Introduction

Impetigo and staph infections are infections caused by bacteria and primarily affect the skin. Staph infections are solely caused by Staphylococcus bacteria, whilst impetigo may be caused by either Staphylococcus or Streptococcus bacteria, although infection by Staphylococcus bacteria is more common. Other than skin infections, Staph may also cause other types of infections, such as food poisoning or pneumonia. There is also the possibility of the bacteria spreading from the skin to the blood or other tissues causing more serious infection. Therefore, it is important to recognise these infections and treat them as necessary to prevent any further harm.

What is impetigo?

There are two forms of impetigo, bullous or non-bullous, with non-bullous being the most common form. Impetigo may also be caused by two different types of bacteria. Most commonly, Staphylococcus aureus will be the culprit of the infection, with bullous impetigo being caused almost solely by Staphylococcus aureus. In fewer cases, impetigo caused by Streptococcus pyogenes also occurs. Impetigo is usually spread by direct skin-to-skin contact, as the bacteria usually live on the skin, and by coming into contact with contagious pus. The bacteria can also spread by coming into contact with contaminated objects like towels or surfaces. The bacteria will usually establish an infection by entering a cut. The infection is usually self-limiting but may become more serious if the infection manages to spread

Symptoms of impetigo

Bullous impetigo

For bullous impetigo, it starts with a lesion filled with yellow coloured fluid. This fluid then darkens and may leak pus. If/when the lesion bursts, a scale-like rim will form.1 The lesions will be more likely to form on areas where there is skin-to-skin contact, such as under the arms, in the folds of the breasts, on the trunk, or in the mouth. Bullous impetigo is also likely to be accompanied by a fever. 

Non-bullous impetigo

Non-bullous impetigo is characterised by a yellow crust, which forms upon the rupture of a pustule.¹ These lesions are found most commonly on the face and limbs. The infection is unlikely to also cause a fever. 

Risk factors

Those most at risk of developing impetigo are usually young children between the age of two to five years old. It is very contagious and may easily spread from person to person, so is more likely to occur in crowded households. Those who partake in skin-to-skin contact sports like wrestling are also more likely to catch the infection. Moreover, people with certain health conditions like diabetes, or those who are immunocompromised also have an increased risk of developing impetigo.¹ 

What is a staph infection?

Staph infections are any infection caused by Staphylococcus bacteria. These range from skin infections to infections of the digestive system, bones, lungs, and more. Transmission also depends on the type of infection experienced.

Types of staph infections

Skin infections

Skin infections spread via contact with highly infectious pus or through skin-to-skin contact. It may also be spread by touching contaminated objects and surfaces. The bacteria will usually enter a cut, which will allow the infection to begin. The possible skin infections include:

• Boils and abscesses are one form of skin infection caused by staphylococcal bacteria. It is characterised by a lump, which is most likely filled with pus and feels tender. Boils will be smaller than the abscesses, with abscesses also showing signs of swelling, redness and warmth. An abscess may also be accompanied by other symptoms like a fever or chills
• Folliculitis involves infection of the hair follicles and presents as small bumps that may be red or filled with pus. They look very similar to pimples and may also be quite itchy
• Cellulitis usually involves red and hot skin at first. The area may then swell causing the skin to appear quite tight and may make it difficult to move, for example, close the hands if the infection is present on the hands
• Impetigo 
• Scalded skin syndrome, which is a rarer Staph infection. It is a serious infection where the skin first blisters and then peels all over the body

Food poisoning

If the infection is contracted by ingesting food, it may cause infection of the digestive system. This will present with typical food poisoning symptoms like vomiting or diarrhoea.

Breast infection

Women who are breastfeeding may develop an infection called mastitis, which presents with swelling and abscess formation in the breasts. It may also make the breasts quite tender and painful. The infection is usually transmitted by bacteria from the baby’s mouth entering the breast. 

Serious staph infections

Staph may also cause a range of serious infections affecting different parts of the body. If it spreads to the blood it may cause sepsis, which, if untreated, may lead to death. If the infection spreads to the bones it may cause septic arthritis by causing infection in the joint, or osteomyelitis which involves infection in the bone. If the Staphylococcus bacteria spread to the heart or lungs they may cause endocarditis (infection of the heart inner lining and valves) or pneumonia (fluid or inflammation in the lungs due to infection) respectively. The bacteria may also spread to the brain causing meningitis, which is an inflammation of the brain and spinal cord protective membranes. Toxic shock syndrome may also occur upon the production of toxic shock syndrome toxin 1 by the bacteria, and tends to be of quick onset and life-threatening. 

Risk factors

Risk factors for getting a staph infection include wearing a tampon for a prolonged period of time as it increases the chance of developing toxic shock syndrome. Breastfeeding also puts women at a higher risk of developing mastitis. Staph infections are also more likely to occur in people with chronic conditions like diabetes or eczema, as well as those who are immunocompromised. People staying or working in a hospital are also more likely to catch a staph infection due to higher prevalence of the bacteria within hospitals, and so higher risk of the bacteria getting onto the skin or food. Those who recently underwent surgery are also more likely to catch the infection.² 

Prevention of impetigo and staph infection

General hygiene practices

To prevent developing both a staph skin infection or impetigo, it is important to have good personal hygiene. This includes practices such as regularly washing the hands and showering, and if there are any visible cuts, they should be kept clean. Personal items like towels should be washed regularly and used only by one individual, not shared between multiple people. For food hygiene, it is important to try to prevent cross-contamination by keeping raw meat away from cooked meats and any other ingredients. It is also key to cook the meat thoroughly and make sure to not leave the food outside of refrigeration for any longer than two hours. It is also important not to eat any food that looks or smells unusual. In terms of using tampons, women should aim not to use the same tampon for any longer than four to eight hours. For women breast feeding and so at higher risk of mastitis, a good preventative measure would be to attempt to fully empty the breast after feeding and allowing the nipple to dry via air drying rather than using, for example, a towel. 

Preventing spread in high-risk settings

High-risk areas like hospitals, leisure centres, or schools should try to minimise the risk of infection transmission by regularly cleaning the settings and any related equipment with antibacterial sprays. 

Treatment options for impetigo and staph infection

Since impetigo may be caused by two types of bacteria and staph infections are caused by Staphylococcal bacteria, the main treatment is antibiotics. The antibiotics may be given orally as a pill or as a topical gel. The type of antibiotic depends on the strain causing the infection and the administration. The main antibiotic used for staph infection is penicillin unless the infection is caused by methicillin-resistant Staphylococcus aureus in which case vancomycin or doxycycline will be used. For nonbullous impetigo, topical treatment is preferred and involves the removal of the crust with soap and water before applying the topical cream.^1,2

Summary

Impetigo is a bacterial skin infection which may be caused by Staphylococcus or Streptococcus whilst staph infections are solely caused by Staphylococcus and may cause other types of infections rather than just skin. However, there is a possibility of impetigo developing into a more serious condition if the infection manages to spread. The most common treatment for both are antibiotics, administered either as a pill or cream. To prevent this infection, people are encouraged to keep good hygiene practices and higher-risk settings are encouraged to maintain good maintenance standards.