxins, leading to impetigo lesions.

What role does Streptococcus pyogenes play in impetigo?

Streptococcus pyogenes, also a Gram-positive bacterium, colonises the skin and produces substances that facilitate tissue invasion. It leads to impetigo lesions by causing the separation of skin layers.

How is impetigo transmitted?

Impetigo is highly contagious and spreads through direct contact with infected lesions or contaminated surfaces. It can also occur through contact with broken skin or shared items.

What are common environments for impetigo transmission?

Impetigo transmission is common in settings like schools, sports facilities, and households, where contact and shared items facilitate bacterial spread.

What are some prevention strategies for impetigo?

Preventing impetigo involves practising personal hygiene, such as regular handwashing, avoiding sharing personal items, maintaining environmental cleanliness by disinfecting surfaces; washing clothing and bedding; and managing skin injuries properly.

Why is impetigo prevalent in schools and daycare centres?

Impetigo is prevalent in schools and daycare centres due to the close contact among children and potential limitations in maintaining optimal hygiene practices.

How can impetigo be avoided during sports activities?

During sports activities, impetigo can be avoided by practising good hygiene, avoiding sharing equipment, and promptly addressing skin injuries.

Why is prompt medical advice important for impetigo?

Seeking prompt medical advice for impetigo is crucial to prevent complications and ensure appropriate treatment, especially in severe or recurrent infections.

Summary

To fully comprehend impetigo and effectively combat it, it's crucial to delve into the bacteria responsible for this infection. Staphylococcus aureus and Streptococcus pyogenes take centre stage, exploiting even the slightest skin injuries to wreak havoc. Staphylococcus aureus, typically found on the skin and in nasal passages, capitalises on wounds to infiltrate and produce toxins. 

Meanwhile, Streptococcus pyogenes thrives by breaking down skin tissues. These bacteria collaborate in creating the telltale impetigo lesions, spreading the infection through direct contact or contaminated surfaces. Common environments for transmission include schools, sports facilities, and households. 

Prevention strategies encompass personal hygiene, environmental cleanliness, and proper management of skin injuries. By embracing these measures, we can effectively curb impetigo's spread and prevent its recurrence, underlining the significance of proactive healthcare practices in maintaining overall well-being.