Overview

What is impetigo?

Impetigo is a highly contagious bacterial infection that affects the skin. Although impetigo can affect anyone at any age, impetigo typically affects children between 2 and 5 years of age. Most cases of impetigo are mild and can be easily treated with antibiotics. Continue reading to learn about what causes impetigo, how to treat impetigo and how to prevent impetigo from spreading.^1,2,3

What are the symptoms of impetigo?

There are two types of impetigo – bullous and non-bullous.

• Non-bullous impetigo is the more common form of impetigo, accounting for 70% of cases. This form is usually milder and tends to involve the face (particularly around the nose and mouth), limbs and joints (especially the armpit). Non-bullous impetigo begins as clusters of thin-walled pustules. These quickly rupture and form characteristic golden brown crusts^1,3
• Bullous impetigo presents as large, fluid-filled blisters that are around 1cm in size. These blisters are fragile, rupturing easily and leaking yellow liquid. After rupturing, scaley circular rims may be left on the skin^1,2

Impetigo can be itchy and painful. Although impetigo is an infection that affects the skin, sometimes the effects can extend to the whole body, resulting in fever and swelling of lymph nodes.¹

What are the causes of impetigo?

Impetigo is a skin infection that is caused by bacteria. The blisters in impetigo are caused by a skin reaction to toxins that are produced by the bacteria.³

Non-bullous impetigo can be caused by either Staphylococcus aureus or Streptococcus pyogenes. On the other hand, bullous impetigo is almost always caused by Staphylococcus aureus.¹

Impetigo can also be caused as a secondary infection, where the skin is damaged and offers an opportunity for the bacteria to invade and cause infection. This means that there is a chance of developing impetigo after a cut or burn that leads to breaks in the skin. There is a higher risk of impetigo in people with skin conditions including eczema, insect bites, scabies and chickenpox.^3,4

Warm, humid weather, poor hygiene and crowded environments all make it easier for impetigo to spread in a population. Impetigo can be spread through:²

• Direct transmission including close contact with infected individuals
• Indirect transmission through sharing contaminated objects with infected individuals, including toys, clothing and towels

When should I see a doctor about impetigo?

With non-bullous impetigo, it is possible to wait for it to resolve on its own without treatment if it is mild and the chance of complications is low. Impetigo tends to be mild if there is no fever, and the impetigo is limited to a small area. Medical advice should be sought if the infected individual is very unwell, has widespread impetigo, or has bullous impetigo.⁴

Without treatment, impetigo can take one to three weeks to resolve. Treatment is useful for limiting the spread of infection and reducing the time it takes to heal down to one to two weeks.⁴

It is important to be cautious and seek medical advice when impetigo affects newborn babies and individuals with a compromised immune system. These groups are more vulnerable to developing complications, including severe skin infections (such as cellulitis, ecthyma, Staphylococcal scalded skin syndrome), lymphangitis and sepsis.³

What are the treatments for impetigo?

As a bacterial infection, impetigo can be treated with antibacterials and antibiotics. Antibiotics work by targeting the bacteria and stopping the infection. In the UK, these treatments require a prescription from a prescriber. With any treatment, always check the directions on how to use the treatment and follow the advice of the doctor or pharmacist.

Topical treatments

Topical treatments include creams, ointments and gels that can be applied to the skin. These treatments are highly effective for impetigo because they can deliver a high dose of drug directly to the skin infection.¹

Topical treatments are also easier to use. Oral medicines that are swallowed can cause side effects such as an upset stomach, nausea or vomiting. Although the side effects are mild, some children find oral medicines to be unpleasant. The side effects of a topical treatment are usually limited to the skin. For example, it can be common to experience mild skin irritation, due to the ingredients that are included in creams and ointments.

It is advisable to always wash hands after using a topical treatment unless the cream is being used to treat the hands. This will prevent the cream from irritating healthy skin. Unless otherwise specified, care should be taken to avoid using topical treatments near the eyes.²

Hydrogen peroxide has antimicrobial effects and is usually the first-line treatment for mild cases of impetigo. In the UK, hydrogen peroxide 1% cream is the only impetigo treatment that can be bought over the counter in pharmacies. The cream is a potent medicine that is licensed for the treatment of surface skin infections. The cream is normally applied two to three times daily to the affected areas for five to seven days.²

Fucidic acid and mupirocin are topical antibiotics that work against staphylococcal infections. In impetigo, they are applied three times daily for five to seven days.^1,4

Oral antibiotic treatments

If the impetigo is widespread, or if the individual is at higher risk of complications, then oral antibiotic treatment may be a better choice to fight the infection.¹

Oral antibiotic treatments come in a variety of forms that can be swallowed, including tablets, capsules and liquids. Liquid formulations such as oral suspensions and solutions are a helpful alternative for young children who find it difficult to swallow tablets and capsules. Liquid formulations tend not to keep for long. Some may only last for a few days before needing to be discarded. Some liquid preparations need to be kept in the fridge so that they may continue to work properly. A pharmacy can provide special spoons or syringes that can be used to measure the correct dose.

The antibiotic flucloxacillin is normally chosen as the first-line treatment for skin infections. In impetigo, the recommended treatment course doses flucloxacillin four times a day for five to seven days. Flucloxacillin should be taken on an empty stomach. This means that the medicine should be taken at least one hour before or two hours after a meal. Flucloxacillin is a penicillin-type antibiotic.^1,4

For people with allergies to penicillin, clarithromycin or erythromycin may be prescribed as an alternative. These are both macrolide antibiotics, which are a different class of antibiotic from penicillin. Like flucloxacillin, erythromycin is normally taken four times daily whereas clarithromycin is taken twice daily.⁴

Antibiotic resistance

Overuse and misuse of antibiotics in recent years have led to the emergence of bacteria that are resistant to antibiotics. This means that our antibiotic treatments are becoming less effective against bacterial infections. This makes it difficult to treat infections.

Although rare, there is a growing concern for impetigo caused by infection with Meticillin-resistant Staphylococcus aureus (MRSA). MRSA is a highly resistant bacteria that is resistant to the usual arsenal of antibiotics that are used for skin infections. This makes it difficult to treat MRSA.¹

To reduce the rise of antibiotic resistance, it is important to use antibiotics responsibly and to follow the advice of your medical practitioner. This includes:

• Follow the instructions on how to use antibiotics and how often
• Finish the full course of antibiotics
• Avoid sharing antibiotics with other people

How can impetigo be prevented?

Since impetigo is due to bacterial infection, good hygiene measures can be used to prevent the spread of impetigo to other body areas and other people. For example:⁴

• Avoid close contact with infected individuals, or sharing towels
• Wash afflicted areas with soap and water
• Avoid touching or scratching patches of impetigo
• Wash hands regularly, including after touching affected areas
• Cover affected areas where possible
• Clean equipment (including toys and play equipment) daily

Summary

Impetigo is a contagious infection that is most common in young children. Of the two types of impetigo, it is the milder form – non-bullous impetigo – that is more common. Impetigo is caused by bacteria and can be treated with antibiotic treatments that are applied directly to the skin or swallowed. To prevent spreading impetigo to other people, it is important to maintain good hygiene when managing the condition.