Dermatology-Online

Itchy mosquito bites - what to do?

introduction

Itchy mosquito bites are not infrequently the reason for scratched and consequently inflamed skin areas.

It is not the secretion brought in by the mosquito through a bite that is decisive for the itching, but rather the reaction of our own body to the "foreign matter" brought in.

The body's own inflammatory reaction is the cause of the negative sensation on the skin, while at the same time it is a good indicator of the functioning of our immune system.

This is because it signals that a potential pathogen has been detected.

Why do mosquito bites itch?

The reason for the tolerable symptom "itching" is the reaction of the body's own defense system to unknown, foreign substances such as the saliva of a mosquito.

So-called mast cells release the messenger substance histamine as soon as they recognize a foreign substance, so that other cells of the immune system are attracted.

This is to result in the potentially harmful substance being eliminated from the body as quickly as possible.
In order for the messenger substance to be effective, however, it has to stimulate blood flow to the affected area - after all, the cells of the immune system reach the desired location via the bloodstream.

The first thing the person concerned can recognize is local reddening, swelling and overheating of the skin, as the blood vessels have been widened by the messenger substance.

However, it also irritates special nerve endings in the skin, which those affected then perceive as itching.
The itching symptom is therefore a neurological phenomenon. If no more histamine reaches the free nerve endings, the itching stops.

However, before this is the case, the body's defense reaction in the form of inflammation must be completed.

Why is it that mosquito bites itch for weeks?

There are several reasons why mosquito bites can itch for weeks.
In general, the body tries to “encapsulate” foreign substances in order to organize them with the help of the immune cells and to transport them out of the body in a targeted manner.

During this process, so-called phagocytes take up small portions of the foreign substance and digest them into harmless degradation products for the body.
If this degradation process has not yet been completed, or if part of the foreign substance gets back into the surrounding tissue during this time, this can trigger a renewed inflammatory reaction with the result “itching”.

Manipulating the mosquito bite, which is already healing, can cause persistent itching. Another possibility is the so-called "delayed defense reaction".

The name suggests that the immune system reacts with a time delay to the mosquito bite.
The consequence is the appearance of typical allergy symptoms after an individual period of time.

Here it must be clarified in each individual case whether it is a standard variant or whether there is an indication of a disease of the immune system.

Read more on the subject under: Inflammation after a mosquito bite

How can you relieve or stop itching?

As banal as it sounds - keeping the affected extremity or body part gently is the best way to relieve itching.

If the affected part of the body is moved as little as possible, it is supplied with less blood compared to a stress reaction and the secretion from the mosquito bite does not spread unnecessarily further via the bloodstream into the surrounding tissue.

Local cooling can help here, as it ensures that the blood vessels contract and the localized overheating is reduced.

Medicines should only be used in the event of severe reactions to mosquito bites, as side effects are always to be expected.

Read more on the subject under: Home remedies for mosquito bites

Antihistamines

The name "antihistamines" already reveals the effect of this group of drugs.
They work against the messenger substance histamine, which is released as part of an allergic reaction to mosquito bites and the symptoms that are stressful for the person concerned

Itching,
Redness and
Makes swelling.

As a rule, they are taken in tablet form when needed and develop a soothing effect after a short time.

Their most common disadvantage is their most well-known side effect - fatigue.

Cortisone ointment

Cortisone is an immunosuppressive agent, which means nothing more than that it suppresses the body's own reaction of the immune system.

In the event of a mosquito bite, the active ingredient prevents the inflammatory reaction from progressing.

Ointment applied externally, however, has almost no effect on the mosquito bite, as the active ingredient is almost not absorbed through the skin.

It is much more effective to take tablets if there is a clear reaction to mosquito bites in the form of, for example, enormous swellings or blistering.

Home remedies for the itching

From the outset it must be said that home remedies are only effective against mosquito bites to a limited extent.

For those affected, the placebo effect is particularly effective, but this should not be underestimated, especially for children.

The application of onion juice or essential oils is only recommended to a limited extent, however, as this can trigger another allergic reaction. They also tend to irritate the affected area of the skin and trigger the inflammatory reaction unnecessarily.

The best home remedy for itching is local cooling of the affected area.

It should only be done intermittently so that the skin can again be supplied with sufficient blood in the cooling-free intervals.

During the cooling itself, the superficial nerve endings are numbed and the blood vessels narrowed, so that both the itching and the accompanying symptoms such as reddening and overheating are reduced.

If the cooling is too uncomfortable or painful for you, you can also elevate the affected extremity.

Here, too, the effect is that the blood flow is reduced by gravity.

Why do mosquito bites itch more when you scratch?

The scratching is nothing more than mechanical irritation of the skin.
Similar to a massage, this stimulates the blood flow to the tissue around the mosquito bite.

The effect is that the inflammation-promoting secretion brought in by the mosquito is better distributed via the bloodstream and can ignite an inflammation over a larger area as part of an allergic reaction.

As a result, more inflammatory cells are activated by the body and there is a further release of the messenger substance histamine, which causes the itching and makes it subjectively more intense.

Other accompanying symptoms

Almost every mosquito bite leads to an activation of the immune system, which manifests itself as inflammation in those affected.
The typical symptoms of inflammation are "reddening, overheating, pain and swelling", although they differ in severity from individual to individual.

Those affected can usually see a red, warm and painful area around the mosquito bite.

If the immune system overreacts, those affected often develop a fever and feel sick.

This is based on the body's attempt to kill the pathogen with the increased body temperature.

If the body's defense reaction to the foreign substance "mosquito saliva" is even stronger, an unusually intense swelling of the mosquito bite can also be seen, which is accompanied by a significant increase in size and an accompanying feeling of heaviness in the body part.

If a fluid-filled blister finally forms in the area of the injection site, those affected should take this as a serious indication of an excessive reaction in their immune system and consult a doctor.

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