A severe allergy to insect bites is a problem that affects so many people. Significantly complicating the fight against it is that the body's high sensitivity to bites persists for life, and in many cases allergy manifestations can increase from one bite to the next.
Often a person has a hereditary predisposition to allergies. An unfavorable ecological situation, the growing isolation of a person (especially a child) from nature, as well as some diseases, increase this heightened sensitivity to various substances, thereby increasing the likelihood of a pronounced allergic reaction to the bite of virtually any insect.
On a note
Poisons, saliva and other insect secretions are considered to be strong allergens. Sometimes even the airborne chitinous hairs, pieces of external covers and excrement of insects can cause a dangerous allergic reaction.
However, most cases of the most severe allergies are observed after bites by Hymenoptera insects. In 7% of cases, these are bees, somewhat less often - wasps, hornets, bumblebees and tropical ants. Much less often the body reacts heavily to bites of mosquitoes, midges, fleas, bedbugs and other non-stinging insects.
The photo shows an example of a pronounced allergic reaction to a hornet bite:
The aggressive effect of the poison of Hymenoptera insects is due to the characteristics of the constituent components. For example, the bee venom contains the following substances:
- Melitin - this compound actively destroys erythrocytes, causes acute inflammation, muscle spasm and tissue metabolism, reduces blood coagulation.
- Apamin - this protein has a significant similarity with the neurotoxins of snake and scorpion poisons, greatly excites the structures of the nervous system.
- Hyaluronidase - helps the poison spread throughout the body.
- Phospholipase A - enhances the inflammatory process and stimulates the hemolysis of erythrocytes.
- Histamine - dilates blood vessels, provokes the onset of inflammation.
In addition, a particular protein entering the bee venom causes the mast cells in the affected tissues to release their own histamine, which is the main activator of allergic processes.
Poison wasps is characterized by the presence of the substance of kinin, which causes vasodilation, contraction of smooth muscles and provokes acute inflammation. And in the poison of various types of hornets also contains acetylcholine, which slows the heart rate, lowers blood pressure, reduces the muscles of the bronchi and increases the secretion of the bronchial glands.
On a note
Throughout the world, from allergic reactions to insect bites, three times more people die than from snake bites, and a person can die from a single bite.
The reaction to the bites of bloodsucking insects - bugs, fleas, mosquitoes, etc. - is due to the presence in their saliva of specific enzymes that cause allergies (for example, substances that prevent rapid blood clotting). In addition, the flea, for example, often literally bites into the skin almost with the head, adding to the wound additional irritants.
The photo below shows the flea at the time of the bite:
The saliva of adults of bed bugs contains an analgesic, as a result of which their bites are almost painless and usually show up only in the morning. Also in the saliva of blood-sucking insects, there are sometimes pathogens of very dangerous diseases: malaria, plague, tularemia, hepatitis B, anthrax and others.
Symptoms and forms of an allergic reaction to insect bites
The strength of the allergic reaction of the body depends on the amount and degree of aggressiveness of the administered allergen, as well as on the number of antibodies corresponding to it, circulating in the human blood. From the bite to the bite of insects of the same species, the antibody titer (that is, their concentration) can increase. Accordingly, the strength of the body's response will increase.
After an insect bite, an allergic reaction sometimes occurs instantly, and sometimes occurs only for several tens of minutes, occasionally hours. If there is no sensitization to the allergen, then in the area of damage the skin reddens, swells, itching appears. These symptoms, as a rule, last for a short time and completely disappear. But in the presence of sensitization the body reacts much more strongly, and this reaction by local manifestations is no longer limited.
Photo of an allergic reaction to a bee sting:
Thus, the symptoms of an allergy to insect bites can vary greatly in nature and severity. For example, the symptoms can be:
- Local - burning pain, swelling of the skin, swelling or tightness, flushing, itching, rashes;
- Generalized - urticaria, conjunctivitis, rhinitis, weakness, fever with chills or without, dizziness, difficulty breathing, lowering blood pressure, frequent pulse of weak filling, heart pain, fainting.
Also, such life-threatening conditions as Quincke's edema and anaphylactic shock can also be observed.
The photo shows an example of Quincke's edema:
Rash from insect bites can also vary significantly in intensity, appearance and localization. It can represent blisters, nodules, erythematous spots, erosion and other variations. In difficult cases, there is a hemorrhagic, bullous, necrotic rash.
When combing through damaged skin, an infection can penetrate. In this case, the skin elements are transformed into pustules (pustules), and sometimes into long-healing ulcers.
Allergy from insect bites can be masked by other allergic reactions, as skin rashes may be similar at the same time. Therefore, in each case, you need to try to find out what exactly caused the rash.
Child's allergy: how dangerous is this?
Often children react to the effect of the allergen more strongly and longer than adults (although in some cases the situation is the opposite). Stains from insect bites in them can persist for several days.
Often, the bites of insects are badly scratched: because of the constant itching the child sometimes combs the skin to the blood with the risk of bringing an infection, which may pose an additional danger to health.
"Last year we had a terrible situation in the summer. We got to Crimea for a week, in Olenevka, and there Sasha was bitten by a wasp. He says it's big and thin. I thought he was fooling around, because in general he was a quiet boy and even if he was hurt, he would not yell. Immediately he was bluish with a cry, we could not hold him, there was an impression that he had some convulsions. An eerie sight. The arm was swelled at once, and so that he could not bend it. The rash has appeared, on the back the face has thrown also. A child at the same time still waving and shouts. Well, the clinic was open. We took him for a while - about twenty minutes, probably passed, he had a faint, the temperature had risen. Doctors chopped something, prescribed a dropper, said that the child had anaphylactic shock and if we stayed, we could not take him. I later found out what these wasps were like. They say that the roads are called brown and big, and the bite is the most painful. As a result, we were forced to stay in the Crimea for a week, because only five days later Sasha was released from the medical center. "
Below in the photo there is an example of a strong irritation from insect bites in a child:
With a high sensitization to the venom of Hymenoptera, a child can develop a complicated reaction in the form of an angioedema and anaphylactic shock after a bite. This point should always be borne in mind: when urticaria or other severe skin manifestations occur after an insect bite, and when general symptoms of an allergy occur, it is necessary to urgently consult a doctor. Self-medication in this case it is better not to deal with, because many drugs have limitations for use in childhood.
What is dangerous acute form of allergy?
Urticaria, which arose after insect bites, is not the most severe variant of allergy manifestation. Much more dangerous are the symptoms of general intoxication, a sharp drop in blood pressure, choking and collapse - all of which can pose a threat to human life.
The most dangerous complications of allergy are anaphylactic shock and Quincke's edema.
Quincke's edema, or, in other words, giant urticaria, is an acute and extensive swelling of tissues with well-developed subcutaneous fat. Such edema can be caused by a powerful release into the blood of biologically active substances that cause vasodilation and increase their permeability.
Very dangerous swelling of the larynx and tongue - in this case, the risk of asphyxia is high, a person may die from suffocation. Also, cerebral edema is a high risk, as a result of which neurological symptoms may appear: convulsions and paralysis. With these severe reactions to insect bites for the treatment of allergies, the patient should be hospitalized urgently.
The photo below shows the swelling of Quincke:
Anaphylactic shock, sometimes also developing after insect bites, arises from the violation of peripheral and central blood circulation under the influence of biologically active substances that are released into the blood in large quantities (in particular serotonin).
The victim becomes restless. He has shortness of breath, urination is disturbed, confusion arises. The skin becomes cold, cyanotic and moist. Nausea, vomiting, and diarrhea may occur.
In the case of developing anaphylactic shock, skin irritation that occurs after an insect bite is usually pronounced, accompanied by severe pain and increased edema. Local itching quickly spreads over a large area of the body. Often, the laryngeal edema, broncho- and laryngospasm, arterial pressure falls. Without adequate treatment, a person can die within a few minutes or hours of suffocation and the associated vascular collapse.
Antiallergic drugs against insect bites
Antiallergic drugs used after insect bites can be divided into the following groups:
- Antihistamine or, in other words, blockers of H1-receptors: 1st generation - Dimedrol, Diprazin, Suprastin, Tavegil, Diazolinum, 2nd generation - Astemizol, Terfenadine, III-rd generation - Loratadin (Claritin), Azelastine.
- Stabilizers of mast cells: Nedocromil, Ketotifen, Intal.
- Glucocorticoids: Prednisolone, Hydrocortisone, Betamethasone.
- Symptomatic means: adrenaline, Salbutamol, Fenoterol.
Of antihistamines with insect bites, more drugs of a new generation (II and III) are more often prescribed today. They do not have cardiotoxic and hepatotoxic effect, they do not inhibit the central nervous system, the duration of their action is longer.
Widespread use in allergies, including biting insects, was Claritin. However, it is worth noting that in some cases it is justified the appointment and preparations of the I-generation, which do not last long, but their action is faster.
When taking any medications, including Diazolin, Suprastin, Diphenhydramine, etc., it must be remembered that the medicinal substances themselves are capable in rare cases to cause allergic reactions, right up to the Quincke's edema.
In folk medicine, for the removal of irritation that occurs after insect bites, tincture of marigold, onion, plantain and lemon juice, as well as a solution of drinking soda, is used. From mosquito bites used tincture of the lakonose, the grass of the lice.
Repellent insects are essential oils of cloves, anise, eucalyptus and basil.
Hydrocortisone and other glucocorticosteroids, used topically, for example, as an ointment, will help cure local inflammation with insect bites.
First aid for the development of an allergy to an insect bite
When biting stinging insects (wasps, hornets, bees), you should immediately give the person first aid, without waiting for the appearance of signs of allergy.
Sometimes it seems to the victim that nothing terrible has happened - think, the wasp (or bee) has bitten. And more often than not anything terrible is not happening. However, sometimes an allergic reaction develops so rapidly that the count can go on for a minute.
When biting a bee, it is necessary to remove the stinger as soon as possible with tweezers, since the sac with the poison continues to contract and inject the poison under the skin. In case of bites of wasps and hornets, the stinger should not be looked for - these insects do not leave it in the wound and can sting repeatedly.
Not later than 1 minute from the moment of a bite, poisoning from the wound can be effective (it should not be done for long, and not more than 1 minute, necessarily spitting).
Then you need to slow the rate of absorption of poison into the blood, and also help reduce local allergic swelling from an insect bite. To do this, a cold should be applied to the bite site, for example, an ice pack.
If a person is inclined to a strong allergy to insect bites, he knows about it, but it so happens that he does not have an autoinjector with adrenaline (usually allergy sufferers always carry it with him), then additional measures will be useful. When you bite in the leg or arm, the tourniquet is put on the tourniquet - this will allow you to gain time, and the poison can not spread through the body with blood flow. Urgently call an ambulance.
Itching and rash after an insect bite help to reduce special preparations: it can be sprays and ointments containing panthenol, Fenistil gel, hormones like Advantan and Hydrocortisone, special balsams from insect bites for children from the Gardex and Mosquitall series.
When providing first aid, do not:
- Drink alcohol - to avoid the expansion of blood vessels and accelerate the absorption of poison into the blood.
- Cool the affected area when the bite is damp earth or clay - so you can make an infection, including getting a life-threatening tetanus.
- Trying to squeeze poison out of the wound - such a massage will only provoke an accelerated spread of poison into neighboring tissues.
- Apply Diprazin and other H1-histamine blockers of the first generation in severe allergic reactions. They are ineffective in relation to histamine, but they can sharply lower blood pressure, which will further exacerbate the situation.
What to do with serious consequences?
Treatment of complicated allergic reactions should be performed by a doctor.
At the pre-hospital stage for the treatment of acute laryngeal stenosis, normalization of blood pressure, inhalation of glucocorticosteroids through the nebulizer (0.25 mg Budesonide with compensated stage of stenosis, 0.5 mg with subcompensated, 1 mg with stenosis of the third degree larynx) is used. The maximum number of inhalations is 3 with an interval of 20 minutes.
Suprastin for complications after insect bites is used with ineffective inhalation therapy or in the absence of a nebulizer - intramuscularly or orally (with compensated stenosis). Systemic glucocorticoids (prednisolone) are administered intravenously, adrenaline is administered subcutaneously.
To remove the attack of asthma, you can use Berodual, Salbutamol - through an inhaler or nebulizer.
It should be remembered that when the insect bites the first signs of severe allergy, the injured person should be taken to the hospital as soon as possible (also you should consult by phone how to help a person). If there is no experience in providing first aid to others, the victim should be put on his back, placing a platen of clothes under his head, providing a drink and not giving medicines, in whose actions there is no full certainty. In many cases of acute allergy, it is the unprofessional actions of voluntary assistants that contribute to the aggravation of the situation, and therefore the best thing that can be done is to deliver the person to the doctor as soon as possible.