Treatment of impetigo: Topical ointment, systemic drugs and antibiotics

Local treatment

In both types of impetigo, ointments (3-5% salicylic petroleum jelly) are used to soften the scabs. In addition, moist bandages with disinfectant solutions are recommended.

The patient with impetigo should follow certain precautions. Instead of bathing, he should take a short shower. He should use disinfectant soap for washing.

The doctor must take an individual approach to the choice of medication. The likelihood of contact allergy and the possibility of resistance must be considered. Good cooperation on the part of the patient is an important condition for topical treatment.

The following drugs are used for the topical treatment of impetigo:

• bacitracin
• neomycin
• fusidic acid
• mupirocin

The combination of neomycin and bacitracin is one of the commonly used drugs in practice. However, this combination is not suitable for the treatment of impetigo.

Neomycin is particularly suitable for eradication of aerobic Gram-negative bacteria. The effect of neomycin on Gram-positive bacteria is largely limited.

Currently, mupirocin or fusidic acid is mainly used for the topical treatment of impetigo.

• Mupirocin

Mupirocin is mainly used for the topical treatment of primary and secondary bacterial skin infections. Its other uses include:

1. preventing bacterial contamination of small wounds
2. prevention of infection of abrasions and small cuts and wounds

• Fusidic acid

Fusidic acid is mainly used to treat primary bacterial skin infections (impetigo, furuncle). It is also used in the case of infected skin wounds or secondary infected dermatoses (atopic and contact dermatitis).

Fusidic acid is effective against a number of Gram-positive bacteria and some Gram-negative cocci. For example, Staphylococcus aureus and Corynebacterium sp. are very sensitive. Streptococci are moderately sensitive.

Drugs for topical use containing fusidic acid are available in cream and ointment form. Compared with other topical antibiotics, it shows similar efficacy and comparable or better tolerability.

Fusidic acid, like mupirocin, is more effective than oral antibiotics in the treatment of some types of impetigo.

Systemic treatment

Systemic antibiotic treatment is chosen by the doctor in case of failure of local treatment of impetigo or in case of more extensive manifestations. In case of complicated and generalised manifestations, systemic antibiotic treatment prevents the development of complications (glomerulonephritis).

Systemic treatment is appropriate for patients:

• whose condition does not improve with local treatment
• with large and multiple foci
• with compromised immunity
• suffering from severe disease

In the case of staphylococcal infections, the following are used in practice:

• Oxacillin

Oxacillin belongs to the group of oxazolylpenicillins. They are resistant to β-lactamases produced by staphylococci. Therefore, they are also referred to as antistaphylococcal antibiotics.

The use of oxacillin is indicated in patients suffering from infection caused by strains of Staphylococcus aureus with microbiologically confirmed susceptibility.

• Amoxicillin/clavulanic acid

Amoxicillin belongs to the aminopenicillin group. Staphylococci that produce β-lactamase are resistant to its action.

However, by the appropriate addition of clavulanic acid (a β-lactamase inhibitor), the spectrum can be significantly broadened and this principle is often used therapeutically.

• Cephalexin

Cephalexin is classified as a first generation cephalosporin. Its mechanism of action is based on the killing of susceptible micro-organisms at the time of reproduction. It has a broad spectrum action (against many micro-organisms).

For streptococcal infections, the doctor usually prescribes:

• Phenoxymethylpenicillin potassium salt

Phenoxymethylpenicillin is a biosynthetically modified basic penicillin. It is mainly used in the treatment of mild to moderate infections.

Its advantageous properties include resistance to the acidic environment in the stomach. For this reason, it can also be administered orally.

The spectrum of antibacterial activity of phenoxymethylpenicillin corresponds to that of penicillin G. This means that it includes pathogens such as Staphylococcus aureus, Streptococcus pyogenes (species A), Streptococcus (species B and C) and anaerobic streptococci.

• Azithromycin

Azithromycin is a second-generation macrolide antibiotic. It is used in the treatment of infections caused by Gram-positive bacteria.

Its advantageous properties include excellent tissue penetration, improved tolerance and an extended spectrum of activity. A major advantage is its long biological half-life, which allows dosing every 24 hours.

What are the new treatment options for impetigo?

We are currently facing the threat of increasing antibiotic resistance. Therefore, scientists are looking for new therapeutic approaches. Alternative treatments are divided into two groups:

1. Chemical

This treatment method uses organic substances, which include the antibiotics mentioned above. In addition to organic substances, this group includes metal nanoparticles, substances that cause photo-oxidative stress reactions and the accumulation of oxygen radicals.

These substances are disadvantageous for use in dermatology because they can prolong wound healing.

2. Biological

The advantage of biological therapy is that it does not damage the skin microbiome and is selective. Biological therapy includes phage therapy, antimicrobial peptides and enzyme therapy.

Have you heard of enzybiotics?

Enzybiotics represent a new way of treating skin and soft tissue infections. Lytic enzymes are used in the treatment. They hydrolytically cleave the covalent bonds in the peptidoglycan of the cell wall. The result is cell breakdown.

Peptidoglycan makes up 30 to 70 % of the cell wall of Gram-positive bacteria.

According to the site of cleavage of the bond in the peptidoglycan, enzybiotics are divided into:

• muramidases
• glucosaminidases
• amidases
• endopeptidases

Due to their unique mechanism of action, these enzymes act even on bacteria that are resistant to all major antibiotic groups.

One of the best studied enzybiotics is lysozyme, which generally has antimicrobial effects against Gram-positive bacteria such as Staphylococcus aureus.

Another well-known enzyme is lysostaphin, which has effects against most strains of Staphylococcus aureus.