Some people, suffered an allergic reaction to a bee sting, wasp or other stinging insects in childhood, may suffer a similar allergy for life.
Contrary to popular belief, some children do not get rid of allergic reactions to insect bites. There is an allergy to stings of insects of Hymenoptera order, especially bees (7%), in rare cases – wasps, bees, hornets and ants. It is important the immunogenicity of the replicate.
Bees sting only when they feel anxiety, or when their nest is in danger – they are not “naturally aggressive”. Puncturing the skin of victim, the bee can not retrieve the stinger back, because the stinger has burrs – like a harpoon. After stinging, a bee flies away, leaving a sting venom gland and damaged part of the digestive tract in the victim’s body, so the bee subsequently dies. Wasps and hornets are aggressive by nature, especially in the fall when their food stocks are exhausted. Their sting is not chipping, does not get stuck in the body of the victim, so the wasps and hornets can sting repeatedly. After a bee or a wasp sting there is an itchy pimple on human skin, which normally disappears quickly – this is a normal reaction of the skin to injection of venom. Antigens of poisons of different species are different, for example, there is serotonin in a secret of sting of wasps, a secret of stings of hornets has acetylcholine. In addition, there is a large number of biologically active substances in poisons of females – histamine, norepinephrine, peptides, amino acids.
Allergic reactions can be caused also by inhalation of the secretions of various insects.
When an allergic reaction to an insect bite occurs the first time, it is likely you have pre-sensitization by other allergens, or prior sensitization by unnoticed bite. Such substances as gistaminliberatory may cause local skin reactions in the form of mild redness, swelling, pain, itching. This reaction caused by nonspecific action of some venom components, is short-lived and usually does not require treatment. Reaction to the bite can be toxic, what happens when you are bitten by dozens of insects, it is characterized by general weakness, headache, nausea, vomiting.
Around the world there are hundreds of thousands of species of insects. Compared with this number, the number of allergic reactions caused by them is relatively small, although the significance of the allergy depends not only on the frequency of symptoms as the severity of the forms of pathological processes: people die from allergic reactions 2 times more than from snake bites. Allergic reactions can be caused by:
insect bite, when antigens enter the body;
bite of blood-sucking insects;
flakes or other fragments of the body of live or dead insects that cause sensitization by penetrating into the body through the respiratory tract, rarely by direct contact with the skin.
Non-allergic reactions occur in the connective tissue of the eye and in the genital organs, they are characterized by pain and swelling. More severe local reactions (up to enlarged lymph nodes) may be result of secondary infection. Toxic reactions happens in the case of a large number of insect bites. Symptoms appear within a few hours in the form of edema, headache, vomiting, diarrhea, fever, seizures, stupor, coma. Hundred bees bites at a time can lead to death. However, observations of beekeeper shown that a person can get used to poison of insects.
Allergic reactions occur in various forms, ranging from the local symptoms, with more or less severe manifestations to the shock and death. There are 4 types of systemic reactions.
Mild systemic reactions (31%): generalized urticaria, pruritus, fatigue, anxiety.
Systemic reactions (38%): the symptoms of type 1 and shortness of breath, abdominal pain, nausea, dizziness, vomiting.
Severe form of systemic reactions (20%): previous symptoms and dyspnea, dysphagia, hoarseness, incoherence of thought, a feeling of impending doom.
Shock (11%): in addition to previous symptoms – cyanosis, fall in blood pressure, collapse, defecation, loss of consciousness.
In case of especially severe allergic reaction death can occur within minutes: 66% of deaths are in the first hour after the bite, 96% – in 5 hours. The leading cause of death is asphyxia and then circulatory collapse.
Sensitization process is similar to allergies caused by drugs (although in some cases it is impossible to predict). After preceded anaphylactic positive skin reaction, the manifestation of systemic reactions from repeated bites can be expected in 60% of cases, obviously, it is important the interval between reactions. Repeated bites (in the first years after the first bite) lead to anaphylactic reactions quite often, after 5 years the frequency of their manifestation does not exceed 35%. Approximately 10% of people have a spontaneous desensitization. Reaction becomes weaker after each insect bite. According to statistics, 33% of the people have hypersensitivity to insect bites accompanied by other allergic symptoms, 25% of people have genetically determined hypersensitivity.
Perhaps, in addition to a special form of injection of antigen, other antibodies except reagin, have pathogenetic significance. This is confirmed by the fact that 3% of victims have a syndrome of serum sickness. 3% of people have delayed reaction, which is seen only in a few days: thrombocytopenic purpura disease, nephrotic and hepatorenal syndrome, mono- and polyneuritis, necrotizing vasculitis, cerebral purpura.
Allergic reactions to insect stings are diverse. Clinical manifestations begin after 10-20, sometimes 40 minutes or more after the bite and last for 2-4 hours. The sooner there is a reaction, the harder it is. The speed of appearance and increase of symptoms are directly proportional to the severity of the disease: manifestations, developing after 1-2 minutes after the bite, in 40% of cases are fatal.
In case of local allergic reaction, the swelling and redness quickly spread around the bite, growing and reaching a maximum during 3-4 hours, sometimes days, accompanied by severe itching. Usually redness disappears quickly , itching lasts a little longer, and swelling may remain for several days.
Limited local reaction, however, can be fatal in case of bites in the mouth, pharynx, or larynx, generalized reaction is in the form of hives, often with angioedema in different parts of the body without reducing blood pressure, asthma, laryngeal edema, but often with gastrointestinal symptoms. Life-threatening anaphylactic reaction to a sting is characterized by an immediate drop in blood pressure, bronchospasm, and (or) laryngeal edema, itching of the throat, difficulty in breathing and swallowing, abdominal pain, vomiting, nausea, diarrhea. The causes of death are suffocation from swelling of anatomical airway, their obstruction as a result of increased secretion into the lumen of the bronchi or collapse. Older people die more often.
Additionally, Hymenoptera venom can cause immune disease, occurring on immune-type with production of IgG and IgM and various cytokines. Insect bites and anaphylactic reactions occur usually in the summer. The greatest number is in July, August and early September. Bites are most often are in the neck and head.
Basic principles of treatment of people with allergy to the venom of stinging insects are similar to those in the treatment of other allergic diseases: preventive measures, symptomatic treatment, where antihistamines and immunotherapy have the leading role. Fate of person often depends on measures, which have been taken in the first hour after the bite. The earlier an allergic reaction, the more dangerous it is. Possible medical care in such cases is usually quite limited, as an insect bite happens mainly in the nature (in the forest, field, etc.). In any case, we recommend to gently suck the poison from the wound, although this method does not ensure the complete removal of antigens from the body. If a bee stings, it is necessary to remove the sting from the wound, avoiding extrusion of remaining poison. The spread of venom can be stopped by a tourniquet above the wound in case of bite in the leg or arm. Individuals with increased risk of severe allergy to insect stings should always carry a first aid kit (tow, syringes with needles, epinephrine, antihistamines and corticosteroids for injection). Do not expect a manifestation of the reaction, it is necessary to act immediately (make injections of 0.3 mg of epinephrine in the bite place and subcutaneously in another part of the body). However, injections, conducted by people with no special skills, can be dangerous. Other medications in urgent cases are less effective, for example, isoprenaline, which is recommended to put under the tongue.
People, who have already the general reactions and antibodies of class Es need desensitization. Pronounced local symptoms may be precursors of the general reaction, but not all authors recommend to make desensitization. It is not needed in case of the absence of antibody of class E.