Leech bite

Leeches are well-known annelids that can easily be found in almost any fresh water body, especially in places with stagnant water. Both children and adults also know that such worms bite quite unpleasantly, sucking out a relatively large amount of blood. What is a leech bite, how dangerous is it, and what to do in such a case?

Is a leech bite dangerous?

Any therapist can tell you about the benefits of leech bites. However, such benefits are really present if we are talking about medicinal worms that are specially bred for medical use.

If the worm lives in the wild, its bite can be dangerous in its own way: it is better to avoid it. [ 1 ]

In general, leeches are parasites that harm animals, fish, and can harm humans - for example, by infecting them with a disease transmitted through blood. In addition, after a bite, severe bleeding often develops, weakening the living organism. In nature, blood-sucking worms usually affect ungulates that approach water bodies to drink water. At the same time, the significant thickness of the skin that needs to be bitten does not frighten leeches at all. And they bite through human skin even easier.

What is the danger for people? Wild ringed representatives can cause the development of a disease called hirudinosis. This disorder appears due to the negative influence of bioactive salivary components against the background of the loss of a certain amount of blood of the victim. We can immediately reassure: such a disease is rare and does not develop from a single leech bite. Most often, people suffer who try to independently and illiterately engage in hirudotherapy, using not special, but ordinary worms.

Another possible cause of hirudinosis may be leech parasitism. However, parasitic leeches are not found in our country: such harmful worms can infect a person, for example, after a trip abroad. [ 2 ]

Epidemiology

Leeches belong to the subclass "annelids". Their basic habitat is fresh water bodies, mainly with stagnant water.

The world fauna has more than half a thousand varieties of leeches: among them, more than 60 species can be found in Russia, and 25 species - in Ukraine. The exact number of wild leeches living on the territory of our country is unknown, since we are talking about tens of tons, and this count has never been carried out.

The most dangerous species of leeches are found in southern countries – for example, in Ceylon, Malaysia, Sumatra, Borneo, New Guinea, Sri Lanka. [ 3 ]

Causes Leech bite

Leeches are classified by scientists as hematophages, meaning that they eat nothing but blood. In principle, the blood of any vertebrate animal is suitable, but preference is given to large mammals, including humans. [ 4 ]

The worm's digestive system is open with a mouth opening located in the anterior end segment. If you look inside the mouth, you can see small light formations that represent the jaw leech apparatus. There are three jaws here: two of them are lateral, and one is dorsal. The teeth are small and sharp, they can easily bite through even fairly thick skin.

After the pharynx comes the esophagus, and then the multi-chambered stomach intestine, where the blood consumed accumulates. Thanks to this accumulation, the worm is able to exist without food for several months. Interestingly, the blood in the leech stomach does not clot, is not affected by bacteria, and does not spoil.

Leeches' intestines empty several times a day.

The salivary apparatus deserves special attention; its outlets are located around the pharynx. The salivary secretion contains a large number of bioactive components that penetrate the tissues bitten by the worm. Saliva is secreted during the entire sucking act.

Leeches have significantly developed taste, tactile and olfactory abilities, which is very helpful in finding a food source. The first thing the worm reacts to is smell: this is why a leech will never bite a person who smells strongly of detergent, perfume or deodorant. If there is no irritating aroma, then the attack occurs almost immediately. The most favorite leech aroma is the smell of blood, to which there is a literally instant reaction.

Additional factors that contribute to the attack are vibrations of water caused by large animals or humans. The noise of the victim approaching is caught by the worms very quickly, after which they head straight to the sound source.

After sucking on the skin, the bite does not follow immediately: first, the leech needs to find the warmest zone with more intensive capillary blood circulation. Therefore, inflammatory elements on the skin often become the place of choice.

Therefore, if a person enters stagnant water without appropriate protection, does not have irritating odors (especially if there are scratches, inflammations and cuts with the scent of blood on the skin), then he may well become a potential victim of a leech attack. [ 5 ]

Risk factors

When leeches are near a mammal, and in particular, a human, they do not bite everyone. Like a radar, their olfactory system is “tuned” not only to search for, but also to sort out sources of blood food. They can sense the optimal aroma for themselves from several dozen meters away. At the same time, the aroma of detergents and cleaning products, toilet water, perfume, cologne, deodorant, and tobacco smoke is a repellent smell for them. [ 6 ]

In general, the following categories of the population are at risk of being bitten:

• travelers, tourists;
• inhabitants of damp and marshy areas;
• lovers of swimming in natural reservoirs, on spontaneous beaches;
• fishermen, hunters.

Pathogenesis

The end parts of the leech's body have peculiar suckers. The front one is formed from four to five segments, and the back one from seven segments, which makes it more powerful. After sucking, the worm bites through the skin: the bite can penetrate to a depth of one and a half to two millimeters, while salivary secretion gets into the tissue, which, among other things, includes the enzyme substance hirudin, which inhibits blood clotting processes. One leech usually sucks up to five milliliters of blood during one bite. After the "attack", a small injury remains on the skin, from which blood and lymphatic fluid can ooze for several hours. In general, after the "bloodsucker" falls off, an additional 5-30 ml of blood flows out of the wound. [ 7 ]

The salivary secretion of a leech usually contains the following enzymatic substances:

• hyaluronidase – a substance that improves tissue permeability;
• hirudin is a component that slows down blood clotting and blocks thrombin;
• histamine-like component – ensures the development of local inflammation to improve blood flow to the tissues in the bite area;
• substances that inhibit proteolytic enzymes – reduce the body’s overall inflammatory response;
• destabilase complex – has an antithrombotic effect by blocking platelet aggregation.

Other components of the secretion have a less pronounced effect, or their effect has not yet been fully studied. [ 8 ]

Symptoms Leech bite

The immediate moment of the leech bite is accompanied by a burning sensation, the intensity of which varies in similarity from a nettle burn to an ant or mosquito bite. Such sensations can be repeated periodically throughout the entire period until the worm falls off. The average duration of the sucking act is 20-40 minutes, and after falling off, blood continues to flow for some time. Post-leech bleeding can be stopped by applying a tight bandage to the wound. [ 9 ]

What does a leech bite look like? Usually it is a wound about one and a half millimeters deep, from which blood oozes. The victim may feel heat and general discomfort for several hours. A hematoma may form on the skin in the damaged area, indicating that blood has entered the tissue: at first the spot is bluish, then the color changes to yellow and disappears completely within a couple of weeks.

At the site of the bite, a specific triangular-shaped scar is formed, which gradually fades and disappears.

The bleeding after the worm falls off usually continues for several hours, and depends on individual coagulation parameters. People with excessive sensitivity may notice swelling, redness, and itching.

The itching is usually limited to the bite site, but can also be general. In both cases, it completely disappears within 3-4 days. The main condition for successful wound healing is to avoid scratching and damaging it, and to prevent infection.

The first signs of a leech attack are easy to notice, because it is hard not to notice the sharp burning sensation. Usually, a person grabs the affected area and discovers an "uninvited guest" there. We will talk below about what needs to be done at this moment and what is absolutely forbidden to do.

In some cases, for example, if a person is wearing shoes, a river leech bite is actually ignored. This often happens to fishermen, when the "bloodsucker" crawls into rubber boots and attaches itself to the skin on the leg. In such a situation, the trouble is discovered when changing shoes. The main thing is not to panic and not to tear the parasite away from the body. When tearing, its jaws may remain in the wound, after which the initially harmless bite of a wild leech will lead to irritation and infection of the tissues - the likelihood of complications will increase. [ 10 ]

Complications and consequences

Fortunately, most often, single bites cause only short-term discomfort. In the worst case scenario, you can “earn” an allergic reaction to a leech bite: they manifest themselves as intense itching, redness, swelling of the affected area of the skin. All these symptoms are a common manifestation of allergies. Although these symptoms are expressed in different ways: for example, some people just feel a little itchy from a leech bite, while others have a much stronger reaction, up to anaphylactic shock. [ 11 ]

In order to understand how serious the consequences may be, you should listen carefully to your body. Minor itching or just discomfort, without the addition of other painful symptoms, most likely will not be accompanied by complications. However, if the leech bite site is significantly swollen, there is an increase in temperature, general weakness and malaise appear, then it is recommended to visit a doctor for a consultation. Perhaps we are talking about a hypersensitivity reaction or an allergy.

Mild itching from a leech bite usually lasts for 3-4 days, after which it gradually subsides. If the itching does not go away, but rather increases, then a visit to the doctor is a must, and as soon as possible. [ 12 ]

The wounds themselves after a leech bite may take a little longer to heal than usual. However, during the entire healing period, they should not bleed, turn red, swell, become inflamed, and especially should not release ichor or pus. These signs often indicate the addition of an infection - that is, that inflammation is developing from a leech bite. This often happens if a person swims in a dirty pond or is in contaminated stagnant water. Treatment of inflammation should be carried out in a hospital, and in advanced cases, you even have to resort to the help of a surgeon.

To prevent complications, even a small redness after a leech bite should be treated with any disinfectant: alcohol, potassium permanganate solution, furacilin, fucorcin, chlorhexidine, etc.

Another type of complication is bleeding after a leech bite, which can be either small and short-term or significant and prolonged. Minor bleeding is considered one of the normal options. But heavy and prolonged blood loss, which is usually typical for people with poor blood clotting, can lead to various adverse effects. Therefore, if blood continues to ooze from the wound after a certain time after the bite, it is better to see a doctor and take measures to stop the bleeding. [ 13 ]

Bruises from a leech bite indicate that blood has seeped into the tissue: you need to monitor this area, and if the bruise increases in size, immediately consult a doctor.

How long does a leech bite last? Blood can ooze from the damaged area for 2-5 hours, but the wound itself takes much longer to heal – from several days to several weeks. The trace of a leech “attack” can remain on the skin for six months, depending on the individual characteristics of the human body. [ 14 ]

Diagnostics Leech bite

First, the doctor will send the victim to take tests:

• general blood test;
• coagulogram (checking the quality of blood clotting);
• determination of blood sugar levels.

If the clinical picture is unclear, auxiliary diagnostics are usually recommended:

• ultrasound examination;
• hormonal tests;
• involvement and consultation of specialized specialists.

It is important for the doctor to know the patient’s blood pressure readings and determine whether he or she has anemia. [ 15 ]

Differential diagnostics are most often carried out with mechanical injuries, vascular diseases, insect bites, rodents, and crustaceans.

Treatment Leech bite

Treatment for a wild leech bite usually involves stopping the bleeding and preventing an allergic reaction and infection.

Stopping bleeding is accomplished by applying a tight bandage - this is often sufficient. Hemostatic drugs are used only in severe cases.

To prevent the development of an allergic process, the patient is prescribed antihistamines Suprastin, Tavegil, Zyrtec, Fenistil.

In order to prevent secondary infection, the wound is treated with such preparations (optional) as brilliant green solution, iodine, fucorcin, weak potassium permanganate solution, furacilin solution, hydrogen peroxide. Alcohol solutions can also be used: propolis tincture, calendula, mullein, etc. are suitable. The question of the need to take antibiotics is decided by the doctor on an individual basis. [ 16 ]

First aid for a leech bite

The first thing to do when you find a leech on your body is to remove it. You should not try to tear the worm off, as its body parts may remain in the tissues and cause inflammation.

You cannot cut the parasite with a knife or other cutting objects.

You cannot sprinkle the wound surface with earth, cover it with swamp, and it is not even advisable to water it with water from a reservoir, as this can cause secondary infection.

And yet, what to do after a leech bite?

• You need to force the worm to let you go voluntarily by sprinkling it with salt, crushed tobacco, or pouring alcohol, vodka, any alcohol solution (even cologne), or table vinegar on it.
• To prevent infection from penetrating into the tissue, the wound must be treated using hydrogen peroxide, iodine, brilliant green, fucorcin, or an alcohol solution.
• To stop the bleeding, apply a tight bandage. If the bleeding is heavy, it is important to seek immediate medical attention.

If the parasite has entered the body – the esophagus, respiratory tract, genital tract – then you need to contact a specialist as soon as possible, since you definitely won’t be able to remove the worm yourself. Having drunk blood, it will increase in size and can block vital channels, so it needs to be removed as quickly as possible. [ 17 ]

Medicines that may be useful in case of a leech bite

Suprastin	Antiallergic drug based on chloropyramine. Tablets are taken with food, 3-4 per day (no more than 4 pieces per day). If a strong sedative effect, dizziness, or a drop in blood pressure occurs, stop taking Suprastin.
Zyrtec	An antihistamine drug based on cetirizine. Take 20 drops orally once a day. Zyrtec has minor side effects on the central nervous system, so treatment is usually not accompanied by drowsiness, increased fatigue, dizziness and headaches.
Fenistil	A systemic antiallergic drug based on dimethindene maleate, effectively eliminates itching and swelling after bites. The daily dose of the drug is 3-6 mg (in three doses). The standard dose is 30 drops three times a day. The beginning of treatment is often accompanied by drowsiness, which gradually passes.
Water pepper tincture	A herbal hemostatic agent, the effect of which is due to the presence of bioflavonoids in the preparation. The tincture reduces capillary permeability, normalizes the structure of the vessel walls, eliminates inflammation, accelerates blood clotting. Usually take 30-40 drops of the preparation up to 4 times a day, between meals. Possible side effects: headache, nausea.
Vikasol	The drug menadione sodium bisulfite is a hemostatic agent. Vikasol is administered intramuscularly, in a single dose of 10 mg, with a maximum daily dose of 30 mg. Possible side effects: jaundice, tachycardia, hypersensitivity reactions.

How to stop bleeding from a leech bite?

It often happens that after bites, swelling, red spots remain on the skin, and blood comes out of the wounds. A small amount of blood can be called a natural process, because during a bite, an enzyme function is activated that prevents blood clotting. You don’t want to lose your own blood, so you need to take measures to stop the bleeding. You need to prepare one of these remedies:

• brilliant green solution, fucorcin, iodine or alcohol solution;
• medical glue;
• oak bark infusion or diluted vinegar;
• Rescuer ointment, burdock oil, petroleum jelly or glycerin.

The wound is treated with one of the indicated means, after which a tight bandage is applied to the bitten area. Additionally, an ice pack can be applied on top. If the bleeding does not stop for more than 10-12 hours, despite the measures taken, then you should seek medical help. [ 18 ]

What to apply to leech bites?

What to apply to bite sites to speed up healing and get rid of unpleasant symptoms of itching and swelling? There are a number of effective remedies that are sold in any drugstore:

• Rescuer ointment is a universal balm with a resolving, antimicrobial, regenerating effect, accelerates healing, including inflamed bite sites;
• Boro Plus ointment is an antiseptic that quickly heals wounds in children and adults;
• Fenistil gel is an anti-allergic agent in the form of a gel (also available in drops and capsules), helps to avoid side effects after leech bites (in particular, eliminates itching);
• Bepanten is a universal product with active healing, moisturizing and regenerating effects;
• Epidel is an anti-inflammatory cream that stops the local development of inflammation, reducing itching and burning of the skin;
• Hydrocortisone ointment is a hormonal agent for external use that exhibits immunosuppressive, antiallergic, anti-inflammatory and antiexudative effects; not suitable for long-term use.

Folk remedies

There are many folk medicine recipes that can be successfully used for leech bites, and from different places. Therefore, you should focus on the types of plants that are present in your area. If the remedy helps, but weakly, then it is better to change it and replace it with another one.

• In case of severe bleeding of the wound, prepare a decoction of barberry bark or rhizome: pour boiling water (200 ml) over 30 g of raw material, leave for 15-17 minutes, filter and take orally 1 tbsp every hour until the bleeding stops completely.
• Apply compresses with a decoction of oak bark: pour 10 g of bark with one glass of boiling water, boil for 20 minutes and filter.
• Eat strawberries on an empty stomach (you need to eat at least 4-8 tablespoons of berries at a time).
• Apply chewed or crushed pure yarrow herb to the bitten area.
• During the day, drink tea made from nettle or yarrow leaves.

Herbal treatment

• To speed up healing, apply a washed nettle or burnet leaf to the wound.
• Prepare an infusion of yarrow: pour 250 ml of boiling water over 1 tbsp of crushed plant, leave for half an hour, filter and use for rinsing and lotions.
• Add parsley to all dishes and eat it until the condition is completely normalized.
• Prepare a powder based on willow bark. Take 1 g before bedtime with water.
• An infusion of strawberry leaves is prepared: 1 tbsp of leaves is poured with 200 ml of boiling water, infused until cool, filtered. It is used for washing and wiping wounds.
• Apply fresh cherry leaves to the bite sites.

Due to the presence of a large amount of tannins, calendula is successfully used to stop bleeding. The infusion of the plant is prepared as follows: 2 tbsp. of flowers are poured with a glass of boiling water, covered with a lid and infused until cool. Take 2 tbsp. of the product three times a day before meals. In addition, the infusion can be used to wash the areas damaged by bites.

You can also make a tincture from calendula: pour 1 tbsp of flowers with 100 ml of vodka, keep in a warm place for ten days, filter, squeeze. Take 30 drops of tincture three times a day before meals. To prepare a solution for rinsing, dilute 1 part of tincture in 10 parts of cool water.

Homeopathy

Various insect and parasite bites most often pass without consequences and specific therapy, but in some cases you have to seek qualified help. It is especially dangerous when a leech bite occurs in the neck and face area - primarily due to the high risk of soft tissue swelling and the development of allergies. If help is really needed, then proven homeopathic remedies will help to buy time. But it should be remembered that these drugs are not able to replace emergency medical care.

• Apis mellifica is a bee venom-based remedy that is particularly effective in treating swelling.
• Arnica montana is an effective drug, a drop of which is dripped into the wound, after which the unpleasant symptoms should disappear.
• Cantharis is a remedy for relieving the inflammatory reaction in the bite area.
• Carbolicum acidum is used in cases where certain general symptoms are present, such as general weakness, itching throughout the body, rash, and respiratory distress.
• Lachesis - helps with painful bites, with the affected area turning dark crimson.
• Ledum palustre - is considered one of the main homeopathic remedies for the treatment of any bites in general. It can be used as a first aid drug.
• Tarentula cubensis is a remedy for painful infected bites.

Prevention

Preventing leech bites is not as difficult as it seems at first glance. The main thing is to follow a few simple safety rules:

• You should not swim in bodies of water that are suitable for leeches to inhabit – first of all, this is stagnant water in ponds, lakes, and backwaters.
• When visiting countries where worms dangerous to humans live, it is advisable to avoid swimming in natural bodies of water, preferring pools or special fenced beaches.
• If you still need to dive into a natural standing body of water, you must wear a special protective suit.
• Bathing in any natural body of water should end with a careful examination of the skin.
• Since some species of leeches choose to live on the shores rather than in the water itself, you should approach water bodies with caution, taking protective measures: especially protect your legs, arms, and neck. If you are going on a long walk in nature in areas with a warm and humid climate, in areas with dense tropical vegetation, you should wear rubber boots or thick trousers tucked into your shoes and socks.
• The lower part of the trousers can be treated with dimethyl phthalate or indalone: this will repel worms. A similar effect is observed if the shoes are well lubricated with aromatic liquid soap, and the body is treated with toilet water or deodorant with a pronounced and persistent smell.
• If you are going to spend the night outdoors and there is a possibility that leeches will get into your tent, you should put several strips of cloth with salt in front of the entrance to repel them.

Forecast

Such a complication of leech bites as hirudinosis occurs mainly in topical countries. In the territory of the former Soviet Union, this disease is not widespread.

Prolonged presence of leeches on the body, as well as their presence in large numbers, can lead to significant blood loss, the development of anemia, severe headaches and general weakness.

Some dangerous leeches can carry diseases such as typhoid fever and paratyphoid fever, and the pathogens of these diseases can exist inside the parasite's body for 1-3 months.

In addition to the above problems, the bite wound is sometimes subject to secondary infection, which is especially dangerous due to the development of purulent processes.

It is worth noting that the complications mentioned are registered mainly in countries with hot and humid climates. In our country, a leech bite usually has a favorable prognosis.