How dangerous is an insect bite?

In most cases, an insect bite and its symptoms are mainly annoying, but completely harmless and only of short duration. The typical symptoms can range from none to severe pain, redness, swelling and warming of the surrounding tissue as a result of local inflammation. More often than not, itching occurs as a reaction to the insect bite, caused by the release of the body’s own substances, such as histamine.

An insect bite can only be acutely dangerous if the person affected 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 in the area of the respiratory tract, for example, which can lead to shortness of breath or even to a general shifting of fluid from the vessels into the surrounding tissue with the formation of edema. In addition, there is often a strong decrease in blood pressure in combination with an increase in heart rate.

All in all, the resulting clinical picture of “allergic shock” is a vitally threatening clinical picture. Over a period of several hours to days, the insect bite is usually not dangerous; a certain risk potential is posed by potential complications such as the spread of the inflammation or an additional infection with bacteria. These can secondarily cause an impairment of the entire organism and should definitely be assessed and treated by a physician. 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 even after a mosquito bite, an allergic reaction can occur.

Cause

Due to local tissue damage and, if necessary, poison or other substances (e.g. saliva) released by the insect during the bite, messenger substances are released in the area of the insect bite. These messenger substances then trigger an inflammatory reaction. An important messenger substance at this point is histamine.

The release of these so-called inflammation mediators leads to the symptoms described above. The reddening and overheating is caused by the fact that the messenger substances cause a dilatation of the vessels in the area of the puncture site. In addition, increased fluid from the inside of the vessel passes into the surrounding tissue, causing swelling.

Pain is caused by the influence of the inflammation mediators on so-called free nerve endings, which contain receptors for pain. The perception of pain is then transmitted to the brain via nerve fibers. After an insect bite, cells of the immune system are lured from the blood into the area of the bite.These serve, among other things, to break down foreign substances that have penetrated, such as insect venom.

In the area of the bite site, the release of larger amounts of histamine by so-called mast cells can lead to severe itching. Localized allergic reactions are also possible, but in the case of hypersensitivity even pronounced allergic reactions are possible. The latter can be an acutely life-threatening event due to circulatory involvement or swelling of the upper respiratory tract.

Fortunately, such severe courses are a very rare occurrence. You were bitten and are 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 blackfly and its sting are.