Insect venom allergy

Insecticide allergy: description

Insect bites of bees and wasps are usually very uncomfortable. Not only does the bite hurt, but the toxin injected by insects also causes pain, extreme itching and swelling. These symptoms are normal after an insect bite. Sometimes, however, the immune system responds excessively. The entire cardiovascular system can then be disturbed in.

Over three percent of people in Germany suffer from an insect venom allergy. Almost a quarter of the population reacts particularly hard to an insect bite, at least locally. Wasp stings are apparently the most common cause of severe allergic reactions (anaphylaxis). In Germany, about 20 deaths occur annually due to an allergic reaction to insect bites.

The first stitch is not dangerous yet

An insect venom allergy develops after an insect bite. It can get worse from one stitch to the next. First, the immune system is “sensitized” after a first pass. It produces antibodies against certain substances in the insect venom (allergens). At the next stitch, the antibodies become active. A whole cascade of immune defense mechanisms is set in motion that can no longer be regulated. The allergic reaction spreads from the skin to the whole body.

Insect venoms contain hormonal messengers, proteins and enzymes such as hyaluronidases and phospholipases. The messengers histamine and serotonin lead to an expansion of the skin vessels. Histamine also causes a strong itching. The hyaluronidases and phospholipases cause the poison to be redistributed.

Insecticide allergy: symptoms

In an insect bite, the injected poison causes a painful redness and swelling around the puncture site. The redness is accompanied by a strong itching. Most of the symptoms disappear within a day. With a swelling that is more than ten centimeters in diameter and lasts more than a day, it is called a severe local reaction.

First signs of severe allergy

If the allergic reaction spreads to the whole body, respiratory distress, circulatory problems or stomach and intestinal complaints may occur. Various proteins affect the central nervous system, which can lead to dizziness and nausea. In severe cases, the cardiovascular system collapses completely.

The first sign of a severe allergic reaction is often tingling of the palms, scalp or tongue. The skin reddens, the affected skin swells. Dizziness and palpitations can accompany these symptoms. Breathing is becoming increasingly difficult.

An anaphylactic reaction is very often in two phases. Symptoms such as mild respiratory distress, nausea or dizziness often start minutes after the bite and gradually fade away. After a few hours, a reaction occurs again. This can then take on much heavier forms and even be life-threatening.

Mosquito bites: allergic reaction

Since there are certain substances in the venom of the mosquito against which the human immune system can produce antibodies, an allergic reaction to mosquito bites often occurs. Mosquitoes or brakes usually trigger an allergy limited to the skin. The injection site swells over a large area, itches, is red and overheated. Extremely rare is the cardiovascular system affected. The symptoms often last longer than a day. A scar may remain at the injection site.

Insect venom allergy: causes and risk factors

The development of an insect venom allergy does not require a genetic readiness for allergies. This means that people with a pollen allergy, for example, do not have a higher risk of being allergic to an insect bite.

Particularly at risk for insect venom allergies are people who come into contact with bees or wasps more frequently. These include, for example, beekeepers, gardeners, farmers, fruit and bakery sellers.

Furthermore, people over the age of 40 and people with asthma or cardiovascular disease are at risk of suffering from anaphylaxis. People with so-called mastocytosis are particularly at risk for insect venom allergy. This is a rare disease in which many mast cells of the immune system collect in the skin or internal organs. The mast cells heat the excess immune defense even further.

Certain medications, such as beta-blockers or ACE inhibitors, may increase the risk of insect sting allergies or increase the allergic response.

After an insect bite, the immune system has mistakenly formed antibodies against components (allergens) of the poison. The wasp venom can contain up to six different allergens, the bee venom about twelve. The mosquito bite allergy is triggered by allergens in the saliva of the mosquito. The most important allergens in insect venom are:

• allergic reaction Wasp sting: phospholipase A1, hyaluronidase and antigen 5
• allergic reaction bee sting: phospholipase A2, hyaluronidase, acid phosphatase, serine protease
• allergic reaction mosquito bite: Salivary protein rAed a2

Insect venom allergy: examinations and diagnosis

If there is a suspicion of a bee or wasp sting allergy, the doctor will first ask the following questions:

• Which insect has stung you?
• What symptoms have appeared after the sting?
• Have you ever been stung by a bee or wasp? How was the symptoms then?
• Do you suffer from chronic diseases?
• Do you suffer from other allergies?
• Do you take any medicine?

This is usually followed by a physical examination, a so-called prick test and a blood test.

prick test

In a prick test, various allergens in teardrop form are applied to the inside of the forearm. It then waits one or more days to see if the affected areas of the skin show signs of redness or swelling. These speak for an allergic reaction. In a bee sting allergy, for example, the skin on which the bee venom was applied becomes reddened. Sometimes the allergens are also injected under the skin.

Antibody detection in the blood

If an insect venom allergy exists, the antibodies produced against the allergens of the insect venom are often found in the blood. The investigation may confirm the suspicion of an insect venom allergy. Since the antibodies can also be found in the blood for other reasons, the proof is not conclusive, but merely another indication of an insect venom allergy.

Insecticide allergy: treatment

It is especially important for people with an insect venom allergy to avoid every insect bite as much as possible. Furthermore, those affected should always carry an allergy passport and an emergency kit.

Therapy of the local skin reaction

If the sting of the insect is still in the skin, it should be pulled out carefully so that not more poison gets into the skin. An allergic reaction limited to the skin should first be treated locally. For this purpose, you can cool the puncture site with wet envelopes, cool packs or ice cubes.

Cooling should be left for about 20 minutes and repeated at intervals of several hours. Cooling ointments or gels relieve the itching. In severe skin reactions, you should take an antihistamine. After that, it is advisable to see a doctor.

In insect bites in the mouth or tongue, ice cubes can relieve the pain. In such a case, however, a doctor should be consulted immediately or the rescue service should be alerted. It is not advisable to drink liquids, as those affected by the swelling in the throat can easily swallow.

Therapy of the allergy symptoms of the body

The emergency kit contains medications that can be taken in case of emergency before the arrival of the doctor. In case of shortness of breath, a spray is available that dilates the bronchi and allows those affected to breathe again. For circulatory problems, adrenaline can be self-administered via an autoinjection syringe. Furthermore, an antihistamine and a cortisone-containing drug are in an emergency kit.

Patients with severe allergic symptoms have to be monitored at the hospital for some time, as later physical reactions can occur.

Hyposensibilisierung

An allergy can be treated by a so-called hyposensitization. In several sessions the body is “desensitized” to the allergens. The severity of insect venom allergy decreases significantly over time. Hyposensitization is a lengthy process and not suitable for everyone.

Insect venom allergy: disease course and prognosis

Hyposensitization can favorably influence the course of the disease. In particular, in children after such a therapy, a long-lasting protection against an insect venom allergy is proven. Furthermore, bees, wasps, hornets and mosquitoes should be avoided if possible. The following measures can help to keep insects away from the body:

• Do not eat and drink outside in summer
• Do not drink from bottles or beverage cans
• You should not be in the vicinity of trashcans, rubbish bins, animal enclosures or fallen fruit during the summer
• Do without perfume or perfumed cosmetics
• Do not perform any hectic movements when bees or wasps are nearby
• Prefer clothes with lighter colors
• Do not walk across the meadow barefoot or with open footwear

Measures to avoid mosquito bites:

• Secure window grilles and mosquito nets
• Use mosquito repellent
• Wear long clothes with solid fabrics

The risk of being stung by an insect is increased especially in the months of April to November. During this time, it is important to carry emergency kit and allergy passport if one Insect venom allergy was diagnosed.