Why do we cook and why it becomes easier when you hurt? Itching the skin of the body: why we scratch and why the scratching gives pleasure. Causes, Types, Science: Health Science: Knowledge, Innovation, Myths

10.05.2020

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Skin itch makes us instinctively scratisheled. Why does the scratch of one's own skin with the nails almost instantly makes it an unpleasant feeling? - wondered the browser.

Zoologist Jahe Travener began to experience the permanent skin itching around the age of 40 and continued to suffer from him until the death of 40 years later.

Why bright light makes us sneeze

Trever appealed for help to doctors common practice, dermatologists, neurologists and other medical professionals.

Trying to lime ticks, a woman threw dangerous pesticides in industrial quantities.

She applied wounds to themselves, trying to endure the source of irritation with nails from under the skin, and the fabric samples obtained in the process sent to the entomologists.

One doctor guessed it to send her to examination to a neurologist, but the patient managed to convince the specialist that his services were not required.

Happiness is an opportunity to hide every time Ogden Nash, the American poet

"Until now, no treatment method helped me completely get rid of ticks," she wrote.

Woman suffered mental disorder, known as Dermatozoic nonsense, in which patients are trying to find the physical reasons for the unpleasant sensations experienced by them, often applying wounds.

On the other hand, more common itch is everyday phenomenon, familiar to almost everyone.

And no one knows exactly what it is.

Right holder illustration IStock Image Caption Almost all people at least once a day have a feeling of itching, and not always the cause of his occurrence is known

The definition that most doctors and researchers still use has been proposed about 350 years ago by German Dr. Samuel Hafenreffer.

He wrote, in a somewhat streamlined form, that itching is any "unpleasant feeling that causes a conscious or reflex desire to scratch the itchy place."

In accordance with this explanation, whenever you scratch, the phenomenon causing this action is itching.

Perhaps this is a definition and accurately, but the causes of itching it does not clarify.

At first glance, itching and pain - one field of berries. In our skin is a lot pain receptors, NOCITERS, transmitting in the spinal and brain information about the presence of various types of irritation.

Weak stimulation of nocceptor causes the feeling of itching, strong - pain.

So read the theory of intensity, according to which noociceptors have no specialization.

But there is an alternative theory of specificity, involving the various properties of various nociceptors: some are responsible for the feeling of pain, others - for the feeling of itching.

However, perhaps the same receptors are responsible for both sensations, somehow determining different kinds Impact on skin.

Obsessive scratching

The fact that the feeling skin itch It may be caused by different reasons, does not fully explain this phenomenon.

Itching is strong - this feeling is familiar to the majority of us, and may arise, for example, after the bite of an insect.

There is also chronic, pathological type of itch, caused by dry skin, eczema, psoriasis and other skin diseases.

Brain tumors, multiple sclerosis, chronic liver failure, lymphoma, aids, hypofunction thyroid gland And the damage to neurons can also cause chronic itching.

Right holder illustration IStock Image Caption Pain from skin combing is very different from pain when burn

It is more curious that the feeling of the ferrous can be reduced by painful incentives.

Haning is weak, but still pain incentive, however, a slight feeling of pain that we experience, scratching nails on the skin, really helps from itching - as well as applying to the place of irritation of cold or hot objects, capsaicin (alkaloid giving pepper burning) or even The impact of weak electrical discharges.

At the same time, paradoxically, possible by-effect Reception of analgesics designed to remove pain - improving sensitivity to the feeling of itching.

Despite the apparent similarity between the mechanism of feeling of pain and the feeling of itching, there is one very obvious difference between them.

When we experience pain, then reflectively remove from the source of this feeling. Try to bring your hand as close as possible to the open fire, and you will immediately want to remove it.

But the reflex of scratching (or "reflex processing"), on the contrary, attracts our attention to an irritable skin area.

This phenomenon can be explained from the point of view of evolution: the close look at the place of irritation and quick scratching it - more effective method eliminating the insect creeping on the skin, rather than reflex removal.

This is how it works on the example of a mosquito bite: skin cells highlight chemical substance (As a rule, histamine), encouraging nociceptors to send an appropriate signal in the spinal cord, from where it on the beam of the nerves, known as the spinal thalia, reaches the brain.

In 2009, the researchers conducted an experiment - injected inseco-like primates of histamine in order to cause the sensation of itching in their feet, measuring with the help of an electrode activity of the spinal thalamic path of animals.

Immediately after injection, the activity of neurons has risen sharply. When the researchers scratched the place of irritation, neuron activity decreased.

So it was found that scratching affects the activity of the spinal thalamic path, and not the brain. (Indeed, there is no "center of the ferry" in the brain).

But in cases where the scratching preceded injections, it did not bring anything to the experimental.

That is, somehow the spinal cord "knows" when the scratching should help, and when not.

Right holder illustration IStock Image Caption Perhaps scratching helped our ancestors to get rid of annoying insects

Are you already squeezing? If so, it is because, like the yawn, itching can be "contagious."

Doctors say that after taking patients with scabies, they themselves begin to be reflexively.

Somehow the researchers held such an experiment - they read the lecture on the subject of itch specifically in order to find out whether the audience would show the corresponding symptoms.

And it worked: the shooting of hidden cameras showed that those present scratched during the lecture much more often than during the report on a more neutral theme.

The "contagious" itch is also observed by the monkeys - perhaps it is explained by the fact that it is possible when they do others, it can be beneficial from the point of view of the survival of the species.

In the article published by Journal of Investigative Dermatology in 1948, Neurophysiologist George Bishop from Washington University's Medical School in St. Louisa so described this paradox: "The fierce combing of the item plot, which would cause pain in any other place, can deliver great pleasure ".

However, although the scratches left on the back of a beloved person in a rustling of passion may be very pleasant, combing capable of leading serious problems in patients with chronic diseasesaccompanied by itching.

So, the patients with eczema say that it is not scratching until it turns out, but until the combing process will no longer cause pleasant sensations.

"Happiness is an opportunity to hide every time he wants," the American poet Odden Nash said. Perhaps he himself did not guessed how the right was.

Read on english language You can on the site.

The need to scratch the back can bring to the handle. If you have sharply worried about the back, use one of the many ways in order to urge irritation. To begin with, try scratching your own nails. If you do not get to the back, try to help yourself with reservoirs. If you are often encountered with this problem, you must take action and solve the problem of itching skin.

Steps

Use nails

Try to get to the itchy place yourself. The easiest way to scratch your back - do it with your own hands. To do this, make one or both hands behind your back and try to find the place that itchs. If your shoulders are squeaked, lower or top part The backs, most likely, you can scratch and ourselves.

Do not fumble too much. Do it gently and gently. To be too strong combing can damage the skin, thereby enhancing itching. In the future, this may worsen itching.

Twist your attempts to learn itching. Despite the fact that Chesia can give pleasure, you should not resort to it too often. Itching will not pass if you scratch it too long. If itching became the result of infection or rash, it will only aggravate the situation.

Ask help from a friend. If the spinning area is located in the center of the back, it will be very difficult to get to it. Ask a friend, family member or soul mate to help you. Ask this person to scratch your back and show where you have itching. Ask it not to scold too much, otherwise itching only worsen.

Using undergraduates

Buy chemicals for the back. Chesits for the back are sold in many beauty salons, supermarkets and cosmetic salons. This device is designed to scratch hard-to-reach places on the back. As a rule, they are long wooden sticks with slightly pointed edges, which are designed to alleviate itching.

Depending on the type of chemicals, some of them should not be used on bare skin. The use of chellices with very sharp edges can negatively affect your skin.
As with the usual itch, do not comb your chearl too often. This can lead to the exacerbation of itching. If the cause of it became a rash, excessive cheese will make it all worse.

Wrap a rough tissue around the blade. If you can not get to the back, make a chearlic of coarse fabric and blades. To do this, take the shovel and wrap it with a rough cloth. If necessary, fix the rag with a gum. Use this device to scratch your back.

Use water pressure in the shower. If you have a removable shower nozzle, use it to scratch your back. Turn the water rigorously and direct the shower head on this item. Perhaps it will weaken itching.

Scratch your back about a rough surface. If the pocket garbe does not help, let's spend the back of the rough surface. For example, swell your back about a rough wall, wood, carpet, wall angle and other similar surfaces. It should facilitate itching a little.
- Use this method with caution. If you decide to scratch outside the house, be sure to do it in clothes to accidentally do not put bacterib or toxins. For example, the same brick wall may be incredibly dirty.
Use a comb. The back can also scratch the usual comb. The hair brush is better to cope with this task, as its design is similar to the garlic for the back. Take the brush by the handle, get her back and spend on the item.
- Rinse the comb if you have a sweaty back, and you used it right on the skin.
- If you have taken someone else's comb, do not forget to first ask permission.

Elimination of itching

Attach a cold wet compress. Low temperatures have a much more favorable effect than combing. Attach the ice package with ice, which you can buy in any nearest pharmacy. In no case do not apply the ice package directly to the skin. Before applied ice, clog it into a rag or paper towel.

Have you ever scored a back in a hard-to-reach place? That was a flour! But as soon as you managed to scratch, immediately became easier. And a moment later, this place was again started, as if no one was smaller.

In general, you can have something to be bored even while reading this book. This property is relatives itching with zoo - you hear how someone yawns, and it can already cause it. Well, the brain is involved in the appearance of itching, and the brain, as if a hypnotized audience during a magical show easily suggests suggestion.

Pain and itching are two sensations perceived by our nerves, but they are very different. Many researchers studied pain throughout for long years: What causes it, the symptom of which it can be and how it can be reduced.

As for the itch, no one ever practiced seriously. Scientists know amazingly little about him and as amazingly little can be taken in many cases when you have something itching. There is no wide field for university and laboratory studiesSo far from every day we learn about itch something new.

If you believe "New English Medical Journal", all knowledge gained about pain can be applied to itch. Both of these sensations are transmitted in the form of electrical pulses through nervous cells (neurons).

From the neuron, like a tentacle from the starfish, mooring the fibers. There are three main types nerve fibers - A, B and C. Feeling of pain and the feeling of itching are transmitted by C-fibers, which are the most small of the three (C-fiber also conduct electrical impulses slower than other fibers).

However, some scientists believe that the "neurons of itch" may differ from the "neurons of pain" and each of them uses C-fiber to convey their excitation impulses.

There are many confirmation of the fact that pain and itching go different ways. For example, when you have something hurts, the central nervous system produces natural opiates that act as codeine or other painkillers. But the same opiates, according to scientists, in reality can increase itching. In fact, the drug blocking opiates can also facilitate some uncontrolled itching.

Like pain, itching can be due to a huge number of reasons - from ordinary to the most serious: insect bites, poisonous ivy, burns from the sun, dry skin, urchitis, lice, ticks, chickenpox, Cort, reaction to medical preparations, allergies, skin infections, fungal diseases, anemia, psoriasis, diabetes, hepatitis, cancer ... All of the above can trigger the reaction of the nervous system.

How does this happen? Take for an example of an insect bite. When you bite, suppose, a mosquito, as a response to the remaining mosquito, your body produces histamine. Histamine causes a feeling of itching, spreading around the nerves. (Histamine is what makes our eyes hide during flowering season; antihistamines block histamines and contribute to improved well-being.)

Why does Chesia help, but only temporarily? Although scientists do not know all the details, however, they say that the scan of stimulates certain nerves that help to regulate the movement of the pulses of itching through cells. Thus, the cheaning temporarily suspends the movement of the pulse of itch.

But no matter how nice it was to be, Chesia may eventually only strengthen itching. You just get into vicious circle: The more scratch - the more itches. Your cheania stimulates the nerves that cause itching, and thus enhances it. And now you can no longer stop, but so you can damage the skin and make an infection.

So, how best to get rid of itching? Try wet cool clothes, bathtub with food soda or oatmeal, lotion or gels with aloe extract. Try to treat a small itching to restrict ourselves to your home equipment, especially since scientists themselves recognize how little they know about the nature of the itch.

Itch and many accompanying trouble can be caused by a huge amount reasons. To accurately install the source, of course, to visit the doctor, but here it is the problem here - to which specialist is recorded?! Or go to everything in a row - the inspection is never superfluous! Let's deal with what reasons are and what kind of doctor is worth visiting.

With a strong, non-passing scalp before Contact your doctor! Do not pull! The earlier you refer to, the less the consequences will be!

Probable reasons

Seborrhea, Dragnet

Wrong work song hardware leads to the emergence of large hair problems. One of the very unpleasant is dandruff (Seborrhea), accompanied by unbearable itching and damage skin cover. And also covered with white scales shoulders and backs. Just these scales and are the source of itch, it is they who annoy the skin.

In light cases, dandruff is perfectly treated independently at home. More complex cases are best treated together with a trichologist, and approach this complex and tune in to the duration of the process.

Dry leather scalp

Again, the wrong work of the sebaceous glands and some more and skin cover of the head. The glands are actively trying to remove dryness and protect the weakened skin from the negative effects of the medium and thus the entire surface is covered with a layer of sebum. Hair starts to quickly get dirty, sticks a lot of dirt, the bacteria and microbes are developing. You can mistakenly suspect bold skin and greasy hair type. The rapid washing of the champions even more dries the skin, cracks and scratches strongly. After washing, everything flocks and electrified, the hairs are shaking and rolled.

This problem does not work well, replenishment in the body of vitamins and trace elements, the right and healthy nutrition, Compliance with the rules of washing, drying, locking curls from the sun, wind, frost.

Fungal defeat

it serious diseasesrequiring compulsory treatment. In addition to the permanent chapel on the skin, there are also plaques (deprived), which look very repulsive. It is best to undergo a course of treatment in medical institution Under the supervision of a dermatologist specialist, but if it is for some reason it is not possible, then try to remove the symptoms by wraps from tea tree oil and special antifungal shampoos.

Another very serious defeat, which also requires mandatory and urgent treatment (it is necessary to visit the dermatologist). Most often it is lice. You can jump over the company anywhere, especially where there are large crowds of people or big staff teams. You can detect under a magnifying glass, carefully examined the scalp (better if the doctor does). Tick-borne infection will not be able to detect at home.

Treatment from pediculosis is sufficiently simple and not long in time. Special shampoos and some folk remedies will do their job.

Allergy

Perhaps one of the most common sources of skin serb, and all because lately the incredible number of new allergic reactions. The main reactions to food. Also, many today have encountered allergies to hair care products (shampoos, balms, masks, styling ...) and decorative cosmetics. It is usually accompanied by rash, redness, itching, sometimes by swelling.

Allergy happens when changing the usual hair care. If the return to the old medium of the problem of allergies does not solve, then you should contact a trichologist.

The solution to the problem is to search for allergen and naturally in its elimination. It is best to do this in the Allergist's office.

Allergy to paint

It also happens quite often, especially if the master used not very high-quality paint or paint containing ammonia or hydrogen peroxide. The exit here is one: Be sure to control what exactly the master paints you and choose for staining non-ammmoniac paints or shedding shampoos. In addition, it is desirable to carry out a test for allergic reactions before procedures.

Allergies to powders

Washing powders, air conditioners for linen contain many different chemical components. Some of them can cause skin irritation, and, accordingly, allergies and itching.

Stresses, neurosis

The source of many of the most diverse problems with the body is nervous overvoltage, stress, depression, neurosis. The hair and scalp is also not bypassed. Stress can cause both hair type shift, and violations in the work of the sebaceous glands, and spasms blood vessels, and problems with microcirculation of blood. Against this background, the metabolism suffers greatly and irritation of the skin arises.

To remove this irritation first need to exclude stressful situations and calm their nerves, drink a course of soothing drugs (discharged by a neuropathologist when handling), carry out massage of the scalp and cervical department spine.

Incorrect nutrition

Excessive use of sweet, sharp, coffee, smoked, canned and other. It is not so healthy foods And their overeating inevitably affects the skin: dermatitis, eczema, acne, rash. These skin manifestations are always accompanied by itching and strong combing rash seats. Certray to this problem is simple enough: to eliminate the "harmful" food, drink more simple water, consume lean products with a small amount of spices. Itching and rash will quickly leave!

Wrong headdress

A close and synthetic headdress often causes an unpleasant feeling on the head. The debate further exacerbates the situation. I want to scratch all right and as quickly as possible. The exit here is one - immediately change the headdress to a more pleasant, out of the natural material, and besides that, different hats should be worn at a certain temperature () and try not to overheat the skin of the head, as well as not to translate.

In addition to these major reasons, there are also secondary. These include:

blood circulation disorders;
gTS diseases;
passive lifestyle;
frequent use of phenomena, bad ...;
overvoltage ...

The reasons are of course many and paint each can be very long. If there is no most of your cause, it means to look for a specialist in more rare. But the reason why the skin of the head is it necessary to find, as it may be a symptom of a serious illness, and it becomes problematic in a hairdresser.

Skin itch makes us instinctively scratisheled. Why does the scratch of one's own skin with the nails almost instantly makes it an unpleasant feeling?

Text: Jason Goldman / BBC Future

After spending 17 years in an attempt to get rid of the disease, a woman published a scientific work describing the history of her illness in medical journal Proceedings of the Entomological Society of Washington - Perhaps in an attempt to find someone who could facilitate her suffering.

The trave applied for help from general practitioners, dermatologists, neurologists and other medical professionals. Trying, the woman poured pesticides in industrial quantities. She applied wounds to themselves, trying to endure the source of irritation with nails from under the skin, and the fabric samples obtained in the process sent to the entomologists.

One doctor guessed it to send her to examination to a neurologist, but the patient managed to convince the specialist that his services were not required. "Until now, no treatment method helped me completely get rid of ticks," she wrote.

"Happiness is an opportunity to hide every time when he wants"

The story of the trave is similar to the stories of other people suffering from dermatozoic nonsense, but such cases are very rare: they take less than 2.5% of working time in dermatologists.

On the other hand, more common itch is everyday phenomenon, familiar to almost everyone. And no one knows exactly what it is.

Definition that most doctors and researchers still use, offered about 350 years ago German doctor Samuel Hafenreffer. He wrote, in a somewhat streamlined form, that itching is any "unpleasant feeling that causes a conscious or reflex desire to scratch the itchy place."

In accordance with this explanation, whenever you scratch, the phenomenon causing this action is itching. Perhaps this is a definition and accurately, but the causes of itching it does not clarify.

At first glance, itching and pain - one field of berries. In our skin there is a lot of pain receptors, nociceptors transmitting information about the presence of various types of irritation in the spinal and brain. Weak stimulation of nocceptor causes a feeling of itching. So read the theory of intensity, according to which noociceptors have no specialization.

But there is an alternative theory of specificity, involving the various properties of various nociceptors: some are responsible for the feeling of pain, others - for the feeling of itching. However, perhaps the same receptors are responsible for both sensations, somehow identifying various types of exposure to skin.

Obsessive scratching

The fact that the sensation of the skin can be caused by different reasons is not fully explained by this phenomenon. Itching is strong - this feeling is familiar to the majority of us, and may occur, for example, after the bite of an insect.

There is also chronic, pathological type of itch, caused by dry skin, eczema, and diseases. Brain tumors, multiple sclerosis, chronic liver failure, lymphoma, AIDS, thyroid hypofunction and neuron lesions can also cause chronic itching.

In addition, the feeling of itching is associated with psychological and cognitive factors, not all of which are so terrible as dermatozoic nonsense.

Obsessive scratching can be a manifestation of obsessive-compulsive disorder; At the same time, the permanent combing of the skin can lead to it mechanical damagethat only aggravates the problem.

It is more curious that the feeling of the ferrous can be reduced by painful incentives. Haning is weak, but still pain incentive, however, a slight feeling of pain that we experience, scratching nails on the skin, really helps from itching - as well as applying to the place of irritation of cold or hot objects, capsaicin (alkaloid giving pepper burning) or even The impact of weak electrical discharges.

Despite the apparent similarity between the mechanism of feeling of pain and the feeling of itching, there is one very obvious difference between them. When we experience pain, then reflectively remove from the source of this feeling. Try to bring your hand as close as possible to the open fire, and you will immediately want to remove it.

But the reflex of scratching (or "reflex processing"), on the contrary, attracts our attention to an annoyed area of \u200b\u200bthe skin. This phenomenon can be explained from the point of view of evolution: the close look at the place of irritation and quick scratching is a more efficient method of eliminating the insect skin, rather than the removal reflex.

This is how it works on the example of the skin cells highlight a chemical (usually histamine), encouraging nociceptors to send an appropriate signal in the spinal cord, from where it on the beam of the nerves, known as the spinal thalias, reaches the brain.

In 2009, the researchers conducted an experiment - injected insecto-like primates of histamine to cause a feeling of itching in their feet, measuring with the help of an electrode activity of the spinal thalamic path of animals. Immediately after injection, the activity of neurons has risen sharply. When the researchers scratched the place of irritation, neuron activity decreased.

So it was found that scratching affects the activity of the spinal thalamic path, and not the brain. (Indeed, there is no "center of the ferry" in the brain). But in cases where the scratching preceded injections, it did not bring anything to the experimental. That is, somehow the spinal cord "knows" when the scratching should help, and when - no.

Are you already squeezing? If so, then this is because, like the yawn, itching can be "contagious." Doctors say that after taking patients with scabies, they themselves begin to be reflexively.

Somehow the researchers held such an experiment - they read the lecture on the subject of itch specifically in order to find out whether the audience would show the corresponding symptoms. And it worked: the shooting of hidden cameras showed that those present scratched during the lecture much more often than during the report on a more neutral theme.

The "contagious" itch is also observed by monkeys - it is possible that it is explained by the fact that it is to be made when others do it, it can be beneficial from the point of view of the survival of the species.

And think about what: scratching is usually not considered a painful process - on the contrary, it can deliver pleasure.

In an article published by Journal of Investigative Dermatology in 1948, neurophysiologist George Bishop.from the medical school of the University of Washington in St. Louis, this paradox described this paradox: "The fierce combing of the items, which in any other place would cause pain, can deliver great pleasure."

However, although the scratches left on his back of a beloved person in a rustling of passion can be very pleasant, combing capable of leading serious problems in patients with chronic diseases accompanied by itching. So, the patients with eczema say that it is not scratching until it turns out, but until the combing process will no longer cause pleasant sensations.

"Happiness is the opportunity to intend every time when it wants," the American poet said somehow Ogden Nash. Perhaps he himself did not guessed how the right was.

(Thodonal / iStock)

Still, all other organs of our body are securely packed inside, where they are completely defended the immune system. The skin is the first level of protection against the environment, it is in constant contact with the world around the world, so it is logical that she developed its own ways to protect.

But all this does not explain why itching is manifested in such a unique, terribly annoying feeling.

Ten years ago, scientists believed that itching is simply another, weaker type of pain, the same epidermis receptors, which in the form of chemical and electrical signals transmit reports about the bone marrow pain in the head.

But now we know that itching has its own network in which its own chemical compounds and cells participate.

And although we all react to pain in different ways, itching all the same desire.

Scratch.

It turns out, Chesia causes weak pain signalwhich flies to the brain and interrupts the zead signal. This gives us a feeling of satisfaction. That is why itching can be removed, pinchering or slapping the broken skin area.

Unfortunately, some of the chemical compounds that give relief, in particular, serotonin - can simplify the path to re-appear the signal of the itch.

That is why Chesing sometimes causes even more itching, which immediately want to scratch ... a person goes into the cycle.

The cycle leads to damage to nerve endings and, as a result, an uncontrolled itch, which has no stimulus technically. When this happens, disorder is developing.

There are many different reasons for its appearance. Sometimes researchers do not even know primary cause. Sometimes a culprit becomes a viral infection attacked nervous system. So the post-ahead it's sometimes the complication of a sliding linguing.

The shoulder itching is caused by a squeezed nerve in the neck. There is also aquatic itching, which appears when the skin with water is in contact. Some cases of such disorders were associated with a very rare state, when a person has too many red blood tauros.

All these disorders make people feel the incessant itch, which does not respond to Chesia.

How to stop itching?

In the whole history, humanity came up with a lot different ways. Ancient Greeks and Romans used mineral baths and animal fat. Persians enjoyed silver. In ancient China, Menthol was treated. And from the XIII century, a camphor was used, a chemical obtained from a camphor tree, which was historically used to create explosives.

Today are used anestheticsCorrection of complete skin numbers anti-radical meansin which, for example, a chili extract is used, antihistaminefunds I. steroid cream.

In any case, remember that the point is not only in the skin and the causes of the appearance of itching can be the most different. Do not self-medication, always contact your doctor.

| Read also people believe in these myths about HIV infection?

| Read also the advantages of embrace from the point of view of science

Skin itch makes us instinctively scratisheled. Why does the scratch of one's own skin with the nails almost instantly makes it an unpleasant feeling?

Text: Jason Goldman / BBC Future

After spending 17 years in trying to get rid of the disease, a woman published a scientific work describing the history of her illness, in the medical journal Proceedings of the Entomological Society of Washington - perhaps in an attempt to find someone who could facilitate her suffering.

"Happiness is an opportunity to hide every time when he wants"

The story of the trave is similar to the stories of other people suffering from dermatozoic nonsense, but such cases are very rare: they take less than 2.5% of working time in dermatologists.

On the other hand, more common itch is everyday phenomenon, familiar to almost everyone. And no one knows exactly what it is.

In accordance with this explanation, whenever you scratch, the phenomenon causing this action is itching. Perhaps this is a definition and accurately, but the causes of itching it does not clarify.

Obsessive scratching

In addition, the feeling of itching is associated with psychological and cognitive factors, not all of which are so terrible as dermatozoic nonsense.

Obsessive scratching can be a manifestation of obsessive-compulsive disorder; At the same time, the constant combing of the skin can lead to its mechanical damage, which only aggravates the problem.

Are you already squeezing? If so, then this is because, like the yawn, itching can be "contagious." Doctors say that after taking patients with scabies, they themselves begin to be reflexively.

And think about what: scratching is usually not considered a painful process - on the contrary, it can deliver pleasure.

"Happiness is the opportunity to intend every time when it wants," the American poet said somehow Ogden Nash. Perhaps he himself did not guessed how the right was.

Do you know that the scratching of one part of the body washes to be more pleasant than the other? Jil Josipovich, Doctor of Medical Sciences, Professor of Dermatology, Founder of the International Forum on Studying Itch, says that psychological factors are likely to help determine how nice to scratch one or another part of the body.

Funny study

"Most studies of itching were sent only to a simple study of the skin of the forearm, ignoring the well-known fact that the back is a preferred scratch destination, as evidenced by the popularity of scrapers for the back," says Dr. Yosipovich.

The back, forearm, the ankles are the most common seats for scanning with neurodimer - skin condition associated with chronic itching and scraps, which, in turn, leads to thickening of the skin. It sometimes occurs in people with eczema, psoriasis or nerve disorders, such as anxiety or depression.

Dr. Yosipovich and his co-authors seized 18 healthy adult volunteers who did not have diseases provoking itching. The researchers cause them itching on his back, forearms and ankles, carefully rubbing small, pointed pieces of tropical bob, which is known, causes a strong itching on the skin. Then they asked volunteers to estimate the intensity of the separation on a scale from 1 to 10 with a 30-second interval.

At the next stage of the study, the researchers used a tiny brush so that volunteers could get rid of itching immediately after its occurrence. Volunteers asked to estimate the intensity of the ferrous and pleasant sensations from scrazing on a scale from 1 to 10, again with a 30-second interval.

Scientists have discovered that, on average, the intensity of itching and the pleasant of Chesia were significantly more on the ankle and back than on the forearm. On the back and forearm, the friend of Chesia decreased with time. But on the ankle of the feeling when scratching continued to be as pleasant, even how the intensity of the itch decreased.

Dr. Yosipovich and his colleagues say they are not sure about the causes of this phenomenon. Previous studies have shown that the density of the nerve endings below on the legs, so this cannot explain why the pleasure of Chesania, even small, was the greatest on the ankle. And, notes the doctor, there are a lot of nerves on the face, but people do not often complain about itching on the forehead or cheeks.

His goal, according to him, is to develop drugs that can cause pleasant relief, as when scratching, without damaging the skin.

Almost everyone nicely stroking the head, because it is so reminiscent of childhood and mother-maternal hands. Scientists have found out why this is what makes such pleasure. It turns out that some nerve endings on the human skin send signals of pleasure in the brain when they are activated at a certain speed.

When a person is stroked at a speed of 4 centimeters per second, special group Nerves - C-fiber, which usually transmits a signal about pain, fixes pleasure. This was found to scientists from Britain, Germany and the United States in their research, which was published in the journal. Nature Neuroscience..

The researchers demonstrated the reaction of C-fibers on volunteers using a "tactile stimulator" - a mechanical hand with a soft brush. While the robot stroked the volunteers, scientists recorded the C-fibers signals that arose from them. "If you got into the eyes of the Sorink, the tooth hurts or you bite the tongue, you feel pain, because there are a lot of C-fibers. In our study, we showed that C-fibers have other functions. They are not only receptors of pain, but also receptors of pleasure, "Professor Francis McGlone said one of the researchers (Francis McGlone). The results of the study, according to scientists, explain why touching when combing and hugs are so pleasant.

The nerves with the receptors of "pleasure" are on the skin, covered with hair, but they are not on hand palms. "We believe that this Mother Nature takes care that the contradictory messages did not go to the brain when a person uses this functional tool," said Professor Mac-Gloun.