Bite of a spider, "tarantula", "black widow"

The article was prepared by a specialist for informational purposes only. We urge you not to self-medicate. When the first symptoms appear, consult a doctor.

The danger of a spider bite depends on various factors. The clinical manifestations of this condition are determined by the immune abilities of the human body and the poisonous properties of a particular type of spider. The dependence is this: the more poisonous the spider, the more dangerous its bite, even for a person with perfect immunity. And, conversely, the stronger the immune response, the greater the likelihood of a relatively mild course of any bites.

Cross spider bite

The most common spider on all continents is the cross spider. Its name is due to the appearance of this arthropod. It is easy to recognize the cross breed by the characteristic white dots on its back that form a cross. The size of these spiders is not very large, although they can reach 2 cm without taking into account the spread of the legs. The cross does not attack a person purposefully. Usually, bites happen by accident when a person falls into its web, where it waits for its victim.

The bite of the cross spider is not dangerous to humans. Clinical manifestations are limited to local reactions in the form of redness of the skin, local swelling and painful reddened hardness, accompanied by a burning sensation. Rarely, general reactions such as a short-term increase in body temperature and mild chills may occur. This is possible if hemolysins and other toxins enter the systemic circulation of a person with an unstable immune response.

In typical cases, all manifestations go away on their own within a few days. If this does not happen, it is advisable to apply cold to the bite site, lubricate it with alcohol or anti-inflammatory ointments (kremgen, sinaflan). Under no circumstances should you scratch the bite site. This can cause an infection to enter the skin with the development of a purulent process.

Population and species status

The cross spider lives over vast territories, inhabiting almost the entire territory of Eurasia, as well as the territory of North America. Cross spiders are grouped into a large number of subspecies that live either in large spaces or in limited areas. If you take the Hawaiian wolf spider, it is found in a limited area of Cautan Island.

The spider, called the striped hunter, is found throughout the vastness of modern Europe. To date, there are no programs or efforts related to the conservation and increase in the total number of such arthropods.

Cross spiders, along with many inhabitants of our Planet, are part of the global ecosystem of wildlife. Many people argue that if a living creature is poisonous, then it has no place near a person. This opinion appears in people as a result of lack of education or as a result of various phobias. They are frightened even by the simple word “spider,” not to mention the sight of a live spider.

In fact, you need to understand that the destruction (disappearance) of one of the chains of our ecosystem can lead to unpredictable consequences.

Tarantula spider bite

The tarantula spider has become a kind of indoor pet for many lovers of this type of arthropod. Usually, this is a fairly friendly animal towards humans, which is even able to recognize its owner. Therefore, a person is extremely rarely exposed to its attacks. If this happens, it is only for the purpose of self-defense, when the spider feels danger. The most interesting thing is that when a tarantula bites a person, it does this without releasing poison, but only causing mechanical superficial damage to the skin in the form of a small scratch. In natural conditions, it hunts small animals, frogs, lizards and small birds. The peculiarity of its poison is its high neurotoxic properties, as a result of which the victim is paralyzed, but alive.

The bite of a tarantula spider is absolutely safe for humans. The only thing you need to be afraid of is infection of the bite wound when scratching with dirty hands. To prevent this from happening, the damaged area is treated with any antiseptic solution and covered with a dry, clean bandage for several hours. Once a small crust has formed, there is no danger at all. Occasionally, slight redness of the skin may occur, accompanied by itching.

Nutrition

The living creatures described are carnivorous. In addition to the flies and mosquitoes already mentioned, aphids, various midges and other small representatives of the insect world can become their prey. If such a prey falls into the net of a given predator, then he has the opportunity to feast on it immediately.

But, if he is full, he is able to leave food for later, entangled with a thin adhesive thread. By the way, the composition of such a “rope” is somewhat different than the thread of a spider’s web. Further, the spider hides its food supply in any secluded place, for example, in the foliage. And he eats it when he feels hungry again.

These spiders have a very excellent appetite. And their bodies require a lot of food. The daily norm is so high that it is approximately equal to their own weight. Such needs force the described representatives of the animal world to work accordingly.

Cross hunters, lying in wait for prey, sit in ambush with virtually no rest, but even if they are distracted from business, it is for a very short time.

These creatures digest their food in an extremely interesting way. This happens not inside the body, but outside. The spider simply releases a portion of digestive juice into the body of the victim, wrapped in a cocoon. In this way it is processed, turning into a substance suitable for consumption. Next, this nutrient solution is simply drunk by the spider.

It happens that the nets placed by these eight-legged creatures catch prey that is too large for such a baby to handle. The spider tries to get rid of such problems by deliberately cutting off the threads of the network connecting itself.

But if the threat does not stop there, for the purpose of self-defense he is quite capable of successfully using his chelicerae against what are, from his point of view, huge creatures. For example, a frog a quarter of an hour after its bite may be completely immobilized.

But are cross spiders dangerous for humans or not ? Actually, the poison of these creatures does not produce irreversible changes on the body of all vertebrates. On people, due to the small amount of toxic substances produced by these arachnids compared to human size, they are not able to have a serious effect. The bitten subject feels only mild pain, which subsides fairly quickly.

Black widow spider bite

A female karakurt spider is called a black widow. It is not for nothing that she got her name, because her victim is not only the male after mating, whom she kills, but also a person. The black widow is the most common species of venomous spider on all continents. Its favorite habitat is secluded corners in places where dry firewood is stored, basements and sheds, and other dry places under the roof. This type of arthropod is very aggressive. Any attempts to approach her web cause a lightning attack. You can recognize a black widow by the following characteristics: a relatively small body (1 cm) of black color with a wide spread of legs (about 4-5 cm). A characteristic sign is a red dot on the abdomen. The peak of aggressiveness occurs in the summer.

The black widow has one of the most toxic venoms of all arachnids. Its main components are neurotoxin and hemolysin, which have high toxic abilities and antigenic properties. This is the basis for the development of a rather vivid clinical picture after a bite, which grows at lightning speed.

Clinically, it looks like this:

The immediate moment of a bite is felt by a person as a sudden sharp prick;
A small dot appears at the site of the bite;
Some time passes between the onset of symptoms and the bite (1-2 hours) like a light interval;
Relatively mild pain at the site of the bite, which is caused by the destruction of nerve endings by the neurotoxin;
Rapid entry and distribution of toxic components of black widow venom throughout the body due to the aggressiveness of hemolysin and blood thinning;
The appearance of blue or darkening of the skin around the bite, which can become widespread;
General temperature reaction with a sudden jump in temperature to critical levels;
Stupefaction of varying degrees (from fainting and lethargy to cerebral coma);
Widespread muscle pain and spasm;
Convulsive syndrome, both local and widespread;
Rashes in the form of small hemorrhages throughout the body;
Falling blood pressure and strong, rapid heartbeat;
Nausea and vomiting accompanied by severe headache;
Heavy sweating and drooling;

Typically, these symptoms have a wave-like course, periodically subsiding and exacerbating again. Therefore, it is imperative to seek medical help in case of the slightest suspicion of a black widow bite. Treatment should be carried out in a hospital setting or even an intensive care unit.

The most effective method is considered to be the introduction of a specific antitoxic serum, which is not available in all medical institutions. If it is not possible to use it, pathogenetic treatment is carried out aimed at reducing symptoms and removing toxins from the systemic bloodstream. For this purpose, patients are administered solutions of calcium chloride or gluconate, anticonvulsants (diazepam, sibazon), massive infusions and diuretics. Constant monitoring of basic vital parameters is carried out.

Description and features

Spiders are very interesting representatives of the biological kingdom, and some of them are far from harmless. They also have an amazing structure. Some varieties of these creatures have special appendages in their mouths, the so-called jaw claws.

These include araneomorphic spiders - members of a large group of arachnids. These natural adaptations are called chelicerae. They allow these creatures to successfully attack prey that is quite large in comparison with their size, which gives them the opportunity to win the evolutionary race.

The cross spider is one of these creatures - a striking specimen from the orb-weaver family.

This creature earned its name not by chance, but because of a very noticeable feature - a mark on the upper side of the body in the shape of a cross, made up of white, in some cases light brown, spots.

The spider got its name from the color on its body that resembles a cross.

This appearance feature turns out to be very useful for these biological organisms. This gift of nature is a sign that can scare away many hostile living beings. The remaining characteristic features are clearly visible in the photo of the cross spider .

As you can see, it has a rounded body. It turns out to be almost integral with the head, dividing into two areas, which are usually called the cephalothorax and abdomen.

The size of such living creatures cannot be considered too large. For example, females, which are more impressive in size than males, are usually no larger than 26 mm, but there are specimens of such spiders that are only a centimeter long and much shorter in length.

In addition, the cross is endowed with eight sensitive flexible legs. He also has four, paired, eyes. These organs are located diversified, which allows this animal to have a 360-degree view in all directions. However, these biological organisms cannot boast of particularly acute colorful vision.

They distinguish only the outlines of objects and objects in the form of shadows. But they have quite good senses of taste and smell. And the hairs covering their body and legs perfectly capture a wide variety of vibrations and vibrations.

Chitin, a special natural binding compound, serves as the covering of the body and at the same time a kind of skeleton for such creatures. From time to time it is shed by these arachnids, replacing it with another natural shell, and during such periods the growth of the organism takes place, freed for a time from the elements that constrain it.

The cross spider is considered a poisonous spider, but its poison is not dangerous for people

This representative of the biological kingdom of arachnids is capable of secreting a substance that is toxic to all types of organisms. So is the cross spider poisonous or not ? Without a doubt, this small creature is dangerous to many living things, especially invertebrates.

And the poison they secrete has an extremely detrimental effect on their neuromuscular organization.

House spider bite

There are several varieties of house spiders: gray, brown, black and others, which is determined by their color. The most common representative is the black house spider. Its favorite habitats are indoor parts, as well as outdoor areas with good lighting and dry conditions. This could be wooden window frames under the roof, cracks in wooden logs, etc. Spiders of this species are quite small and weave webs in small corners, to which humans rarely have anything to do. Therefore, human bites from a house spider are rare.

If such a situation arises, then there is nothing wrong with it. House spider bites are absolutely safe for humans. There is no danger, even for a small child. Typically, symptoms are limited to local manifestations in the form of pain and burning after direct contact of the spider with the skin, a pinpoint bite with redness of the surrounding skin. It is extremely rare to experience a slight increase in body temperature and general malaise. To relieve symptoms, it is enough to apply cold and treat the bite area with an antiseptic. In extreme cases, there is a need to use hormonal ointments and antihistamines.

Treatment

The clinical picture of the action of the spider's venom can go away spontaneously after some time and the victim does not even require hospital treatment. Medical care in the form of supportive care can be effective in mild to moderately severe cases.

Treatment is usually symptomatic with the use of alcohol compresses, painkillers, anti-inflammatory and antihistamine drugs. Patients are recommended to rest in bed, warm their extremities, and drink plenty of fluids. If stool retention or intestinal paresis occurs, enemas can be used in case of urinary retention - bladder catheterization is performed.

The doctors

Medicines

Novocaine is a local anesthetic. Can be used in the form of a solution for infusion or injection in doses determined by your doctor.
Calcium chloride is a drug that can replenish calcium deficiency in the body. A solution of calcium chloride with a magnesium salt, oxalic and fluoric acid forms insoluble compounds, which makes it possible to use it as an antidote.
Diazolin is an antiallergic agent that acts on h2-histamine receptors. The standard daily dose for adults is 100-300 mg.

Procedures and operations

Currently, many antidotes have been isolated to the toxins of various spiders, so the most recommended is the use of serum during the first hour of hospitalization. It should be administered according to the Bezredka method to avoid the development of serum sickness.

Symptoms of spider bites

The general clinical manifestations of spider bites have a certain similarity, regardless of the specific representatives of this class of arthropods. This is determined by the identical qualitative composition of the toxic components of the poison. The main ones are neurotoxin and hemolysin. The first causes damage to the nervous system (peripheral nerves and brain), the second causes the destruction of red blood cells, provoking its severe dilution and direct destruction of blood vessels. Their toxicity to the human body depends on the concentration of these two toxins in the venom of different types of spiders.

Based on the data provided, you can determine the possible symptoms of spider bites. These include:

Local changes in the area of the bite always develop primarily. They are represented by varying degrees of severity of skin redness, pain, swelling and burning. The more pronounced these symptoms are, the more poisonous the spider is. In severe cases, darkening occurs with widespread necrosis (death) around the bite;
Skin rashes all over the body. Usually the rash is of a pinpoint hemorrhagic nature, similar to small hemorrhages. Localized on the limbs and torso;
General temperature reaction in the form of hyperthermia from 37°C to 40°C with chills;
Headaches and confusion;
Frequent heartbeat and difficulty breathing, surges in blood pressure;
Pain in the chest and abdomen;
Muscle pain and spasms, even cramps;

Pathogenesis

The pathogenesis is based on the toxic effect of poisons - neurotoxic and necrotic (cytolytic), as well as the development of allergic and infectious reactions in response to a bite. Effects may be local only or with additional systemic reactions resulting from neurotoxicity.

The effect of spider venoms resembles strychnine, but is much weaker. After excitement, a loss of strength occurs and paralysis is possible. The toxic complex biochemical mixture contains neurotoxic substances that paralyze the nervous system, as well as hemolytic substances that destroy the blood. Their main task is to kill and paralyze the victim, as well as protect and scare away the aggressor.

The mechanism of action of Latrotoxin, a component of most neurotoxic poisons

By its nature, it is a presynaptic neurotoxin, since the point of action of Latrotoxin is the presynaptic nerve ending. There, the dimeric toxin is able to contact protein receptors with a molecular weight of ~95,000, as a result of which the resulting complex induces the permeability of biomembranes and becomes a channel for calcium cations - triggering the release of neurotransmitters and accelerating this process by 1000-1500 times. When reserves are depleted, after 30-50 minutes a complete block of neuromuscular transmission occurs. This ultimately leads to overstimulation of the muscle motor neuron ganglia.

Consequences of a spider bite

There are no consequences after being bitten by non-venomous spiders. The maximum that can be is a small pinpoint scar, of which in a short time there will be no trace left. The situation is completely different with the bites of poisonous spiders. The most serious local complications in this case may be necrosis of the skin in the bite area. The extent of such necrotic changes can reach 10 centimeters and depends on the concomitant infection.

General consequences develop only when bitten by poisonous spiders. They may appear:

Persistent and prolonged swelling of the affected segment;
Bleeding from the stomach and intestines or the formation of blood clots in blood vessels;
Convulsive readiness of the brain for a certain time after the bite;
Headaches;
General weakness and muscle-bone pain;
Kidney and liver failure, if these organs were sick before the bite;
Fatal outcome for weakened people with severe concomitant pathology or lack of treatment for bites of poisonous spiders.

Causes

The main pathogen is toxins secreted by the mouthparts (chelicerae) of spiders:

neurotoxic poisons (Δ-atracotoxin of the most dangerous Australian spider Atrax robustus, α-latrotoxin of the black widow and karakurt) have a direct effect on the structures of the central nervous system of the attacked individual by such representatives of spiders as karakurt and black widows;
necrotic poisons (containing the dermonecrotic substance sphingomyelinase) are produced by spiders of the sicariid family.

It is important to remember that spiders themselves do not attack people or large animals. In dangerous situations, they prefer to flee. Worse, if a person is caught in a web or a tenet cocoon designed to catch insects, then the spider may instinctively attack the victim. However, most often spiders bite people when they accidentally crush or step on them. It is important to know that the most dangerous representatives of spiders are the Australian species Atrax robustus, since they tend to climb into human dwellings - cool and damp, where they establish their homes and trapping nets for fairly large insects and animals.

Male and female Atrax robustus

First aid

Despite the fact that local and systemic symptoms caused by a bite usually go away spontaneously after a few hours, it is still better to know and carry out a number of preventive measures to prevent the likelihood of complications. Remember that ambulance is especially necessary for elderly people, hypertensive patients, children and pregnant women.

What to do if bitten by a spider?

It is important for anyone to know what to do if they are bitten by a spider, because a few simple steps can help save a life:

To be able to identify the spider, try to catch it or save its body if it was crushed;
wash the bite site with soap and water and wipe with alcohol; in general, sterilization can be carried out by the same treatment as for an infected wound;
immobilize the affected limb;
do not apply pressure bandages, but apply something cold, such as ice;
take an antihistamine to prevent an allergic reaction;
According to some reports, if a karakurt is bitten, immediate cauterization of the bite site with a match head can help.

First aid for a bite

What to do if you are bitten by a spider depends on the type of offender. If it is impossible to determine whether it is poisonous or not, then you should act from the position of greatest danger and treat the damage as a potential threat. In this case, it is better to play it safe than to let the situation take its course and wait for the victim’s condition to worsen.

To slow down the effect of the poison, it is necessary to accurately localize the site of the skin lesion and the proximity of the vessels where the poison could penetrate. If possible, the victim is fixed in an advantageous position, for example, with a lowered limb if the bite was in the arm or leg. This slows down the spread of toxins.

Since it is the effect of the poison that is destructive for the victim, first of all all attention is focused on the site of the bite. It is washed and disinfected. The victim, if he is conscious, should be given water to drink so that the poison leaves the body faster. As soon as first aid has been provided, you must contact the clinic.

Medication assistance

Medication assistance does not differ in the variety of drugs. For severe pain, a painkiller, such as Paracetamol, is given. If the first signs of an allergy to a spider bite develop, immediately take any antihistamine you have on hand. These may be drugs Cetirizine, Loratadine, Erius, Suprastin, Diazolin, Cetrin and other drugs.

Important! Some medications can enhance the effects of toxins, which in most cases others are not aware of. If the patient’s condition worsens, he is immediately consulted at the clinic, and if necessary, an ambulance is called.

Help at home

If a person knows for sure that this spider is not poisonous, then the following must be done:

Visually inspect the damaged area and, if there is contamination, remove it.
Disinfect the skin with hydrogen peroxide, iodine or brilliant green - whatever is in your home medicine cabinet.
Apply ice or another cold compress to prevent swelling.
Allergy sufferers are advised to take an antihistamine without waiting for symptoms.
After the measures taken, it is necessary to monitor the further development of the situation - the appearance of atypical signs, pain, numbness.
If the victim's condition worsens, consult a doctor immediately.

What to do if a spider bites a child

Due to the faster metabolism in children, you need to understand that the poison will act faster than in an adult. A significant disadvantage is weakened immunity, which often happens in sick children. In any case, doctors insist on hospitalizing the child immediately when the first complaints appear. First aid for severe pain is provided with Paracetamol, and for an increase in allergies - with any antihistamine medication.