Why is my insect bite getting bigger

Mosquito bite with consequences

Calla Katharina Wilhelm can no longer say which insect it was that stung. Probably a mosquito.

"All I noticed then was that my wrist was getting thicker and thicker and then also began to turn red. And the redness grew over the next 24 hours to over the elbow at a rate that I was really scared and then thought, off to the doctor. "

Doctors speak of a "wound rose" when the skin turns red over a large area after an insect bite. This year significantly more people are affected. Once there are more mosquitos, a result of the floods in Germany. And besides, according to Dr. Julia Börger, internist from Hanover, the blood-sucking pests are particularly aggressive this year:

"I could imagine that this has to do with the fact that the insects are possibly more aggressive overall - due to environmental toxins, for example, that a local reaction is more violent, and the germs are simply brought into the tissue by scratching."

However, the germs do not come from the insect. Rather, it is bacteria, especially streptococci, that colonize human skin. Since the stitches are very itchy, the pathogens are rubbed into the wound and trigger the infection there, explains Professor Matthias Stoll from the Hannover Medical School:

"This is where lymph emerges. This is, of course, an" ideal breeding ground ", so to speak, then the streptococci can multiply on the surface, and then they have their enzyme set and can thus, to a certain extent, move into the depths.

Streptococci are aggressive pathogens. If they get into the bloodstream, there is a risk of sepsis - in the worst case multiple organ failure with fatal consequences. Older people with previous illnesses such as diabetes are particularly at risk. Younger people also get the disease, but usually not that severely. In all cases, go to the doctor if there is any indication of a rose.

Julia Börger:
"" You can tell by the reddening of the puncture site, which then quickly gets bigger, gets hot, hurts, spreads further, is relatively smoothly delimited to the still healthy surrounding tissue. "

The reddening begins a few hours after infection and spreads quickly. Fortunately, strep are relatively easy to treat. Once again Prof. Stoll.

"" The treatment of choice is the classic old penicillin because you can dose it in incredibly high doses without harming the body. It mainly harms this type of pathogen and does not destroy all of the other bacteria present in the body, but only relatively few of them. That makes fewer side effects.

Those who do not scratch the puncture site have a good chance of avoiding an infection. That is why ointments that stop the itching are a good choice. Just not spit. This is because the saliva also contains streptococci, especially in the case of tooth decay. In principle, the bacteria can become a problem with any wound. In the case of insect bites, however, the risk of a sore is particularly high, warns Dr. Jochen Wedemeyer from the Robert Koch Clinic in Gehrden near Hanover:

"The most important thing is - I think - it doesn't itch. By scratching, we open the skin and thus represent a gateway for pathogens. It's best to simply keep your hands off it.