- Pruritus is an unpleasant sensation that is usually secondary to a cytokine-releasing stimulus such as histamine.
- Histamine frequently produces a local inflammatory state at the site of a noxious stimulus, and its usual manifestation is pruritus.
- Scratching secondary to pruritus increases its intensity and a vicious circle is established.
- Pruritus frequently decreases with the use of anti-inflammatory analgesics, suggesting the transmission of the stimulus by means of painful or spinothalamic pathways.
Continuing with the relationship Pruritus and Pain;
- New experimental findings have found in relation to Pruritus, new neurological pathways and specific Central Nervous System (CNS) centers, in addition to another neurotransmitter involved in this unpleasant feeling, the Gastrin Releasing Peptide (PLG)
- Before I believed by certain experimental evidences in humans and social animals, that Empathy had to do with the scrape secondary to Prurito, as a type of behavior of socially accepted solidarity.
- Empathy understood as the emotional behaviors that human beings and animals close (phylogenetically with our species as primates and rats), recognize and share among their peers. The part of the CNS that regulates them, is the Limbic System (SL); Specifically: Frontal and orbitofrontal cortex, cingulate cortex, amygdala, hippocampus, thalamus, mammillary bodies and fornix.
- Regarding the relationship between Pruritus and Pain, it must be remembered that SL is related to all types of emotions, not only the Empathy and the Scraping Empathic Conduct in the presence of Scratch in some similar, even without sensation of Pruritus. SL is also related to the feeling of well-being, euphoria and happiness; To unpleasant emotions such as depression, anguish and fear.
- The latter, anguish and fear, often decrease the pain threshold; So that annoying or non-painful stimuli for certain people, such as local pressure or dermal scratching, can in very susceptible subjects be perceived as Pain and not as Itching.
http://www.redalyc.org/pdf/1339/133912609008.pdf
Continuando con la relación Prurito y Dolor;
- Nuevos descubrimientos experimentales han encontrado en relación al Prurito, nuevas vías neurológicas y centros del Sistema Nervioso Central (SNC) específicos, además de otro neurotransmisor involucrado en esta sensación desagradable, el Péptido Liberador de Gastrina (PLG)
- Antes de creía por ciertas evidencias experimentales en humanos y animales sociales, que la Empatía tenía que ver con el rascado secundario a Prurito, como un tipo de comportamiento de solidaridad socialmente aceptado.
- La Empatía entendida como las conductas emocionales que los seres humanos y animales cercanos (filogenéticamente con nuestra especie como primates y ratas), reconocen y comparten entre sus semejantes. La parte del SNC que las regula, es el Sistema Límbico (SL); específicamente: Corteza frontal y orbitofrontal, corteza cingulada, amígdala, hipocampo, tálamo, cuerpos mamilares y fórnix.
- Respecto de la relación entre Prurito y Dolor, hay que recordar que el SL está relacionado con todo tipo de emociones, no sólo la Empatía y la Conducta Empática de Rascado ante la evidencia de Rascado en algún semejante, aún sin sensación de Prurito. El SL está también relacionado con la sensación de bienestar, euforia y felicidad; hasta emociones desagradables como la depresión, angustia y el miedo.
- Estos últimos, la angustia y el miedo, con frecuencia disminuyen el umbral de dolor; por lo que estímulos molestos o no dolorosos para ciertas personas, como presión local o rayado dérmico, pueden en sujetos muy susceptibles percibirse como Dolor y no como Prurito.
http://www.redalyc.org/pdf/1339/133912609008.pdf
Pruritus (itch) and pain are closely related and both are sensed by C and Ad sensory fibres, but they must differ because they elicit different reflexes (scratch vs withdrawal). Itch is caused primarily by chemical stimuli such as histamine while pain is caused more by mechanical stimuli.
The following review article is excellent in explaining the molecular mechanisms of pruritus:
https://www.ncbi.nlm.nih.gov/pubmed/27939459
Dear Nemanja Zdravkovic
The reference article is very demonstrative of how the sensation of pruritus and pain are different, although both alter the quality of life. In the local inflammatory process, say for example on the skin; Where cytokines, bradykinin and histamine are released, directly stimulate nociceptive and pruriceptive neuronal receptors, sensations traveling through the spinal cord and integrating both at the thalamic and cortical levels, being consciously perceived as pain and pruritus.
In this case, antiepileptic and anti-neuritic drugs are capable of modulating and blocking the simultaneous transmission of pruritic sensation and pain, as is often the case in diabetic neuropathy.
Estimado Nemanja Zdravkovic
El artículo de referencia es muy demostrativo de como la sensación del prurito y el dolor son diferentes, aunque ambas alteran la calidad de vida. En el proceso inflamatorio local, pongamos por ejemplo en la piel; donde se liberan citocinas, bradicinina e histamina, se llegan a estimular directamente los receptores neuronales nociceptivos y "pruriceptivos", sensaciones que viajan por la médula espinal y se integran tanto a nivel talámico como cortical, percibiéndose en forma consciente como dolor y prurito.
En este caso, los medicamentos antiepilépticos y antineuríticos, son capaces de modular y de bloquear la transmisión simultánea de la sensación pruriginosa y el dolor, como sucede frecuentemente en la neuropatía diabética.
Dear Piers Nye
If histamine at the local level, as in the inflammatory processes of the skin, mainly causes pruritus sensation. On the other hand, when histamine and bradykinin are released around nerve paths and cranial arteries, they mainly cause local vasodilation pain at the site.
It is true that the immediate response to pruritus is scratching, and pain is the avoidance of nociceptive stimulation. Also, when itching, the simple action of scratching the skin decreases the annoying sensation by masking the sensation.
Estimado Piers Nye
Si la histamina a nivel local, como en los procesos inflamatorios de la piel, provoca principalmente sensación de prurito. Por otro lado, cuando la histamina y la bradicinina se liberan alrededor de trayectos nerviosos y arterias craneales, provocan principalmente dolor por vasodilatación local en dicho sitio.
Cierto que la respuesta inmediata al prurito es el rascado, y en el dolor es la evitación del estímulo nociceptivo. También, cuando hay prurito, la simple acción de rayar la piel, disminuye la sensación molesta por enmascaramiento de dicha sensación.
Dear Zahir Hussain
The article he provides is an excellent review of the anatomy and neurophysiology of pruritus.
In the last century it was considered that pruritus was a type of pain of low intensity, now by virtue of the latest discoveries on the matter, the nerve pathways leading to pruritus, pain, touch and both have been better known and delimited. Pruritus as pain.
In this article (which is only obtained in summary, if you want the extensive you have to buy it) specific nerve pathways for pruritus are already posed. In another article that I put at your disposal (and that is obtained in full text), this differentiation is explained in more detail:
- Primary sensory nerves are classified into 3 groups: nerves Aβ, Aδ and C, depending on their myelination, diameter and conduction velocity. The nerves Aδ and C are mainly involved in the conduction of the thermal sensation and pain / itching, whereas the nerves Aδ conducts the sensation tactile.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3694590/pdf/nihms480958.pdf
Estimado Zahir Hussain
El artículo que nos proporciona es una excelente revisión de la anatomía y neurofisiología del prurito.
En el siglo pasado se consideraba que el prurito era un tipo de dolor de baja intensidad, ahora en virtud de los últimos descubrimientos sobre la materia, se han conocido y delimitado mejor las vías nerviosas que conducen el prurito, el dolor, el tacto y tanto el prurito como el dolor.
En dicho artículo (que sólo se obtiene en resumen, si se quiere el extenso hay que comprarlo) ya se plantean vías nerviosas específicas para el prurito. En otro artículo que pongo a su disposición (y que se obtiene en texto completo), se explica con mayor detalle dicha diferenciación.
- Los nervios sensoriales primarios se clasifican en 3 grupos: nervios Aβ, Aδ y C, dependiendo de su mielinización, diámetro y velocidad de conducción. Los nervios Aδ y C están principalmente implicados en la conducción de la sensación térmica y dolor / picazón, mientras que los nervios Aδ conducen la sensación táctil.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3694590/pdf/nihms480958.pdf
Continuing with the relationship Pruritus and Pain;
- New experimental findings have found in relation to Pruritus, new neurological pathways and specific Central Nervous System (CNS) centers, in addition to another neurotransmitter involved in this unpleasant feeling, the Gastrin Releasing Peptide (PLG)
- Before I believed by certain experimental evidences in humans and social animals, that Empathy had to do with the scrape secondary to Prurito, as a type of behavior of socially accepted solidarity.
- Empathy understood as the emotional behaviors that human beings and animals close (phylogenetically with our species as primates and rats), recognize and share among their peers. The part of the CNS that regulates them, is the Limbic System (SL); Specifically: Frontal and orbitofrontal cortex, cingulate cortex, amygdala, hippocampus, thalamus, mammillary bodies and fornix.
- Regarding the relationship between Pruritus and Pain, it must be remembered that SL is related to all types of emotions, not only the Empathy and the Scraping Empathic Conduct in the presence of Scratch in some similar, even without sensation of Pruritus. SL is also related to the feeling of well-being, euphoria and happiness; To unpleasant emotions such as depression, anguish and fear.
- The latter, anguish and fear, often decrease the pain threshold; So that annoying or non-painful stimuli for certain people, such as local pressure or dermal scratching, can in very susceptible subjects be perceived as Pain and not as Itching.
http://www.redalyc.org/pdf/1339/133912609008.pdf
Continuando con la relación Prurito y Dolor;
- Nuevos descubrimientos experimentales han encontrado en relación al Prurito, nuevas vías neurológicas y centros del Sistema Nervioso Central (SNC) específicos, además de otro neurotransmisor involucrado en esta sensación desagradable, el Péptido Liberador de Gastrina (PLG)
- Antes de creía por ciertas evidencias experimentales en humanos y animales sociales, que la Empatía tenía que ver con el rascado secundario a Prurito, como un tipo de comportamiento de solidaridad socialmente aceptado.
- La Empatía entendida como las conductas emocionales que los seres humanos y animales cercanos (filogenéticamente con nuestra especie como primates y ratas), reconocen y comparten entre sus semejantes. La parte del SNC que las regula, es el Sistema Límbico (SL); específicamente: Corteza frontal y orbitofrontal, corteza cingulada, amígdala, hipocampo, tálamo, cuerpos mamilares y fórnix.
- Respecto de la relación entre Prurito y Dolor, hay que recordar que el SL está relacionado con todo tipo de emociones, no sólo la Empatía y la Conducta Empática de Rascado ante la evidencia de Rascado en algún semejante, aún sin sensación de Prurito. El SL está también relacionado con la sensación de bienestar, euforia y felicidad; hasta emociones desagradables como la depresión, angustia y el miedo.
- Estos últimos, la angustia y el miedo, con frecuencia disminuyen el umbral de dolor; por lo que estímulos molestos o no dolorosos para ciertas personas, como presión local o rayado dérmico, pueden en sujetos muy susceptibles percibirse como Dolor y no como Prurito.
http://www.redalyc.org/pdf/1339/133912609008.pdf
Completing the information on the experimental evidence on Pruritus and Pain, I also comment:
- Recalling that the Limbic System(LS) is the part of the CNS that regulates the emotions and how in humans this behavior evolves socially and probably phylogenetically, deriving in the Conduct of Empathy,
- In social animals such as mice, Empathy is usually the result of an automatic activation of the neural circuits of the LS. In some cases, "The mouse sees another mouse scratching itself and then he thinks he also needs to live up to that behavior." This is imitation Empathy.
- In other cases, this same species of animal sees another similar to scratching. At the same time, almost instantaneously, his brain sends signals of Pruritus through the Gastrin Releasing Peptide (GRP) and explains in these cases the Scratch Conduct.
- These results suggest that the Contagious Itching is not derived from Empathy in all cases but rather from an automatic activation of the neural circuits, using GRP as a messenger.
https://www.nih.gov/news-events/nih-research-matters/socially-contagious-itching-hardwired-into-brain
Completando la información sobre las evidencias experimentales sobre Prurito y Dolor, también les comento:
- Recordando que el Sistema Límbico es la parte del SNC que regula las emociones y cómo en los seres humanos esta conducta evoluciona socialmente y probablemente en forma filogenética, derivar en la Conducta de Empatía,
- En los animales sociales como los ratones, la Empatía es habitualmente, el resultado de una activación automática de los circuitos neuronales del Sistema Límbico. En algunos casos, “El ratón ve a otro ratón rascándose y luego él cree que también necesita estar a la altura de dicha conducta". Esto es Empatía por imitación.
- En otros casos, esta misma especie de animal, ve a otro semejante rascarse. Al mismo tiempo, casi en forma instantánea, su cerebro envía señales de Prurito por medio del Péptido Liberador de Gastrina (PLG) y explica en estos casos la Conducta de Rascado.
- Estos resultados sugieren que la picazón contagiosa no se deriva de la empatía en todos los casos sino más bien de una activación automática de los circuitos neuronales, utilizando PLG como mensajero.
https://www.nih.gov/news-events/nih-research-matters/socially-contagious-itching-hardwired-into-brain
Very interesting discussion! One could also take cue from the IASP definition of pain, described as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage"; explained further as follows: "Activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain..." Indeed, "itchy" is listed in the full version of the McGill Pain Questionnaire amongst the descriptors. Thus, through this admittedly simplistic prism, one could perhaps argue that pruritus, being an unpleasant sensation, is a type of pain ?
http://www.iasp-pain.org/Taxonomy#Pain
Dear Saad S Nagi
Of course, from the beginning the discussion became very interesting, given the apparent ambivalence between the essence of Pruritus and Pain; Pain as an unpleasant sensation before a real or potential harmful and even imaginary stimulus, as in cases of anticipation of pain; And Pruritus, also as an unpleasant sensation and a type of low-intensity Pain.
Recent discoveries in the pathophysiology and neuroanatomy of Pruritus and Pain have found that while each sensation has its exclusive sensory pathway, both receptors and nerve fibers (prurinogens and algogenic) also share a part of these receptors and nerves.
Thank you very much for the reference that will provide us with more information and knowledge to continue arguing in this discussion network.
I add two more "globalizing" references.
regards
Jose Luis
Estimado Saad S Nagi
Cierto, desde el principio se puso muy interesante la discusión, dada la ambivalencia aparente entre la esencia del Prurito y Dolor; el Dolor como una sensación desagradable ante un estímulo nocivo real o potencial, e incluso imaginario, como en los casos de anticipación al Dolor; y el Prurito, también como una sensación desagradable y un tipo de Dolor de baja intensidad.
Los últimos descubrimientos en la fisiopatología y neuroanatomía del Prurito y del Dolor, han encontrado que si bien cada sensación tiene su vía sensorial exclusiva, tanto receptores como fibras nerviosas (pruriginógenos y algógenas): también comparten una parte de dichos receptores y nervios.
Muchas gracias por la referencia que nos proporcionará más información y conocimientos para seguir argumentando en esta red de discusión.
Agrego dos referencias más "globalizadoras".
Saludos
José Luis
Pruritus and pain are detected by the same sensory nociceptors C and Ad, as well as chronic pain, when pruritus is severe, it generates important distressing physical and psychoaffective disorders, given its therapeutic difficulty, in extreme cases and to be modified With the administration of some NSAIDs can be considered as a form of pain.
Dear Uria Guevara
According to your comment, it agrees in summary form with the same terms and arguments as my previous comment.
regards
Jose Luis
Estimado Uria Guevara
De acuerdo con su comentario, concuerda en forma resumida con los mismos términos y argumentos que mi comentario anterior.
Saludos
José Luis
Dear Dr José Luis García Vigil , it is a very interesting question followed with very interesting discussion!!!
Pruritus is defined as an unpleasant sensation that provokes the desire to scratch. Certain systemic diseases have long been known to cause pruritus that ranges in intensity from a mild annoyance to an intractable, disabling condition. Generalized pruritus may be classified into the following categories on the basis of the underlying causative disease: renal pruritus, cholestatic pruritus, hematologic pruritus, endocrine pruritus, pruritus related to malignancy, and idiopathic generalized pruritus.
Pruritus, or itch, is most commonly associated with a primary skin disorder such as xerosis, atopic dermatitis, urticaria, psoriasis, arthropod assault, mastocytosis, dermatitis herpetiformis, or pemphigoid. However, when a primary skin condition cannot be identified as the cause of pruritus, then a systemic or neuropathic cause must be sought.
Source: https://emedicine.medscape.com/article/1098029-overview
Dear Beemnet Mengesha Kassahun
Indeed, if no local cause of the pruritus is identified, it is necessary to make a very oriented search of other systemic causes of it, or paraneoplastic, or neuropathic manifestation.
Prevention is often done by avoiding substances, foods or medications that cause an adverse reaction to pruritus. In other occasions the cause by insufficiency of some organ, like the kidney, suprarenal or the liver, is only controlled or disappears improving the function of the affected organ, or eliminating the toxic substance that causes the pruritus, as it would be the case of the deposit of salts nitrogenated (urea) in the skin, in renal failure; the elimination of a blockage of the bile ducts or the use of ion exchange resins in case of deposit of bile salts in the skin; or use of mineralocorticoids in adrenal failure.
regards
Jose Luis
Dear Mittal Patel and Dhiaa Neama Jabbar
Welcome to this discussion network
Thank you very much dear Dr. José Luis García Vigil and you explanations are buying and definitely right.
I think there is a link between itching and pain. The skin is equipped with a set of nerve endings that transmit information about stimuli that may be harmful to the spinal cord and brain. A weak attack on those nerve endings results in itching, while a full-blown attack results in pain.
Dear Nihad Mohammed. Totally agree
Dear Ahmed Mahdi. Thank you for continuing the discussion
Greetings. Jose Luis
The skin contains some nerve cells that respond only to itch and others that respond only to pain. Others, however, respond to both, and some substances cause both itching and pain. If itch and pain are closely linked, however, the implications are huge.
If the itching and pain are unpleasant.
An interesting fact is that the pathogenesis of pruritus involves vasoactive amines, which produce a state of perivascular inflammation; inflammation that decreases with the use of anti-inflammatories such as NSAIDs.
Diseases treated by histamine:
- Skin allergies in young and old, severe itching.
- Eczema, most skin diseases accompanied by redness of the skin.
- Allergy and itching due to kidney and liver disease.
- Swelling due to allergic reactions in the face, especially in the morning
Benefits of antihistamines
- Very effective in eliminating allergy and itching.
- Eliminates itching and skin infections, and helps in the ability to sleep.
- Relieves pain and swelling in many cases.
- Helps in the treatment of insect bites.
- reduces the effects of psoriasis and eczema.
Dear Djaafar Zemali
I agree with you that there is also a beneficial effect of antihistamines due to a decrease in pruritus in the conditions where it is involved in its genesis to histamine and bradykinin.
regards Jose Luis
In my opinion, All kinds of sufferings are considered as pain only.
Regards
Dr. Kamath Madhusudhana
I don't know, but in my opinion, it's a kind of alert from our body !
Yes, it is a warning sign of something that bothers and damages organs and tissues
Itch is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience. Modern science has shown that itch has many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response patterns are different. Pain creates a withdrawal reflex, whereas itch leads to a scratch reflex.
Unmyelinated nerve fibers for itch and pain both originate in the skin; however, information for them is conveyed centrally in two distinct systems that both use the same nerve bundle and spinothalamic tract.
From Nature magazine
Once thought to be a low-level form of pain, itch is instead a distinct sensation with a dedicated neural circuit linking cells in the periphery of the body to the brain, a study in mice suggests.
Yes, it is atype of pain
Pruritus simply means itching. It can be associated with a number of disorders, including dry skin, skin disease, pregnancy, and rarely, cancer.
Dear Sajda Taha Mahmood
Although his response does not directly differentiate if pruritus is a type of pain; if I agree with the causes and general management of pruritus.
Thank you Jose Luis
Dear Khansaa Azeez Obayes Al-Husseini
Totally agree with your arguments and your response
Regards
José Luis
Dear Djaafar Zemali
It is true that recent information and in the experimental model of mice, an additional specific pathway for the transmission of the sensation originated by the pruritus has been demonstrated, that by the way, if they have a common neural pathway; as I mentioned in detail in my update 2 years ago (vide supra)
Regards
José Luis
Dear Alaa Raheem Kazim
Totally agree with your arguments and your response
Regards
José Luis
Itch (also known as pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience. Itch has many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response patterns are different.
- Badges
- Science topic
- Similar topics
- Medicine
- Physiology