What helps in wasp and mosquito stings
They make the "Sss" sound and then sting: Overcoming a summer without mosquito or wasp bites - hardly possible. What relief brings and why household remedy onion causes damage.
A summer day by the lake could be so beautiful. But if not for the many mosquitoes that see us humans as a feast. Or the wasps, swarming over the meadow, making us accidentally step on them barefoot. A allergologist explains what happens in our body when we get stung by insects, what common household remedies have in common, and when a swelling is unusually large.
How does our body react to insect bites?
Mosquitoes want our blood, as they feed on it. And to make it easier to suck, they have their tricks: "They inject their saliva into the bite site. And it contains substances that prevent the blood from clotting", explains Prof. Thilo Jakob, Director of the Department of Dermatology and Allergology at the University Clinic Gießen.
The fact that a mosquito bite itches is due to certain proteins in the insect's saliva. They are foreign to our body, activating our mast cells. "They are located in the skin and belong to its defense system", explains Thilo Jakob. In the following, certain messenger substances are released in the skin: They cause the bite site to itch and widen the vessels - the bite swells up.
And with bee or wasp stings? These insects do not want our blood, but rather defend themselves. "They therefore inject poison into the skin. The goal is: whoever disturbs them should leave them alone", describes Jakob. Since the poison is also a foreign substance, an immune reaction occurs in this case as well. It signals a stinging pain, the skin turns red and swells, and it itches.
How should I treat a wasp or bee sting correctly?
If there's still a stinger in the skin, that means the bee is the culprit. The Health Knowledge Foundation advises removing the stinger as soon as possible after a sting. Help can be found in a wallet: With the edge of a plastic card, one can carefully scrape off the stinger.
However, there is one taboo: squeezing the sting site with your fingers. By doing so, one applies pressure on the stinger and presses even more poison into the skin. And then: cool, cool, cool. This helps to slow down the spread of the poison. It is also sensible to disinfect the sting site.
Special case: If the bee or wasp has stung in the mouth, this is a case for emergency number 112. Swelling of the lips or tongue can threaten life-threatening suffocation. Until help arrives, cooling is essential - for example, by licking ice cubes and placing a cool compress around the neck.
Can spittle relieve the symptoms of insect bites?
Yes, but not because it contains magical substances. "Spittle is nothing more than a fluid that is always available - and that cools the bite", says Thilo Jakob. Since there is moisture on the skin, a light breeze can already draw away its heat - so the cooling effect works.
And it inhibits the inflammation that lies behind every insect bite and causes its annoying symptoms. According to the doctor, this cooling effect is also what the numerous household remedies against insect bites contain: cucumber slices, cabbage leaves, yogurt - or onion.
At Jakob's warning, he indeed advises caution with onions. For they contain a great deal of acid, which can lead to skin irritations. "We have seen patients who applied onion slices with a thick bandage on their skin for 24 hours," Jakob recounts. That's too much of a good thing.
What else can help?
If the mosquito bite is still fresh, heat can help alleviate the itch. More specifically, certain wands or "healing sticks" that are pressed onto the affected area and give off temperatures of 50 degrees Celsius or more. "This is supposed to inactivate the proteins in the mosquito's saliva that have entered the skin through the saliva," Jakob explains.
Another effect of the heating sticks: The pain caused by the heat overlays the itch. Both sensations are transmitted through the same nerve fibers.
Relief can also be brought about by an antihistamine applied to the skin. Antihistamines are a drug group primarily used for allergies. "I recommend gels, as they also cool down," says Jakob, who is also a board member of the German Dermatological Society.
Scratching isn't good, right? But why?
Scratching may result in a skin infection, warns the doctor. "When the skin is scratched, bacteria can settle and multiply - then the bite cannot heal properly." Anyone who suspects a skin infection can consult a pharmacist, as there are over-the-counter antiseptic creams available. If it doesn't improve, a visit to the family doctor is advisable.
Medical examination is also important when a rash spreads around the bite, which becomes larger and larger and is accompanied by fever and chills. This could be a so-called wound rose, caused by bacteria - specifically, streptococci. "It's rare. But if it occurs, it must be treated medically," says Thilo Jakob.
Why do some bites swell so much?
The degree of swelling sometimes depends solely on the nature of the tissue. A typical example: "If you have a mosquito bite on the eye, the entire eye can swell," explains Jakob. Mosquito bites on the legs often swell significantly. This is due to the fact that there is a certain water pressure in the legs.
There are also excessive bite reactions that can hide behind strong swellings. "There are people who react strongly to bites," says Jakob.
This applies especially to wasp and bee stings. In medicine, a normal reaction to these stings is a swelling up to a diameter of 10 centimeters. "If someone was stung in the hand and the swelling reaches the elbow, then we speak of an excessive bite reaction," says Jakob.
With mosquito bites, such reactions can also occur, but there is no clear size limit here. At the very least, when a bite becomes hand-sized, the reaction should be medically evaluated.
Is an excessive bite reaction then an allergy?
Thilo Jakob distinguishes an actual insect venom allergy from such an excessive bite reaction. For: Characteristic of an insect venom allergy is that symptoms occur independently of the sting site. Systemic reaction, the doctors call it.
"If someone was stung in the foot and suddenly itches all over the body, shows shortness of breath and dizziness, then that's a clear sign that the entire system is reacting," Jakob gives an example.
Such events must be examined medically without a doubt, advises the doctor. As they may develop into a potentially life-threatening allergic shock - an anaphylaxis. The good news: there is a treatment called specific immunotherapy, where the body is gradually accustomed to insect venom. This means that no allergic reaction occurs upon a subsequent sting.
Very rarely, such systemic reactions can also occur after mosquito bites. According to Jacob, the same principle applies. If one experiences symptoms such as hives, dizziness, shortness of breath or tightness in the throat 10 to 30 minutes after the bite, one may have an allergy to substances the mosquito has introduced into the body. In any case, consult a doctor.
Did you know that wasps are not just insects, but they belong to the order Hymenoptera, which also includes bees and ants?
Furthermore, it's a common myth that wasps are beneficial for controlling insect populations, such as aphids and caterpillars. However, while they do consume some harmful insects, they can also be harmful to other animals, including birds and small mammals, as well as humans. The venom from a wasp sting can cause pain, swelling, and in severe cases, anaphylaxis.
