Insect allergy – how to avoid and treat

A insect allergy is a fairly common and usually mild problem. In Europe, more than 95% of allergic reactions are related to the stings of Hymenoptera, one of the largest groups of insects, including bees and wasps.

The venoms of these animals have a toxic action, so their stings can trigger reactions even in people without allergy problems.

However, there are many other insects whose sting or bite can generate an allergic reaction. This is the case for mosquitoes, flies, fleas and bedbugs.

Although most cases of insect allergy are not or not very serious, in extreme situations it can lead to death if not treated immediately.

What to do about insect allergy?

Causes and symptoms

Allergic reactions are exaggerated, or inappropriate, responses of the immune system to a substance that is normally harmless.

Among the most common allergies are those that come from insects that, through their bite or sting, leave venom on our skin. This happens especially during the warmer periods of the year.

In the case of Hymenoptera, including bees and wasps, their venoms consist of proteins with toxic and enzymatic actions.

The symptoms caused are usually local and mild. Among them, the most frequent are:

• Swelling at the site of the sting (up to 24 hours if the sting is less than 10 centimeters in diameter, or more than 24 hours if the sting is more than 10 centimeters in diameter);
• Pain;
• Itching;
• Burning sensation;
• Redness.

In the most severe cases, these reactions may be accompanied by fatigue, nausea and fever.

When the sting is on the head, especially in the area around the eyes, swelling of the eyelids may occur.

If it is on the face, especially in the mouth, the person may suffer from angioedema (swelling) of the larynx, with obstruction of the airway (responsible for transporting air to the lungs) and, therefore, risk of death.

The most serious situations are those where the allergic reactions are systemic.

In these cases, they usually appear a few minutes after the sting and present different degrees of severity:

• Grade I
  • Generalized itching;
  • Urticaria;
  • Redness;
  • General Discomfort;
  • Anxiety.

• Grade II – one of the above and two or more of the following:
  • Angioedema;
  • Chest pressure or tightness;
  • Nausea;
  • Vomiting;
  • Diarrhea;
  • Abdominal pain;
  • Vertigo.

• Grade III – one of the above and two or more of the following:
  • Shortness of breath;
  • Wheezing (whistling while breathing);
  • Stridor (high-pitched sound during breathing);
  • Difficulty swallowing or speaking;
  • Hoarseness;
  • Weakness;
  • Confusion;
  • Near-death experience;

• Grade IV – one of the above and two or more of the following:
  • Hypotension (very low blood pressure);
  • Shock;
  • Loss of consciousness (fainting);
  • Sphincter incontinence;
  • Cyanosis (purplish color of the skin).

Toxic reactions can also occur when the person experiences multiple bites simultaneously, which can be life-threatening.

What to do?

When a person is stung by a bee, the stinger usually remains on the skin. Therefore, after the sting, it should be removed as soon as possible with the fingernails or by using, for example, a credit card (scraping).

It is also important to keep the site of the bite clean with soap and water to avoid infection.

The area should not be compressed, as this may cause further injection of venom.

The following steps are usually followed:

• If it is a local reactionapplication of ice or cold compresses to the site of the bite;
• When it is a major local reactiona corticosteroid cream is also applied. You should also take an oral antihistamine for two to three days. For more severe cases, an oral corticosteroid is recommended (two to three days) ;
• At presence of itching and/or angioedemaTreatment usually includes an oral or intramuscular antihistamine and an oral or intravenous corticosteroid ;
• At more serious casesadrenaline, oxygen, and specific measures to treat anaphylactic shock may be required.

Patients with a history of severe systemic reactions should always carry an emergency device (pen or syringe) containing epinephrine for self-administration. They should also carry an antihistamine and a corticosteroid.

If bitten, allergic individuals should take an antihistamine and corticosteroid immediately.

If he begins to feel symptoms of systemic allergic reaction, he should be prepared to apply the injection of adrenaline on the anterolateral aspect of the thigh and through the clothing if necessary.

Vaccination against the venom to which they are allergic is the only effective treatment for people with a history of severe systemic allergic reactions.

Diagnosis

The diagnosis of insect allergy is made on the basis of the person’s clinical history, i.e., the type of allergic reaction, and the performance of a set of skin tests (on the skin) that identify the venom and the insect in question.

The presence of antibodies specific to heminopteran venom is also assessed.

Because a significant number of people test positive without a history of a sting reaction, it is advisable to perform these tests only if the person has had a previous episode of allergic reaction.

Prevention

People who are allergic to insects, especially those who have reacted to a bee or wasp sting, should take steps to protect themselves, knowing that insects usually only sting when they feel threatened.

In addition, it is important to know that insects become more aggressive in hot weather and in the presence of intense or fragrant odors.

It is therefore recommended:

• Avoid places where insects usually hang out (flower gardens, fruit trees, fallen tree trunks, firewood or garbage cans) ;
• Keep away from hives and wasp nests;
• Avoid the use of strong-smelling perfumes or cosmetics;
• Never walk barefoot, especially on lawns;
• Avoid wearing loose clothing with bright colors and floral patterns;
• Avoid eating and drinking outdoors;
• Do not make sudden movements or swarm when bees or wasps approach;
• If attacked, the person should protect his face with his arms or a garment;
• Wear a helmet and gloves when riding a bicycle or motorcycle;
• Inspect the car before entering and keep the windows closed;
• If you have ever had a severe allergic reaction, always carry the epinephrine device with you (never leave it in the car or at home).