Inflamed insect bite

When is that dangerous?

An insect bite is particularly common in the warm months. While most insect bites represent a mundane event, an insect bite can also be associated with acute complications or complications that occur after a certain period of time. While elsewhere a dreaded consequence of an insect bite is the transmission of diseases such as malaria, fortunately these diseases hardly play a role in our latitudes. For us, the complications of the insect bite are on the one hand the allergic reaction and on the other hand the inflammation.

Symptoms of an allergy can occur especially with bee and wasp stings. In severe allergic reactions, which fortunately are rare, the insect bite can affect the circulatory functions, leading to life-threatening complications. Such an acute situation requires an emergency doctor to be called immediately.

Fortunately, in most cases the local reaction after an insect bite is limited to the area of ​​the sting; of inflammation.

Inflammatory reactions are the body's response to external stimuli and serve to ward off these damaging stimuli. The local, i.e. locally limited, inflammation is therefore to be regarded as a normal and sensible reaction to an insect bite. It serves to ward off pathogens and exogenous proteins such as those contained in insect venom or insect saliva. Furthermore, the healing of the wound is promoted by the inflammation.

Problems can cause inflammation after an insect bite, especially if they are caused by colonization of the tissue by bacteria.

Read more about this under Allergy to bee / wasp venom.


Depending on the type of stinging insect, there is no (or only slight) to severe stinging or burning pain during the sting. In addition to pain, signs of inflammation include reddening, swelling (for example in the form of blisters or wheals) and warming of the puncture site and the surrounding tissue.

These symptoms are generally found in all types of inflammation in the body.

Itching can also occur with insect bites. This is precisely what is often perceived as the most bothersome symptom after an insect bite.

The inflammatory reaction can vary significantly depending on the type of insect, personal willingness to react and previous bites. Thus, the symptoms range from punctiform, itchy redness to several centimeters of swelling.

Usually these symptoms are harmless and will subside on their own after a short time. Inflammation from an insect bite can be dangerous if the area around the insect bite is infected by bacteria. If there is extensive redness and swelling that increases over days, often with a feeling of tension or pronounced pain, a doctor should be consulted in order to rule out a bacterial infection of the tissue around the puncture. Pus is also an indication of a bacterial infection and should be evaluated by a doctor urgently. Also pronounced yellowish encrustations, which can arise especially after strong scratching.

Not only the skin and subcutaneous tissue can be infected by bacteria after an insect bite. A sting in the limb can also lead to inflammation of the lymphatic system. This phenomenon, which is often misinterpreted as "blood poisoning" in the vernacular, often results in visible reddening and swelling of the lymph vessels in the arms or legs, also requires medical treatment.

Even after tick bites (which, strictly speaking, do not count as insect bites, since ticks are arachnids), the observation of the puncture site should be of particular importance. Warning symptom for tick-borne borreliosis is the so-called wandering redness (Erythema migrans). Typically there is reddening at the puncture site. This spreads in the course of time in a circular manner, it “migrates”, that is to say, wandering. The name of this phenomenon is derived from this fact.

However, since such a characteristic appearance is not always clearly evident, if in doubt, if there is unclear reddening after a tick bite or unclear bite, a doctor should be consulted. This can, among other things, also perform a borreliosis test. Because erythema migrans can sometimes quickly regress, it can make sense to photograph the visible inflammation of the mosquito bite and present the images to the treating doctor later.

You might also be interested in this topic: Lymph node swelling after an insect bite

Purulent, inflamed insect bite

Pus is an indication of an inflammatory reaction in the body. It is a yellowish liquid, which usually consists of defense cells of the body and other dead body cells and bacteria. In most cases, pus develops when there is a bacterial infection (superinfection). This can easily happen with an infected insect bite, as the pathogens get into the wound under the skin by scratching the bite. In the case of suppurative inflammation due to an insect bite, a doctor should always be consulted. Since bacteria are responsible for the development of pus, antibiotic therapy should be initiated. The pus should also be removed mechanically. In the case of very large pus cavities, this procedure is carried out in a hospital in surgery. Small abscesses, however, can be removed by a general practitioner himself. After starting antibiotic therapy, the bacterial inflammation should decrease significantly after about 48 hours.

Read more about this under Blood poisoning after an insect bite

Insect bite with ring-shaped reddening

In general, various insect bites can cause circular redness, e.g. also flea bites. Should a circular reddening form around the puncture site, however, it should first be considered whether a tick bite can be remembered in the last few weeks. A red ring around the puncture site could be a sign of Lyme borreliosis, a tick-borne disease caused by special bacteria (Borrelia). The so-called wandering reddening (erythema migrans) is typical for this, as the reddening “migrates” along the skin and can therefore change its position or size. If such a skin pattern is present, possibly with accompanying symptoms such as fever or pain, a doctor should be consulted immediately.

Also read: How can you recognize Lyme disease?

Illustration therapy inflammation after an insect bite

Figure inflammation after insect bite: symptoms and therapy

Inflammation after an insect bite

  1. Redness
  2. swelling
    (Blisters or wheals)
    and warming
  3. Pus is indicative of a
    bacterial infection
    (See doctor)
  4. Inflammation of the lymphatic system
    also called "blood poisoning"
    designated (consult a doctor)
  5. Poison or other substances
    (e.g. saliva)
    A - injection site cooling
    with ice cream or quark compresses
    B - antihistamines in
    Tablet form or as gels and
    cortisone medication
    C - antibiotic therapy
    D - place cool with a
    sliced ​​onion
    E - The scratching after
    Possibility to omit completely

You can find an overview of all Dr-Gumpert images at: medical illustrations

How dangerous is an insect bite?

In most cases, an insect bite and its symptoms are primarily annoying, but completely harmless and only short-lived. The typical symptoms can range from none to severe pain, redness, swelling and warming of the surrounding tissue as a result of local inflammation. Itching occurs frequently as a reaction to the insect bite, caused by the release of endogenous substances such as histamine.

An insect bite can only be acutely dangerous if the person concerned suffers from an allergy to substances applied by the insect and therefore an "emergency cascade" is triggered in the patient's body shortly after the bite, which goes beyond a local reaction. This can lead to a wide variety of symptoms, such as pronounced swelling, for example in the area of ​​the airways, which can lead to shortness of breath or a general displacement of the fluid from the vessels into the surrounding tissue with the formation of Edema, come. Furthermore, a sharp decrease in blood pressure combined with an increase in heart rate occurs frequently. All in all, the resulting clinical picture of "allergic shock" is a vitally threatening clinical picture.

Read more on the topic: How do you recognize an allergy to a mosquito bite?

The insect bite is usually not dangerous over a period of several hours to days; a certain risk potential comes from potential complications, such as the spread of the inflammation or an additional infection with bacteria. These can have secondary effects on the entire organism and should definitely be assessed by a doctor and treated if necessary.

It can therefore be stated that the sting of a Central European insect can only be dangerous in a timely manner in connection with the presence of a corresponding allergy, for example to wasps or bees. But allergic reactions can also occur after a mosquito bite.

Read also under: Allergic reaction to a mosquito bite

root cause

The local tissue damage and possibly poison or other substances (for example, saliva) released by the insect during the sting result in the release of messenger substances in the area of ​​the insect sting. These messenger substances then trigger an inflammatory reaction. Histamine should be mentioned as an important messenger substance at this point. The release of these so-called inflammation mediators leads to the symptoms described. The reddening and overheating result from the fact that the messenger substances cause the vessels to widen in the area of ​​the puncture site. In addition, more fluid escapes from the interior of the vessel into the surrounding tissue, causing swelling. Pain is caused by the action of the inflammation mediators on so-called free nerve endings, which contain receivers (receptors) for pain.

The perception of the pain is then transmitted to the brain via nerve fibers.

After an insect bite, cells of the immune system are drawn from the blood to the area of ​​the puncture site. Among other things, these serve to break down foreign substances that have penetrated, such as insect venom. In the area of ​​the puncture site, the release of large amounts of histamine by so-called mast cells can lead to severe itching. Locally limited, but also pronounced allergic reactions in the case of hypersensitivity, are possible. The latter can be an acutely life-threatening event due to circulatory involvement or swelling of the upper airways. Fortunately, such severe gradients are a very rare occurrence.

Have you been stung and afraid that it could be a dangerous insect? The following article will already explain to you how dangerous an Asian (Japanese) bush mosquito and the black fly and its bite are.


The Diagnosing inflammation from an insect bite is a visual diagnosis. As a rule, the patient makes the diagnosis himself by observing the signs of inflammation and, if necessary, reminding himself of an insect bite in the corresponding area. This is more difficult if you cannot remember an insect bite or the symptoms do not match one at first glance. For example, a unnoticed insect bite as a gateway for bacteria have served and thereby a severe infection of the skin, subcutaneous tissue or lymphatic system have been caused. A doctor should then be consulted who can make the diagnosis by examining and touching the relevant area. Furthermore, in this case often add Blood tests the diagnosis. Usually, inflammation caused by a bacterial infection increased levels of inflammation in the blood.

If there is a suspicion of a tick-borne disease caused by bacteria, the so-called borreliosis, besides the assessment of the puncture site and its surroundings, the collection of certain blood values ​​is usually also required.

Pictures of those affected

4-day-old insect bite on the foot with redness, swelling and severe burning pain

4-day-old insect bite on the left foot with redness, swelling and pain.

Reddening of the skin after a 2 day old mosquito bite.

2-day-old insect bite on the arm with reddening, burning pain and severe itching

clearly visible swelling after an insect bite.

1 day old mosquito bite from a conventional mosquito.

1 day old mosquito bite with visible moisture


Depending on how bothersome the symptoms are after one Insect bite are felt, little or no supportive measures have to be taken. Treatment of an uncomplicated insect bite is symptomatic. Are particularly suitable Cooling of the puncture site for example with Ice cream or quark compresses. Gels, the so-called Antihistamines should be applied topically. This reduce the symptoms of inflammationby reducing or preventing the effects of histamine, which is instrumental in the inflammatory response. As a rule, these measures are completely sufficient for the symptomatic treatment of an insect bite. In special cases and with pronounced inflammatory reactions, under certain circumstances Antihistamines in tablet form, or cortisone medication are used. However, the doctor should decide on the use of these drugs.

An inflammation still needs medical treatment if it is caused by bacteria that got into the skin after the insect bite. Then it may be necessary Antibiotics given to prevent the infection from spreading and to contain the inflammation. Antibiotics are also used if a tick-borne borreliosis is suspected to prevent long-term complications.

Antibiotics for an infected insect bite

An infection and inflammation of an insect bite can be present if Bacteria infect the wound. To fight such inflammation, antibiotics should be taken, which either fight the bacteria directly or prevent them from multiplying. It should be borne in mind that only a small fraction of insect bites are secondarily infected by bacteria.
Inflammation that can only be traced back to the body's own reaction to the sting cannot be successfully treated by taking antibiotics. Even an allergic reaction can sometimes simulate an infection, but requires a different therapy than a bacterial infection.

Very severe redness, one open wound, Pain, fever, such as Pus formation are indications that it is a bacterial inflammation. In this case one should doctor who can confirm the suspicion and prescribe the correct antibiotic for the purpose. After the start of the Antibiotic therapy the symptoms of bacterial inflammation should get significantly better within 2 days.
If no improvement after 48 hours has occurred or the symptoms should even get worse again a doctor to be visited. To prevent the inflammation from flaring up again and to prevent the development of resistant bacteria, the Antibiotics always taken until the end of the planned therapy become.

Ibuprofen for an infected insect bite

At Ibuprofen it is a drug that has both analgesic and anti-inflammatory properties. However, taking ibuprofen for an inflamed insect bite is usually not useful. The inflammation of the skin after an insect bite is one local reaction of the body. Therefore, local therapies are usually sufficient to treat the symptoms of the insect bite. Since taking ibuprofen can be associated with some side effects, and ibuprofen has no causal effect on the bite, it should not be taken systemically. Only if strong pain If the sting occurs, it may be useful to take ibuprofen. If you have these symptoms, you should consulted a doctor as soon as possible to rule out an allergic reaction and infection or, if necessary, to initiate suitable therapy.

Read more about the effects of ibuprofen here.

Ointments for an infected insect bite

The main symptoms of an infected insect bite are usually itching, swelling and redness. They are caused by histamine, a messenger substance of the immune system, released by the body around the puncture site. Therefore, ointments that contain antihistamines are suitable to treat these complaints. Furthermore, cooling helps to alleviate the symptoms, since the injection site is often overheated due to the inflammation. Some ointments against insect bites therefore contain a combination of several ingredients that both counteract the increased release of histamine and have a cooling effect.

More on this topic: Fenistil®

Home remedies for an infected insect bite

There are a number of different home remedies that promise relief from the symptoms of an insect bite. It should be noted, however, that inflammation caused by a bacterial infection always requires medical care and should be treated with antibiotics. The symptoms of inflammation, which are the body's own response to the sting, can be relieved with some remedies.

To treat the swelling and overheating of the affected body part is the cooling Recommended using ice packs or the like. In many cases, cooling the sting can bring about a significant improvement in the symptoms.
Often a sliced ​​onion Recommended as a home remedy for insect bites. This can cool the area and therefore also promise relief. However, the onion is not expected to have a therapeutic effect. Since the ingredients can irritate the skin and in the worst case even cause an infection, this home remedy should be used replaced with a cool and damp envelope become. This also applies to all oils and creams that are used as home remedies against the inflammatory reaction to insect bites.

Homeopathy for an infected insect bite

In addition to traditional conventional medical therapy approaches against inflamed insect bites, the use of homeopathic remedies is available as an alternative therapy method. Depending on the literature, different remedies are recommended here, which are supposed to provide relief from an insect bite.
However, it should be noted: With a allergic reaction on an insect bite, or when the sting the respiratory tract concerns, it is about one medical emergency, which requires conventional medical treatment.
This also applies if a bacterial infection of the stitch is available. In this case, taking Antibioticsto fight the bacteria. Some practicing doctors offer both conventional medicine and homeopathic therapies and assess individually whether homeopathic therapy is recommended in each individual case.


Since the inflammation in an insect bite is a normal reaction of the body to the sting and is usually localized, it usually occurs within a short time to the uncomplicated regression of the signs of inflammation. Scarring is particularly possible if the skin is scratched. In the case of infections of the insect bite caused by bacteria, one Rapid medical treatment is necessary. The administration of Antibiotics may be needed to prevent the infection from spreading to surrounding tissues and the entire body. The aim is to heal the pronounced inflammation caused by the bacteria. Treated in good time, there is also a good prognosis in this situation. The same goes for the treatment of the Lyme disease.


If an insect bite becomes infected, the time it takes for the inflammation to completely heal can vary from person to person. The time it takes to heal depends largely on the cause of the underlying inflammation and the therapy.
If it is the body's own inflammatory reaction that occurs after each insect bite and not a bacterial infection of the bite, the inflammation usually decreases after a few days and the area heals without consequences. The situation is different with inflammation that is due to a pathogen. Rapidly initiated therapy can greatly reduce the duration of the inflammation in this case.

You might also be interested in: Duration of swelling from a bee sting.

Then you should consult a doctor

If there is a bacterial infection or an allergic reaction, see a doctor immediately.

Even if most insect bites heal on their own without medical therapy, in some cases it can be necessary and useful to see a doctor for clarification and therapy recommendations. This is especially the case if the insect bite is causing an allergic reaction. A doctor should also be seen if the sting affects the airways. Inflammation, which with severe pain and or fever go hand in hand and / or extensive redness or Pus formation indicate a bacterial infection, which should be treated with antibiotics. A doctor can confirm the diagnosis and recommend the appropriate medication. When an insect bite after 2 days worse symptoms it is advisable to see a doctor.


The Prevention of inflammation from insect bites consists mainly in the Avoiding the trigger, namely the sting itself. Depending on the type of insect, various measures can be useful. Fly screens, mosquito nets or the like can prevent insect bites in the home environment. Furthermore, sprays and lotions are available to keep insects away from the body.

To reduce the inflammatory response, the The injection site is cooled as quickly as possible become. Here, however, care must be taken not to let the strong cold act directly on the bare skin in order to avoid icing.

Everyone knows how excruciating itching can be. Hence, it is only understandable that it can be very difficult to resist the relief from scratching. Nevertheless, with itchy insect bites, it is very important to refrain from scratching if possible.

Scratching creates small wounds, which can then serve as entry portals for bacteria from the surrounding skin or the external environment. In addition, scratching can cause cosmetically annoying scars.

To relieve the itching and prevent the associated scratching, you can also Antihistamines in the form of gels be applied. These are available without a prescription from the pharmacy.

Nonetheless, self-discipline remains a crucial contribution to avoiding complications from insect bites.

Blood poisoning from an infected insect bite

The colloquial term blood poisoning is popularly used for two different clinical pictures. On the one hand, it is a clinical picture that affects the lymph vessels, on the other hand, an inflammatory reaction that affects the whole body, sepsis.

Read more on this topic: Lymphangitis - How Dangerous Is It?

Inflammation of the lymphatic system in the body (lymphangitis) is a possible complication of an insect bite. Overall, however, very few insect bites lead to lymphangitis. The disease is caused by bacteria that cause the inflammation. The inflammation of the lymph vessels is noticeable by a painful red streak under the skin. By taking antibiotics, the cause of the inflammation can be treated well and so-called "blood poisoning" can be treated.

Sepsis can also result from an insect bite. However, the likelihood of this is extremely small. It is a generalized inflammatory reaction which is a life-threatening medical situation. Sepsis requires immediate medical care in a hospital.

Read more on this topic: Blood poisoning after an insect bite

Inflamed insect bite on the ankle

The ankle is often the site of painful sores and insect bites.

Because of its location, the ankle is a common location for both insect bites and the development of inflammation. To avoid inflammation at this point, a Avoid rubbing on shoes or trousers become. Pre-existing inflammation should also padded so as not to hinder healing from mechanical irritation.
For sore spots in the context of an inflamed insect bite, the system can have a Association be useful to protect the wound from external influences and dirt.

Inflamed insect bite during pregnancy

The treatment an infected insect bite differs only minimally between pregnant women and other people. If symptomatic therapy is unsuccessful, it is advisable to ensure that some Painkiller such as lots of antibiotics during pregnancy not taken should be.
One caused by bacterial inflammation abscess however, it should also be used during pregnancy cleared and treated with antibiotics become. The attending physician should be informed about the pregnancy in order to select the right medication.

Further topics from this area

Insect bite

Especially in the hot days of the year, people suffer from insect bites. In addition to swelling and redness, the affected area of ​​skin is particularly itchy.
Here you get to the topic: Insect bite

Inflammation mosquito bite

Mosquito bites are usually accompanied by itching and swelling. In particular, the scratching of the mosquito bites can cause inflammation.
Here you get to the topic: inflammation mosquito bite

Mosquito repellent

Mosquitoes can be a nuisance, especially in the warm months. To protect yourself from insects, there are various means that can be used as mosquito repellent.

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