When a wound does not heal by itself, it is due to an infection. The severity of the infection depends, among other things, on the type of infection and on how old the wound is, i.e. how much the infection has been able to spread and invade surrounding tissues and structures.
Infections on the outside of the body, e.g. in wounds, are fundamentally different from infections within the body, where complete sterility must be kept. The definition of an infection within the body is, as it always has been, the presence of microorganisms. The conditions on the outside of the body, however, are quite different.
We are surrounded by and in constant contact with microorganisms. They are everywhere in our environment, on every surface we touch, and on us. They live on and in the skin. In fact, we cannot possibly keep our skin healthy without considering and looking after our over 1000 different species of microorganisms that live on us in an ecosystem called the skin microbiome. This microbiological community covers the entire skin surface, which in itself makes it difficult for disease-causing microbes to get a foothold. Our skin microbiome is constantly changing depending on our age, hormone status, food, climate, hygiene etc. and it is in constant communication with our immune system. The immune system, in turn, helps to maintain a good balance in the microbiome by providing a high degree of diversity and avoiding the dominance of one or a few species. Skin and wound infection are defined as an imbalance in the microbiome of such severity that the immune system has lost control of the area with the result that one or a few microbial species have become dominant and taken over control.
|Infection is an unbalance in the microbiome|
|Healing wound||Infected wound|
|Diverse microbiome.||One species has taken over control.|
This relatively new understanding of a wound infection, provides a logical explanation to why the FDA in 2016, following a thorough scientific review of the literature in the field, concluded, that antimicrobials do not work against wound infections. Antimicrobial agents such as antibiotics and antiseptics (e.g. silver, chlorhexidine, PHMB, etc.) kill the microbes without distinguishing which ones are in too high or too low numbers and whether their presence in the microbiome may actually be crucial.
Antimicrobial resistance has become a genuine problem in recent years and it is now known, that bacteria develop resistance to both antibiotics and antiseptics. Antiseptics can create resistance to a different type of antiseptics than the one that caused the resistance as well as to antibiotics (cross-resistance). Resistance development is targeted (not random), quick (few hours or days) and it is permanent (does not change back). In addition, the change is associated with a more aggressive behaviour (virulence) in the bacteria. This knowledge has only been established within the last few years and, in practical terms, it means that the problem of antibiotic resistance is not limited to the fact that our antibiotics do not work, but also that using antimicrobials in the wrong places, such as for example in wounds, accelerates the development and spread of resistance.
Today, as we can all be expected to carry at least one resistant bacterium in our skin microbiome, the use of antimicrobial agents will not eradicate all the microbes in the wound. The resistant type will not be affected but will remain in the wound, whereas the non-resistant types will be killed. Put into practice, this means that the treatment specifically favours and selects for the resistant bacterial type providing it with ideal conditions to multiply, occupy and control / infect the entire wound. The result is a wound full of resistant, highly aggressive bacteria. The use of antiseptics in wounds can therefore no longer simply be regarded as something that does not work. On the contrary, it poses a danger as it aggravates the wounds and reinforces and spreads resistance to the patient and to those with whom the patient comes into contact.
|Infected wound with resistant bacteria||After treatment with antimicrobials||Infection is more dangerous|
One species dominating
|Resistant strains survive and become more aggressive||Worsening of the infection|
|Washing or dressing wounds with products that kill bacteria makes the infection worse and more dangerous.|