Description and photo of mosquito bites in children and adults

With the arrival of spring and summer, living creatures also become active. Various bugs - cockroaches wake up after winter hibernation, and during this period the biting season begins. Mosquitoes, midges, horseflies, ticks, flies, bees, wasps, etc. And if you add to this the household nippers, then this is a whole army that strives to bite, sting, and pinch you. Who bites us and what marks leaves on the skin, let's figure it out.

General information

There are a huge number of different types of insects in the world, with which people come into contact to one degree or another, both during rest and during various jobs. Accordingly, bites/stings of people by insects of one type or another are extremely common. Insects can bite/sting both for defensive purposes and for the need for nutrition, when a person can act as a link in the food chain. The consequences of contact with insects can vary widely - from minor redness and mild itching at the site of the bite to allergic reactions of varying severity. An allergic reaction to bites/stings (insect allergy) by insects is caused by the entry of various toxic substances into the human body:

• biogenic amines ( serotonin histamine kinins , norepinephrine );
• enzymes (acid phosphatase , phospholipase A , hyaluronidase );
• peptides ( apmin , neurotoxin , mellitin ).

The content and amount of toxic substances depends on the type of insect. Thus, with the bites of stinging insects, for example, bees, the toxic effects are caused by mellitin ; os - neurotoxin . Allergic reactions are caused predominantly by the sensitizing effect of various enzymes: hyaluronidase, phospholipase, A/acid phosphatase. When biting non-stinging insects, pathological reactions are caused by biological amines, anticoagulants and toxic substances. Persons with increased sensitivity (allergy sufferers) have especially pronounced reactions to insect bites. Insect bite code according to ICD-10 is W57. At the same time, in ICD-10 there is no classification of bites/stings by type of insect.

Insect bites/stings are widespread, occur mainly in the warm season and in the vast majority of cases end successfully - the victim exhibits mainly local signs of the bite, which disappear on their own within a few days. But in almost 5% of people, insect bites lead to the development of local/general allergic reactions ( urticaria / angioedema ). And in about 1% of people, bites/stings are accompanied by neurotoxic effects with the risk of developing seizures and, much less often, death of the victim. The main risk group is hunters, children, mushroom pickers and people whose professional activities take place outdoors and often come into contact with insects and their metabolites.

Representatives of the insect fauna are able to quickly spread throughout the territory, both due to their own mechanisms of movement, and passively with the help of wind/by fixing on the skin of an animal. The concentration of insects is determined by environmental factors: humidity, temperature, wind strength. Accordingly, in entomologically disadvantaged areas, the likelihood of insect bites/stings/contacts with metabolites is extremely high.

Of particular danger to humans is an allergic reaction to the venom of various hymenoptera stinging insects (bees, hornets, bumblebee wasps, certain types of ants), which can often result in anaphylactic shock and sometimes the death of the victim. It should be taken into account that not only insect bites, but also larvae/pupae, as well as their waste products (feces/fragments of dead insects), which enter the body through direct contact with the skin/inhalation, can act as an allergen.

Sensitization to the venom of stinging hymenoptera develops more often in patients under 20 years of age and especially often in children/adolescents. Bites of some types of insects are common (bites of mosquitoes, bees, mosquito bites, flea bites, ant bites; other species are relatively rare - the bite of a praying mantis, centipede (scolopendra), two-tailed, horsefly, some flies, in particular the gadfly, elk lice). Insect bites in apartments are much less common. The most common mosquito bite occurs when they enter the home and bedbugs (they bite in bed at night).

Many people are interested in whether cockroaches bite? Cockroach bites are very rare and occur only in extreme situations, when insects find themselves in unfavorable living conditions (lack of water and food), especially against the backdrop of a sharp increase in their population and the deposition of larvae.

People often wonder how dangerous the bites of certain insects are, for example, whether elk lice are dangerous for humans or the bites of wasps, gadflies, centipede bites, and so on. It should be noted that there is no clear answer to such questions. The reaction to an insect bite, regardless of its type, is largely determined by the dose (number of bites), the location of the bites and, to a large extent, the individual sensitivity of the body. Thus, when stung by 10-15 bees, local clinical manifestations disappear quite quickly; when stung by 100-200 bees, poisoning develops, and when stung by 400-500 bees, it is accompanied by the risk of developing severe allergic manifestations ( anaphylactic shock ) and the need for emergency assistance.

Allergic manifestations can occur from the bite of almost any insect, but most often severe allergic consequences are caused by the bite/sting of Hymenoptera - hornets, bumblebees, bees and wasps. With an immediate immune response, the victim’s body produces specific IgE immunoglobulins for a specific type of insect allergen. And in such cases, symptoms after a bite appear within the first 10-20 minutes. With the immunocomplex type of reactions, IgG is produced and circulating immune complexes are formed, and symptoms appear much later.

We should not forget that many insects are carriers of dangerous infectious diseases: malaria (malarial mosquitoes); relapsing fever (lice), sleeping sickness (tsetse flies); bubonic plague (fleas); leishmaniasis (mosquitoes); tick-borne encephalitis / Lyme disease (ixodid ticks); tularemia (moose lice); typhus / dysentery (flies), etc.

What insect bites look like: photo of who bit

It is often difficult for a person who does not have special knowledge to determine who bit him or who bit another person. Traces of insect bites on human skin, despite certain general manifestations (swelling and redness/pain at the site of the bite, swelling), also have their own specific features. Below are photos of some insect bites.

Bee sting, tick bite, bug bite

Flea bite, mosquito bite, ant bites

Based on external signs/severity of consequences, insect bites can be divided into three groups:

• The first group is inconspicuous, single light bites that practically do not bother a person (forest ants/single small midge bites). After them, just dots/small redness remain on the skin.
• The second group is relatively mild, but numerous and more pronounced insect bites (numerous flea, mosquito, bedbug and lice bites). The moment of the attack is almost invisible, but external manifestations are more pronounced (severe itching, local allergic reactions).
• The third group is bites that cause pronounced local skin lesions - a large red spot, severe pain, a water bubble at the site of the bite, a tumor with the possible development of edema, local/general allergic reactions, including anaphylactic shock. This can be manifested by the bites of such insects as wasps, hornets, gadflies, bees, tropical ants, large horseflies, etc. Such bites are dangerous and in some cases can pose a threat to human life.

Tick ​​bite

The bite itself is unpleasant, but not dangerous. The tick feeds on blood, and over many years of evolution it has learned to move around the body unnoticed and secrete an anesthetic when bitten. Therefore, we do not feel the puncture of the tick. They are dangerous because, migrating from one warm-blooded animal to another, they carry with them many pathogens. Encephalitis, Lyme disease or borreliosis are very dangerous. Your actions if you are bitten by a tick are here.

Pathogenesis

The venom that enters the body during a sting/bite contains a large number of biologically active components that contribute to the development of a cascade of local and general pathological reactions. The pathogenetic effect depends directly on the type of insect venom. Thus, phospholipase A , wasps and hornets has a hemolyzing effect, causing the breakdown of red blood cells.

The neurotoxin apamin has an effect on the bulbar centers/spinal cord and can depress the respiratory center. Melittin increases the permeability of blood vessels, which contributes to the development of edema, seizures, and coronary disorders. Bites of certain insects are accompanied by a high risk of developing allergies, which is caused by the ingestion of biologically active substances into the body. These are local reactions in the bite/sting area in the form of increased permeability/dilation of blood vessels, irritation of pain receptors, the toxic effect of a specific type of poison, and the allergic reaction itself, which can occur in types I, III, IV:

• Type I (anaphylactic reactions). Develop in 95% of patients after a sting, much less often with bites from blood-sucking insects/contact with parts of dead insects within 1 hour. Allergic rhinitis , urticaria , bronchial asthma , Quincke's edema , and anaphylactic shock occur in this type .
• Type III (immune complex reactions), which develop primarily from bites by blood-sucking insects (bugs, mosquitoes, mosquitoes) and are caused by the formation of immune complexes. Clinically manifests as serum sickness with vasculitis/arthritis and local reactions
• Type IV (slow T-cell reactions). They manifest themselves mainly through bites by blood-sucking insects/contact with waste products of insects. The leading role in the development of such reactions is played by sensitized T-lymphocytes. They manifest themselves as infiltrates on the skin and contact dermatitis.

The routes of sensitization for insect allergies are different: most often it is the parenteral route (sting/bite), less often - contact, aerogenic (through inhalation of house dust containing insect excrement/particles), nutritional (food intake).

Kozheed beetle: species specifics, lifestyle

One of the smallest and yet most common pests in the home are leather beetles. The average body length of insects is from 1.3 to 12 mm, the shape is oval or almost round, the shell covers are covered with small hairs. The dark brown or black color of the shell allows insects to remain unnoticed on dark surfaces, in secluded places under furniture.

Kozher beetle

Covered with many long hairs, the larvae have a spindle-shaped body; sometimes a particularly large tuft of hair forms a kind of brush-tail.

The development of a new generation of insects begins in May after the beetles mate. In the same month, females lay eggs, taking care of their future offspring; they lay them in places where the larva will find a sufficient amount of food, which it needs for growth and development. It is interesting that adult individuals feed mainly on plant sap, but the larva, which must survive 5-6 molts before becoming an adult, needs a different diet - dry substances of plant or animal origin. Woolen carpets (there is a special type of carpet beetle), zoological and plant collections that are poorly cared for, as well as dry food supplies can be excellent food for the larvae.

Classification

Based on the method by which poisons/allergens enter the human body, insects can be divided into two groups:

• stinging (wasps, hornets, bees, bumblebees, ants, etc.);
• non-stinging (biting/blood-sucking) - cockroaches; locusts, mosquitoes, flies; grasshoppers, mayfly, beetles; fleas; moose lice, mosquitoes, mosquitoes, horse flies, midges, etc.

Insect bites are divided into:

• by their type (bee, mosquito, wasp, gadfly, flea, hornet, and so on);
• by type of reaction to them (toxic, allergic).

According to the severity of the lesion, they are distinguished:

• Light flow. Characterized by the appearance of predominantly local signs. Develops against the background of the bite of one/several insects, the venom of which has a moderately toxic ability. As a rule, it does not require medical attention, with the exception of children under 3 years of age.
• Moderate weight. Manifests itself with local/moderate systemic symptoms caused primarily by the neurotoxic effect of the toxicant ( urticaria , Quincke's edema without manifestations from the respiratory tract). Disturbances from the nervous system develop from the bites of several dozen stinging insects, and a hypersensitivity reaction occurs regardless of the number of stings/bites.
• Severe course (severe toxic reactions, anaphylactic shock , angioedema with damage to the central nervous system and hemolysis of red blood cells). They usually develop against the background of multiple bites.

Useful tips

If bites appear on the body, you should use a number of rules. For example:

• First of all, you need to determine what kind of insect bit you, since some bites indicate the presence of parasites in the house, with which you need to immediately begin fighting.
• The bite site should be immediately treated with a disinfectant and, if necessary, the sting should be removed.
• A cold source, possibly ice, is applied to the bite site.
• The bite site is treated with ointment, cream or gel to relieve severe itching.
• Take an antihistamine if you are prone to allergies.
• In difficult situations, you should not hesitate, but call an ambulance immediately.

If you discover fleas, bedbugs or wasp nests in your home, you must immediately take measures to destroy them. This can be done independently, as well as with the help of special services. After this, you need to think about how to protect your home from repeated insect infestations. Plants with a bright aroma that can repel insects are suitable for this. Adhesive tapes, fumigators, various traps, mosquito nets, repellents, etc. are also used.

Causes

Bites/stings in the vast majority of cases are caused by provocative actions of the insect by humans. Essentially, biting is a way of defending/repelling an opponent. A number of insects attack humans for the purpose of reproduction (cutaneous gadfly, which lays larvae on the skin, which subsequently penetrate into tissues). Some types of insects bite humans for food.

Risk factors include frequent/long stay of people in suburban areas in the spring and autumn. Particularly at risk are persons who commit insect bites in high-risk areas without personal protective equipment (mosquito nets, thick fabric clothing, special shoes, pre-treatment with a dissectant).

Risk factors include staying in a suburban area in summer, spring and autumn. People who often go on trips to the forest, lakes, ponds, swamps, without using protective equipment (clothing made of thick fabric, special shoes, mosquito nets) are especially at risk.

What insects can live in bed?

What other insects, besides parasitic bedbugs, can appear in bed? Jumping fleas and linen lice, which have become increasingly common in apartments with unsatisfactory sanitary conditions, can disturb a person’s peace. Cockroaches do not live in beds, but they can build a nest not far from the sleeping area. In very rare cases they attack people. This happens if the Prussians cannot find food for a long time. In search of a safe place, they crawl into the nose and ear canals.

Bed insects include not only ectoparasites. Some individuals are simply looking for a safe place with comfortable conditions. For example, you can often see ants near the bed trying to find food. The likelihood of such an event is especially high if sweet tea is regularly left on the bedside table near the bed, and food crumbs are left on the mattress and pillow.

Symptoms

Single insect bites are manifested by local symptoms in the form of pain that occurs immediately after the bite/sting. Some of the insects bite in bed at night. At the same time, a sleeping person does not feel the bites and finds them only on the body and especially often on the legs after sleep. But in most cases, traces of insect bites on human skin are visually identified in the form of small dots, a blister or a protruding sting. On average, after 15-30 minutes, swelling and hyperemia (redness) develop on the skin at the site of the bite/sting. Later itching appears. Usually, swelling and redness from single bites go away on their own within 24-48 hours, however, the resulting papule often persists for 7-10 days and it often itches. When poison gets under the mucous membranes, severe swelling develops. lacrimation , conjunctivitis , and blepharitis can develop .

With a larger number of bites, pronounced general toxic manifestations develop in the form of chills , dizziness , general weakness , and, less commonly , shortness of breath cramps . General toxic effects may persist for several days. With multiple bites, acute symptoms are observed, including nausea, vomiting, fever, headache, and diarrhea. The development of coma/collapse is relatively rare; death occurs mainly from paralysis of the respiratory center. Particularly severe intoxication develops when bitten by webbed insects (bees/wasps in the area of ​​the tongue and pharynx, which is manifested by swelling of the pharynx/larynx with the threat of asphyxia for the victim). Possible depression of consciousness/ vascular collapse , fibrillatory spasms of skeletal muscles, vomiting, pain in the heart, massive hemolysis , weakened respiratory function.

Allergic manifestations from insect bites can be local, the manifestations of which are limited to the site of the sting/bite; organ, in which dysfunction of target organs appears, and systemic, affecting the functioning of the whole organism. A local allergic reaction is characterized by the appearance of a local area of ​​redness (large red spot) 7-10 centimeters in diameter and swelling, accompanied by itching. a papular rash , blisters , and areas of necrosis may appear at the site of the bite . Scratching can cause infection.

Organ manifestations of an allergic reaction are rare and are manifested by the development of vasculitis , damage to the joints, heart muscle, brain tissue, kidneys, and peripheral nervous system. With direct contact with insect excrement/bodies, symptoms of bronchospasm and rhinoconjunctivitis .

Systemic allergies to insect bites can be mild (anxiety, widespread rash, itching), severe (dyspepsia, dizziness, chest pain/intestinal pain) and severe, manifested by hoarseness, severe shortness of breath, suffocation, severe fear of death, stupor. Less commonly, after a bite, a severe anaphylactic reaction develops with a sharp drop in blood pressure, the appearance of stupor/coma, respiratory/cardiac arrest, which requires urgent assistance, and in its absence ends in death.

Multiple insect bites are especially difficult for older people, especially those with hepatic-renal failure / diabetes mellitus , blood diseases, as well as those with increased sensitivity to the histamine-like/neurotoxic effects of the poison.

Organ manifestations of allergies are quite rare and are characterized by the development of vascular inflammation such as vasculitis , damage to the heart muscle, kidney tissue, brain, joints, peripheral nervous system and the appearance of symptoms found in these diseases. Direct contact with the bodies of insects and their excrement sometimes leads to symptoms of rhinoconjunctivitis , stomatitis , bronchospasm , and dyspepsia .

Lice

There are several types of lice - head lice, clothing lice, pubic lice. The latter look like a small crab, are localized on the pubis, are rare - among people leading a depraved lifestyle, homeless people. Clothes live in human underwear, bedding, and bite more often at night. After insect bites, numerous small red spots and minor swelling appear. Head lice are more likely to attack children. They live on the head. They are the most common parasite.

Symptoms of head lice:

• severe itching;
• spots on the skin, inflammation;
• dermatitis from bites with prolonged infection;
• the presence of nits on the hair.

Action must be taken immediately, as insects multiply quickly. They use folk, professional remedies. In the absence of treatment for pediculosis, the development of dermatitis, nervous system disorder, and deterioration in general health are observed.

Tests and diagnostics

The main tasks in making a diagnosis are to establish the fact of an insect bite and determine its type, collecting anamnesis data (presence of allergic reactions in the past upon contact with insects). A clinical examination is carried out to identify/determine the nature of skin lesions and the degree of their severity, the presence of signs of organ/generalized disorders. If necessary, instrumental/laboratory examinations are carried out, including ECG, ultrasound of the abdominal organs, spirography; General/biochemical analysis of blood and urine.

If an allergic reaction develops - allergy tests on the skin with insect allergens, laboratory tests to identify specific immunoglobulins for allergens. Differential diagnosis of an allergic reaction to insect bites is carried out with contact dermatitis , toxic reactions, other allergic reactions ( bronchospastic conditions , urticaria , rhinitis / conjunctivitis , Quincke's edema ).

Prevention

Preventative measures for insect bites/stings include the following recommendations:

• Avoid places with significant concentrations of hymenoptera insects: apiaries, wasp nests, vegetable markets/shops.
• If you get into the area where bees/wasps are present, do not make sudden movements/behave calmly. When going outdoors, do not use scented cosmetics: lotions, soaps, perfumes, cologne, sunscreen, shampoo, as such odors attract insects.
• Do not take bee products/food or drinks outdoors.
• When hiking in nature, use boots and closed clothing made of thick fabric. You must put a hat on your head, and you can tuck your trouser legs into your socks. Don't walk on the grass barefoot. Avoid brightly colored clothing.
• Be careful when working in your garden. Use insect repellents.
• When going outdoors, take a small first aid kit with you (antihistamine, hydrogen peroxide, iodine, dexamethasone ampoule).
• Maintaining housing in proper sanitary and hygienic condition, disinfecting residential/non-residential premises, landfills, garbage cans with chemicals.

Consequences and complications

The consequences of insect bites, almost regardless of their type (the consequences of the bite of scolopendra, bees, wasps, mosquitoes, centipedes, etc.) include:

• Significant local reaction from bites/stings in the facial area ( swelling , painful erythema ), which can cause airway obstruction.
• Development of a purulent skin infection ( pyoderma ) at the site of an insect bite. Less common are cases of erysipelas , cellulitis / abscess at the site of the bite.
• Anaphylactic reaction . Especially in persons sensitized to insect bites.
• Infectious diseases transmitted by insects ( malaria , relapsing fever , sleeping sickness , bubonic plague , leishmaniasis , tick-borne encephalitis , dysentery , Lyme disease , etc.

Bedbug bites

Bedbugs need blood to feed, and they will bite you constantly and intentionally. A feature of bedbug punctures is the location of the bite sites; the bug bites in a line, making 3 to 5 punctures. Some do not notice the bites, while for others the consequences are violent. You can study more here.

Forecast

In the vast majority of cases, insect bites/stings end favorably and without disability. Timely assistance allows the patient’s condition to normalize within 10-30 minutes and eliminates the need for hospitalization. With the development of an allergic reaction to insect bites with a mild/moderate course and timely treatment/adequate medical care, the prognosis is also favorable. The prognosis worsens with the development of severe organ damage and a systemic allergic reaction.

List of sources

• Stanek V.Ya. Illustrated encyclopedia of insects. Prague: Artria; 1977. .
• Safina L.F., Fassakhov R.S., Reshetnikova I.D. Skin manifestations of allergic reactions to stings of hymenoptera insects // Practical Medicine. - 2011. - No. 3, - pp. 140-142.
• Dremova V.P. Urban entomology. Harmful arthropods in the urban environment. — Publishing house “IzdatNaukaServis”. Ekaterinburg. - 2005, 278 p.
• Lawlor G. – Jr., Fischer T., Adelman D Ch. Allergy to insect venoms. in the book Clinical immunology and allergology - M.: Praktika, 2000. pp. 346 – 356.
• Zaikov S.V., Mikhey L.V., Kulik L.G., Allergy to non-stinging insects // News of medicine and pharmacy. - 2010. - No. 345. - p. 36-37.