Insect bite allergy
Allergy to insect bites
Insect bite allergy is an immunologic reaction arising from immediate- or delayed-type hypersensitivity in response to contact with venom or insect saliva. Allergic manifestations may be local, including erythema and edema, or generalized, involving multiple organs and systems.
Signs of allergy to insect bites
Allergies to insect bites may manifest with localized symptoms. At the site of the bite, a red papule with a central dot (bite site) and a corolla of inflammation with swelling around it forms. The size of the inflammation zone can vary from a few millimeters to 10 to 15 centimeters in diameter. Blisters or blisters may develop at the site of the bite. Depending on how sensitized the body is, either mild swelling with mild erythema or severe swelling that extends far beyond the bite site and causes markedly redness may occur at the bite site.
If a systemic reaction develops, the swelling can spread to the surrounding tissues, and the person may feel unwell, feel weak, be sluggish, and have a fever. The most severe manifestation of allergy is anaphylactic shock. This causes the airways to swell, resulting in difficulty breathing, bluish skin, and loss of consciousness. If such symptoms develop, an ambulance should be called immediately.
Allergic reactions to the venom of stinging insects, such as wasps, bees, bumblebees, and hornets, are usually more severe than those to the bites of blood-sucking insects. Stinging insects are more likely to cause serious systemic reactions, including anaphylactic shock. The faster the reaction develops, the more severe the consequences may be.
Allergic reactions to the bites of blood-sucking insects, such as mosquitoes and midges, usually manifest after 6 to 8 hours and are rarely systemic. However, a local reaction can be quite troublesome. For example, erysipelas-like skin inflammation sometimes develops after a midge bite.
Forms of allergic reactions to insect bites
Allergic reactions to insect bites can manifest in two main forms:
Limited
- The pathological process is limited to the bite site.
- Local symptoms such as redness, swelling, and pain in the affected area usually disappear within a few hours.
Common
- The process involves other organs and systems of the body.
- General symptoms: widespread rash, itching, difficulty breathing, dizziness, weakness.
- In severe cases, anaphylactic shock and angiedema can develop.
Causes of Allergic Reactions to Insect Bites
Allergic reactions to insect bites are usually caused by hymenoptera, such as wasps, bees, and hornets. During a bite, a venom containing specific proteins enters the skin. These proteins stimulate the release of biologically active substances, leading to local vasodilation, the invasion of inflammatory cells, and the release of cytokines that support inflammation.
Bites of blood-sucking insects, such as midges, gadflies, mosquitoes, fleas, can also cause allergic reactions. Various biologically active molecules that trigger hypersensitivity enter the skin along with saliva.
Allergic reactions can occur and when in contact with insect waste products. For example, contact with the waste products of butterflies or cockroaches can cause allergic rhinitis and conjunctivitis.
A hereditary predisposition also plays an important role in the development of allergic reactions.
Methods for diagnosing allergies to insect bites
Diagnosis of insect bite allergy begins with a history and thorough clinical examination. It is important to find out whether the person or close family members have any allergies. The skin should also be examined closely.
Laboratory tests include measurement of total immunoglobulin E (IgE) and identification of specific IgE in the blood for various allergens (allergopanels). In addition, skin tests can be carried out: an allergen is applied to the skin, a microhole is made with a special tool, after which the reaction of the skin in the form of a blister is assessed for half an hour. The size of the blister helps determine the presence and severity of the allergy.
Careful medical history should be obtained to distinguish contact dermatitis from urticaria. When examining the bite site, you can notice a papule with a point in the center - a characteristic trace of an insect bite.
Treatment
To treat generalized allergic reactions to insect bites, the patient is hospitalized and given detoxification drugs and high-dose corticosteroid hormones.
Local reactions are usually treated with first- and second-generation antihistamines. Topically, antipruritic, drying, anti-inflammatory, and anti-edematous ointments, including those containing corticosteroids, are used. Fenistil gel, Psilo-balm, zinc bolt and Calamine lotion are suitable for relieving itching. Troxevasin gel and Traumel help to relieve swelling faster.
If secondary infection is present, antifungal and antimicrobial drugs are added.
If you have an allergic reaction to insect bites, be sure to consult an allergist. He can offer a modern treatment method - ASIT (allergen-specific immunotherapy).
Allergic to ingredients in repellents. It is recommended to test a small area of skin before use to make sure there is no allergic reaction.
It is important to follow the manufacturer's instructions when using repellents to ensure maximum efficiency and safety. For example, people should not apply repellent to the face or eye and should avoid inhaling aerosols. After returning from places where the presence of insects is possible, it is worth thoroughly washing the remnants of the repellent from the skin with soap and water.
Prevention
In addition to using repellents, there are a number of additional measures for the prevention of insect bites. These include wearing long sleeves and pants, using mosquito nets, especially indoors and outdoors, and limiting outdoor activities in the early morning and evening hours when insects are most active.
Following these recommendations, you can significantly reduce the risk of allergic reactions to insect bites and make outdoor activities more comfortable and safe.
