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How do you recognize a wound infection?

by Josephine Andrews
Published: Last Updated on 364 views

If a wound is red, painful, and swollen, this indicates a wound infection. It develops when pathogens (usually bacteria) invade and inflame the wound. Wound infections usually occur after injuries or operations. Treatment options include sterile wound dressings, germ-killing ointments and antibiotics. How to recognize inflamed wounds and what helps against them, read here!

ICD codes for this disease:

ICD codes are internationally valid codes for medical diagnoses. They can be found, for example, in doctor’s letters or on certificates of incapacity for work.


quick overview

  • Symptoms: Inflamed wounds are red, swollen and painful. In addition, they are often purulent and smell bad. In severe cases, the surrounding tissue dies off or blood poisoning occurs, which manifests itself in the form of fever, chills and a rapid pulse, among other things.
  • Treatment: cleaning the wound, rinsing with disinfectant solutions, daily change of bandages; in advanced wound infection with antibiotics. In severe cases, an operation (eg removal of dead tissue) is necessary.
  • Description: Wound infection is inflammation of a wound caused by pathogens (usually bacteria).
  • Causes: Microorganisms such as bacteria, more rarely viruses , fungi and parasites penetrate the wound, causing it to become inflamed.
  • Diagnosis: Discussion with the doctor, physical examinations (eg assessment of the wound, blood test, taking tissue samples)
  • Course: As a rule, a wound infection is easy to control if it is treated carefully and at an early stage. In the case of advanced and untreated wound infections, serious complications such as blood poisoning can sometimes occur.
  • Prevention: Pay attention to sufficient hygiene, clean wounds carefully and keep them clean, change bandages regularly

How do you recognize a wound infection?

Those affected recognize a wound infection by the fact that the wound heals only very slowly (wound healing disorder). The infected wound is usually red and swollen. It hurts and is warmer than the surrounding non-inflamed tissue. Possibly, pus will come out of the wound. If the infection is already more advanced, those affected are often affected by fever, chills and nausea.

In severe cases, blood poisoning (sepsis) occurs, in which the immune system not only attacks the pathogens. The body is also badly affected – up to the failure of one or more organs. In rare cases, it is also possible for the pathogens to get into the bones directly from the inflamed wound or via the blood and inflame them (osteomyelitis).

Signs of infection directly in the wound area are:

  • The wound is red.
  • She’s swollen.
  • The affected area of ​​skin feels warmer (overheating).
  • The infected wound is painful and tender to the touch.
  • The surrounding tissue is hardened.
  • Pus comes out of the wound.
  • Increased wound secretion escapes from the wound (“weeping wound”).
  • Sensations are in the inflamed wound area

Other signs that indicate an advanced or severe infection and blood poisoning (sepsis) are:

  • Affected people get fever and chills.
  • They feel nauseous and have to vomit.
  • The wound heals very slowly.
  • The wound smells bad or foul (putrid smell).
  • Pockets and cavities form at the bottom of the wound.
  • Abscesses (cavities filled with pus) develop.
  • The wound changes color (eg a greenish color indicates a Pseudomonas infection).
  • The pain gets worse.
  • The function of the affected limb is restricted.
  • The heart rate is increased.
  • Breathing accelerates .

What can you do with an infected wound?

wound care

To treat a wound infection, the doctor first cleans the wound thoroughly with saline solution. He then rinses the wound with an antiseptic solution to disinfect it. In the case of severe inflammation, for example when tissue has already died, he may remove the infected, damaged or already dead tissue (debridement).

In the case of heavily weeping wounds, the doctor also carries out wound drainage. He drains the wound fluid to the outside with the help of a plastic tube that he inserts into the wound.

The doctor then bandages the wound with sterile bandages (eg wound dressings , gauze bandages, compresses). This should be changed daily if possible.

With every wound it is important to keep it clean and protected from contamination!


If the wound has become infected with bacteria and the infection has progressed further, simple wound care is no longer sufficient. The doctor then usually prescribes a suitable antibiotic, usually in tablet form. In the case of infections with aggressive germs (eg with certain hospital germs), those affected receive antibiotics by means of an infusion directly into the bloodstream

If the wound infection penetrates into deeper tissue layers, becomes inflamed over a large area, or there is a risk of blood poisoning, the doctor immediately administers antibiotics. Targeted therapy with antibiotics is essential here in order to prevent serious, sometimes life-threatening complications (eg organ failure).

In most cases, those affected are already given a broadly effective antibiotic before the doctor receives the analysis of the triggering type of bacteria from the laboratory. This reduces the risk of complications and severe courses. If the laboratory result is available, it is sometimes necessary to change the antibiotic in order to fight the pathogen even more specifically.

During operations, the doctor often prescribes antibiotics to prevent infections before, during or after an operation.

If you are allergic to a certain antibiotic, be sure to tell your doctor!

Passive tetanus vaccination

If there is a suspicion that a tetanus infection (lockjaw) is present, the doctor administers so-called tetanus immunoglobulin in addition to antibiotics. These are tetanus antibodies that intercept the toxin of the causative bacterium Clostridium tetani. The doctor calls this passive immunization against tetanus. This is particularly necessary when it is not clear whether the person concerned has adequate vaccination protection. In addition, those affected often have to be treated in intensive care because a tetanus infection is potentially life-threatening.

home remedies

Some home remedies should also help to support wound healing. For example, ointments are made from echinacea, chamomile, St. John’s wort oil or calendula, which are applied thinly to the edges of the wound, are said to have positive effects on the healing process.

Cod liver oil can be used on burns to reduce scarring. However, wound care and healing should always be accompanied by a doctor.

Cooling compresses, compresses or cooling pads can also help against inflamed and especially overheated wounds. It is important to ensure that the skin is not damaged by the cold. In addition, only clean, ideally sterile materials (eg cloths) should be used as wound dressings.

Other herbal remedies for infected wounds include: balloon vine herb, propolis, sage , hops , arnica, and horsetail.

Home remedies have their limits. If the symptoms persist over a longer period of time, do not get better or even get worse, you should always consult a doctor.

What is wound infection?

In the case of a wound infection, pathogens (eg bacteria) penetrate the wound and cause inflammation there. It usually occurs after injuries, bites or surgeries. Wound infections are the most common cause of impaired wound healing. In severe cases, a severely inflamed wound develops into life-threatening blood poisoning.

What triggers a wound infection?

The most common cause of wound infection is bacterial invasion of a wound. This causes inflammation. In addition, viruses, fungi or parasites trigger a wound infection in a few cases. The pathogens are usually transmitted by contact or smear infection (eg when the wound comes into contact with dirty surfaces such as door handles, computer keyboards or toilet seats).

contact wounds

If the wound was created under unhygienic conditions, for example as a result of an injury with contaminated splinters of wood, wound infection is particularly common.

If contaminated water gets into open wounds, this also promotes wound infections by bacteria such as the bacterium Vibrio vulnificus. It occurs, for example, in estuaries or in brackish water and triggers rapid skin inflammation that can lead to blood poisoning.

Dead tissue, accumulations of older blood or tissue fluid and foreign bodies in the wound encourage microorganisms to multiply and thus lead to infections.

wounds after operations

Infection of wounds also occurs after surgery (postoperative or surgical wound infection). Postoperative wound infections typically occur a few days after surgery, but can occur several weeks after surgery.

In this case, the wound itself and the skin sutures may become inflamed (eg after a wisdom tooth operation). Local wound infections often occur at the exit point of the tube in the abdominal wall during long-term feeding of seriously ill people or people in need of care via a tube (percutaneous endoscopic gastrostomy, or PEG for short). Even after stitches are removed from stitched wounds, there is a risk of infection with pathogens.

Infections after operations are sometimes serious, as they are often caused by hospital germs that are insensitive (resistant) to certain antibiotics (eg methicillin-resistant Staphylococcus aureus, or MRSA for short). They therefore do not respond, or hardly at all, to treatment with certain antibiotics.

Bite wounds and burns

Germs can also easily get into the wound through animal bites or large-area burns and trigger inflammation. The germs in the saliva of animals promote infections. In the worst case, they lead to a life-threatening tetanus or rabies infection if the animals are infected with the corresponding germs. Since these wounds often heal more slowly, it is also easier for other microorganisms to enter the wound.

If it’s been more than ten years since you had your tetanus vaccination, you should get a booster quickly!

How does a wound infection come about?

On the one hand, whether a wound infection occurs depends on the type and number of germs in the wound. On the other hand, the general condition of the person concerned plays a role. Not every wound contaminated by germs necessarily becomes inflamed. Only when the number of potentially pathogenic germs is high and the body’s own defense system is weakened does the wound become inflamed.

A distinction is made between the following types of wound infections caused by bacteria:

pyogenic wound infection

Pyogenic wound infection is often caused by cocci, a group of spherical bacteria (certain species of staphylococci and streptococci). Often pus forms in the wound. Other pathogens for pyogenic wound infections are Pseudomonas aeruginosa, Escherichia coli, enterococci, Proteus and Klebsiella.

Putrid wound infection

The reason is usually an infection mixed with various pathogens (e.g. Clostridia, Proteus vulgaris, Streptococcus anaerobius, Streptococcus putridus), which form with or without oxygen (aerobic and anaerobic bacteria). These decompose tissue surfaces (necrosis) and form foul-smelling gases (putrefaction gases).

Anaerobic wound infection

Anaerobic wound infection is caused by bacteria that (also) develop without oxygen (e.g. Escherichia coli, Bacteroides fragilis, anaerobic cocci, fusobacteria). These usually lead to foul-smelling abscesses that fester profusely. If left untreated, the inflammation will continue to progress.

Bacterial-toxic wound infection

Triggers are mostly anaerobic bacteria such as Clostridium tetani and Clostridium perfringens as well as Corynebacterium diphtheriae. They produce toxins that cause the potentially life-threatening wound infections tetanus/lockjaw (Clostridium tetani) and gas gangrene (Clostridium perfringens) and diphtheria (Corynebacterium diphtheriae).

Specific wound infection

Pathogens for a specific wound infection are so-called atypical mycobacteria such as Mycobacterium fortuitum (after footbaths) as well as Mycobacterium abscessus and Mycobacterium chelonae (eg on contaminated surgical instruments for operations). With a specific wound infection, fistulas often form. It is also typical that the infection occurs again and again (chronic-recurrent). Infection often spreads to lymph nodes and adjacent soft tissues.

How does the doctor make a diagnosis?

If a wound infection is suspected, the general practitioner is the first point of contact. He examines the wound and either treats it himself, refers the affected person to a specialist (eg dermatologist) or arranges direct admission to a hospital (eg if blood poisoning is suspected).

At the beginning of the diagnosis, the doctor first conducts a detailed discussion (anamnesis), which is followed by a physical examination.


Before the actual examination of the wound, the doctor conducts a detailed discussion with the person concerned. Among other things, he asks questions about how the wound came about (eg through a bite, after an operation), what other symptoms the person concerned has (eg fever, severe pain) and how long the wound has existed. Typically, wounds heal more slowly when infected with germs.

Physical examination

The doctor then examines the wound and feels it carefully if necessary. By palpating, he checks whether the underlying tissue is hardened, warmed up or swollen.

If the suspicion of an infection increases, the doctor carries out a blood test to identify the pathogen. This provides him with important information for choosing the right therapy (eg administration of antibiotics for bacteria or which antibiotic against which type of bacteria).

The blood test gives the doctor additional indications of a wound infection through characteristically changed blood values, eg:

  • increase in the number of white blood cells in the blood (leukocytosis)
  • Increase in a non-specific inflammation value (C-reactive protein), which the doctor uses to assess the severity of an infection
  • Increased blood sedimentation rate (abbreviated: ESR, indicates an inflammation)

In addition, the doctor takes a swab from the wound to examine it for bacteria. To do this, he uses a sterile cotton swab to take a swab from the inflamed wound and has the sample examined in a laboratory for infection with pathogens. There it is determined which pathogen it is. At the same time, tests are carried out to determine which antibiotic is effective against the respective bacterium.

In some cases, the doctor uses imaging methods such as an ultrasound examination (sonography), an X-ray examination or a magnetic resonance imaging (MRI) to detect the spread of the inflammation and accumulations of pus.

When to the doctor?

If wounds do not heal by themselves after a few days or if the symptoms even worsen, you should consult a doctor immediately. If you have a fever, chills, nausea or shortness of breath, please do not hesitate to see your family doctor immediately.

Large and deep wounds as well as lacerations or bite wounds from animals should always be examined directly by a doctor. Larger wounds should also be stitched up within the first six hours, as the risk of infection is greatly increased.

Heavily soiled wounds or wounds with stuck foreign bodies should also be treated by a doctor. In people with chronic diseases such as diabetes mellitus, wounds heal more slowly. Here the doctor is all the more challenged when it comes to wound care.

How long does it take for an infected wound to heal?

Depending on the type of pathogen and the wound (e.g. bite, burn, cut) and depending on the state of health of the person affected, wounds become infected within a few hours to a few days.

If the wound is and remains slightly inflamed, the body fights the infection itself. The wound then heals slowly but steadily if the wound is properly cared for. In heavily contaminated wounds that are not adequately cared for, the inflammation may worsen.

If the infection spreads throughout the body and is still not treated, there is a risk, in the worst case, of life-threatening blood poisoning.

As a rule, however, a wound infection can be treated well if it is treated early and regularly. Inflamed wounds usually heal within a few days to a few weeks. Sometimes scars remain.

Wound infections slow down the healing process and trigger life-threatening complications such as blood poisoning. It is therefore important to detect and treat infections early.

How can you prevent a wound infection?

Here’s what you can do yourself to prevent wound infection:

  • Wash or disinfect your hands thoroughly before treating your wound!
  • If the wound is dirty, rinse with cold, running, clean water.
  • Carefully remove small foreign objects such as stones, broken glass or splinters of wood with disinfected tweezers.
  • Then disinfect the wound with an antiseptic solution, antiseptic cream or antiseptic spray.
  • To prevent germs and bacteria from getting into the wound, dress the wound with sterile bandages. Make sure that you do not stick the wound together (eg with plaster).
  • Change the bandage regularly (every one to two days).

Deep, extensive or gaping wounds should always be treated early by a doctor. The same applies to wounds in sensitive areas such as the eyes or ears. Larger wounds should be stitched up within six to eight hours.

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