Causes of an allergic reaction to a mosquito bite | Allergic reaction to a mosquito bite

Causes of an allergic reaction to a mosquito bite

If a mosquito bites into an area of skin, it spreads a small amount of its saliva there. The mosquito’s saliva inhibits the clotting system at this point. This is necessary so that the mosquito can suck off blood without it clumping together through the human clotting system.

The body perceives the bite and the injection of the saliva as a disturbance and triggers a cascade of defence mechanisms. The hormone histamine is also released as part of these mechanisms. Histamine is a messenger substance and plays a role in allergic and inflammatory reactions.

At the affected site, the blood vessels dilate so that many substances can reach it as quickly as possible. This is the cause of the redness. The dilated vessels also cause fluid to be stored in the tissue, resulting in the familiar swelling after a mosquito bite.

The itching is caused by the irritation of so-called C-fibres. The C-fibres are slowly conducting nerve fibres. They are particularly responsible for the perception of pain.

Diagnosis of an allergic reaction to a mosquito bite

First of all, it is discussed in a doctor’s consultation whether it is really an allergic reaction to a mosquito bite or whether another insect allergy could be present. Then the individual symptoms are discussed. For the doctor, the symptoms that go beyond the usual skin reaction are particularly important.

Then the doctor can also perform a so-called provocation. In this case, a little of the mosquito saliva is applied to a skin area in a controlled environment and is brought into the skin with a lancet. The reaction to this allergen is then observed. In addition, antibodies can also be detected in the blood. These tests should be carried out once shortly after the insect bite and then again a few weeks later.

Duration of an allergic reaction to a mosquito bite

By definition, an allergic reaction to a mosquito bite lasts at least 24 hours. The skin reactions usually heal within a few days. The exact duration depends on the severity of the skin rash. Taking antiallergic drugs can also have a positive effect on the duration.

Course of disease

The first reactions can be seen after seconds. As the allergy to mosquito bites is one of the allergies of the immediate type, all other symptoms also develop very quickly, usually within 30 minutes. If swelling of the face or neck with shortness of breath develops shortly after a mosquito bite, a doctor should be consulted as soon as possible.

Allergic reaction to a mosquito bite in a child

In children, an allergic reaction to a mosquito bite can quickly show pronounced symptoms. They show similar symptoms to adults. In the case of pronounced allergies, nausea, vomiting and strong palpitations may occur.

However, children do not have as many reserves as an adult, so an allergic reaction must always be taken first. In the worst case an anaphylactic reaction can be triggered by a mosquito bite. This can then be accompanied by shortness of breath and circulatory problems.

If in doubt, a doctor should be consulted early on, as life-threatening conditions can quickly arise in children. For this reason, it is also recommended that children be hyposensitised if they are allergic to mosquito bites. A small dose of the allergen is injected under the skin at regular intervals. This should help to reprogram the immune system so that no excessive immune reaction is triggered.