Pschogenic pruritus/Pruritul psihogen

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From: Bulletin of Integrative Psychiatry(Vol. 19, Issue 4.)
Publisher: Institute of Psychiatry Socola, Iasi
Document Type: Report
Length: 5,922 words
Lexile Measure: 1710L

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Abstract: 

Perceived as an itching, ranging in intensity from one person to another, pruritus is a frequent symptoms of dermatological diseases. Pruritus may be considered a functional disorder in which the psychogenic factors play an important role in its onset. Skin diseases are significantly conditioned by stress and emotions, those influences on the skin beeing mediated by the nervous system including the autonomic, immune or hormonal system. The diagnosis of psychogenic pruritus is determined after eliminating any other causes of pruritus, so it is a diagnosis of exclusion. The quality of life to a patient with psychogenic pruritus in influenced in a negative way just because of the impact created by its awareness of his skin symptoms, expressed by itching, scratching lesions, sometimes quite severe marks. There is no specific treatment in such situations. The optimal treatment is the etiologic one, by eliminating as much as possible the triggering factors/condition.

KEYWORDS

functional disorder, itch, neuropeptide, interleukin

Perceputa ca o mancarime, variind in intensitate de la o persoana la alta, pruritul este un simptom frecvent in bolile dermatologice. Pruritul poate fi considerat o tulburare functionala, in care factorii psihogeni joaca un rol important in debutul acesteia. Bolile de piele sunt conditionate, in mod semnificativ, de stres si de emotii, acestea influentand pielea prin sistemul nervos, inclusiv prin sistemul autonom, imunitar sau hormonal. Diagnosticul de prurit psihogen este stabilit dupa eliminarea oricaror alte cauze, fiind, prin urmare, un diagnostic de excludere. Calitatea vietii unui pacient cu prurit psihogen este influentata negativ din cauza impactului creat de constientizarea simptomelor cutanate exprimate de prurit si escoriatii, uneori, destul de severe. Nu exista niciun tratament specific in astfel de situatii. Tratamentul optim este unul etiologic, prin eliminarea cat mai mult posibil a factorilor declansatori.

CUVINTE-CHEIE

tulburare functionala, prurit, neuropeptide, interleukina

Full Text: 

OVERVIEW

Although it is one of the most frequent symptoms of dermatological diseases, pruritus often triggers difficulties regarding the therapeutic cures or its belonging to a particular pathology, as it is the clinical expression of internal suffering, apart from the psychical one, situation in which we deal with psychogenic pruritus.

In the psychiatric literature, it is included in the category of somatoform disorders, which refers to skin conditions that are not fully explained by a known dermatologic disease; the members of the French society of psycho- dermatology prefer the functional disorder terminology, avoiding the phrase "psychogenic pruritus", precisely because of the various interpretative possibilities that would negatively affect the quality of life in patients with such disorders.

Pruritus is perceived as an itching, ranging in intensity from one person to another, from a simple to a painful irritation that dominates the behavior in the case of individuals with psychiatric disorders such as depression, anxiety, psychoneurosis, etc. Somatoform itching is part of a family of functional mucocutaneous skin disorders with psychogenic pain, paresthesia, vulvodynia, stomatodynia, glossodynia. (1)

In women, the vulva and the perianal itching are recognized as manifestations of psychogenic pruritus and are sometimes caused by stress, although this cause is probably overrated, because there first should be excluded the occult reversible causes such as oxyuriasis, drug dermatitis, candidiasis, neoplasia, nocturnal pruritus outbreaks accompanied by itching and sweating, often leading to anxiety. Such episodes of pruritus have been reported in people who are waiting for a transplant. It is obvious that patients who experience severe persistent pruritus, become depressed, and this reduces the threshold of itching, completing a vicious circle of pruritus, depression and even more intense itching. (2)

The members of the French society of psychodermatology define pruritus as an itch, a functional disorder, in which the psychogenic factors play an important role in its onset. This requires 10 diagnostic criteria, three of which are mandatory and seven are optional (Table 1).

The correlation between cutaneous symptoms and brain impulses

Approximately 30 % of the patients with skin diseases were reported to have mental disorders and psychosocial disparities (Kesler et Al., 2005). The prevalence of mental disorders among these patients is 25-30 %, with higher rates in patients with acne, itching rashes, alopecia and herpes simplex (Picardi, Abena, Melchor, Puddu and Pasquini, 2000). (4)

It is known that the skin, as well as the brain, has the same embryological origin--the neuroectoderm, while the pruritus can be considered the element that determines the complex but complicated relationship between the two organs.

The skin is the most "psyched" sensory organ because, at this level reactions which are mediated by the neurovegetative system occur, while the pathological mental states and processes are properly conceived. In the skin-psychic correlation, the NICE model is asserted (neuro-immuno-cutaneous-endocrine network), consisting of four systems interconnected through a common substrate of neuropeptides, cytokines, glucocorticoids and other effector molecules. The combination between the nervous system and skin diseases is reflected by the exacerbation of pruritic skin lesions of psoriasis, acne, hives, eczema and many more, after stressful events (5).

In recent years, the brain areas responsible for itching have been elucidated. The cingulate cortex in particular appears to be an important area of the brain involved in processing the sensation of itching. The cingulate cortex is activated significantly in patients with atopic dermatitis after the administration of histamine and its activation is correlated with the severity of the disease. The deactivations of the cingulate cortex after excoriation in healthy subjects was also determined. The anterior cingulate cortex is involved in the modulation of emotional and cognitive activity and it can provide a physiological ground on how the mood and motivation can influence the perception and processing of itching. (6)

Skin diseases are significantly influenced by stress and emotions. The great dermatologist and psychiatrist Griesemer studied the effect of emotions on dermatological disorders (pruritus, rosacea, lichen planus, atopic dermatitis, alopecia areata, seborrheic dermatitis, etc.), showing that the influences of stress and emotions on the skin are mediated by the nervous system, including the autonomic, immune or hormonal system. Also, stress can cause or enhance anxiety disorders or depression in susceptible persons. (4)

Fjellner and Arnetz have studied the psychological anticipatory factors during emotional stress. The exposure of healthy volunteers to mental stress activates the psychoneuroendocrin system without other skin conditions, sensitive to intradermal injections of histamine. The differences between subjects were obvious and partially related to the urinary level of epinephrine. Epinephrine seems to have had a suppressive effect on itching and enhanced the effects in response to the light signal. The pulse rate was positively correlated with the intensity of the light signal response. During the test, the subjects relaxed themselves by listening to music and, after that, they were exposed to mental stress, a test being given to them with words written in bold and they were urged to solve arithmetic problems for 50 minutes, while the changes in the pulse rate or systolic and diastolic blood pressure were being monitored. The tests were followed by other 40 minutes of relaxation. The results confirmed that pruritus is influenced by subjective psychological stress, although there were great individual variations. Many of the various psycho-biological mechanisms, in which the skin diseases became chronic, seem to be strongly associated with psychological and behavioral influences. (7)

Mechanisms involved in psychogenic pruritus

The itching sensation, described above, is induced by the stimulation of loose nerve endings in the superficial layers of the skin, the sensory apparatus being located on the dermoepidermal junction and the fibers that transmit this sensibility belong to the spino-thalamic lateral tissue (type C demyelinated fibers). This is accompanied by activation of the anterior cortex and predominantly ipsilateral activation of additional areas of movement and the inferior parietal lobe, followed by excoriation, which reflects the fact that "the one that itches is the brain, not the skin" (8). Itching can be caused by a number of physical stimulichanges in temperature, superficial touches, chemical- histamine, kinin, opioid peptides, vasoactive intestinal polypeptide (VIP), serotonin, prostaglandin F1, but also emotional factors. The autonomic nervous system plays a secondary role in the mechanism of pruritus, fact demonstrated by the observation that patients that underwent sympathectomies have a normal sensitivity to pruritic stimuli. (9)

An important element for conveying the sensation of itching is neurokinin-1, receptor found in the cutaneous nerves and in the neurons of the posterior horn, as recently shown in rats, indicating that neurokinin/neuropeptide P can play the role of the spinal transmitter of the itching. (10)

Classic inflammatory mediators, such as bradykinin, serotonin, and acidic pH, sensitize the nociceptors. Acute sensitization can be achieved through mediators of inflammatory cells, such as interleukins, but their acute effects can not account for the long lasting changes of neuronal sensitivity observed in inflammatory processes. Usually, gene expression induced by trophic factors, for example, the neuronal growth factor (NGF) has been shown to play a major role, constantly increasing the neuronal sensitivity. NGF is released into the periphery, it specifically attaches to the TrkA receptors on nociceptive nerve endings and, through a retrograde axonal path, it reaches the dorsal root ganglion, where the gene expression in neuropeptides and molecular receptors is increased. The trophic factors stimulate the formation of nerve fiber, thereby changing the morphology of sensory neurons. Similar mechanisms underlie the chronic itch and chronic pain (11).

Interleukin 2 has a proven role in inducing pruritus. It has been shown that direct injection of this cytokine in healthy subjects, as well as in those with atopic dermatitis led to an itchy sensation. It was also found that the concentration is higher in patients with pruritic lesions than in those without such lesions. Therefore, therapeutic measures which inhibit IL-2 (PUVA therapy, tacrolimus, thalidomide) are effective in treating pruritus which is nonresponsive to conventional treatments. (12)

In a study of histamine-induced pruritus, the mental trauma has enhanced the itching sensation and its duration. The duration of pruritus was reported to be higher in depressed subjects during exposure to stress (Fjellner and Arnetz, 1985, Fjellner et al. 1985). Another study on pruritus in psoriasis, atopic dermatitis and chronic idiopathic urticaria showed a correlation between the severity of pruritus and the intensity of depressive symptoms (Gupta et al. 1994). (13)

In stress, the raised levels of some neuromediators-B endorphins exacerbate the skin lesions. In practice, every dermatologist experienced associations between external stressors that induced cutaneous symptoms, hard to fit into a specific cutaneous pathology and, therefore, making it difficult to choose an effective therapeutic conduct.

Opioids modulate the itching sensation, both peripherally and centrally. The stimulation of the mu opioid receptors exarcebates itching, while the stimulation of the kappa receptors and the obstruction of mu receptors suppress the itching. (14)

Some studies suggest that ordinary hyperhidrosis of the palms and soles is increased due to stress and has no connection with chronic anxiety. (15)

Psychogenic pruritus vs. non-psychogenic pruritus

Radmanesh & Shafiei revealed the features that differentiate the psycho-pruritic disorders from the pruritic ones: the episodes are chronic and recurrent with short, intense and uncontrollable itching phenomena for a period varying from a few hours to several days. There may be encountered feelings of pleasure during the scratching and satisfaction when the itching is over; the itching sensation in neurotic excoriation (NE) and psychogenic pruritus may or may not be found in the behaviour, which shows that the onset of pruritus in any segment of the body can lead to itching throughout the body; the pruritic sequences can be bizarre from the onset to the end: they can begin and end abruptly; the pruritic episodes are more frequent while resting or sleeping; the self-inflicted injuries, such as excoriations and scratches, with subsequent bleeding and crusting are common in chronic lichen simplex, neurotic excoriations and nodular prurigo; the patients have a poor response to any known antipruritic agents; the patients may be introverted and can present a recent history of psycho-emotional stress. (3)

Neither psychogenic pruritus nor organic itching can be found in a pure form, often these types of pruritus coexist. The interaction between chronic and psychic itching is complex, but it can be summarized in three main groups:

* pruritic diseases with psychiatric sequelae (endogenous eczema, nodular prurigo, chronic lichen simplex, psoriasis, dermatitis herpetiformis, Darier disease, pruritic epidermolysis bullosa, metabolic-uremic pruritus, chronic liver diseases, hyperthyroidism, pruritus in menopause, HIV, parasites, malignancies--lymphoma, polycythemia rubra vera--peripheral neuropathy, multiple sclerosis);

* pruritus worsened by psychosocial factors (eczema, nodular prurigo, chronic urticaria, pruritus in the genital region, senile pruritus);

* psychogenic disorders causing pruritus (itchy somatoform disorder/functional disorder, dermatitis factitus, impulse control disorder, neurotic excoriation, psychosis-illusion of parasites, schizophrenia with tactile hallucinations). (6)

The diagnosis of psychogenic pruritus is determined after eliminating any other causes of the disorder; although it is difficult and requires a thorough corroboration between clinical and paraclinical elements, one can not label a patient as having a mental illness which triggers the itching sensation, because it produces a negative psycho-emotional impact on the person and would further enhance his suffering. Indeed, in the history of such a patient there can be found various disorders, conflicts, aberrant behavior etc. Therefore, psychogenic pruritus remains a diagnosis of exclusion, established after excluding the other forms of pruritus.

What distinguishes it from the other forms of pruritus is the fact that after research, there is not revealed any systemic or cutaneous cause that could induce it and that its intensity is directly correlated with the magnitude of some neuropsychological conditions. The patients describe the symptoms by exaggerating, mentioning unusual locations or strange triggering factors. The scratch marks are disproportionate to the skin features, often leading to pathomimesis. (16)

The quality of life and therapeutic conduct

In practice, it is noticeable that the negative impact created by the patient's awareness of his skin symptoms, expressed by itching, scratching lesions, and, sometimes, quite severe marks, has its starting point in the psychic area. His quality of life is negatively influenced, causing him great discomfort in interpersonal relationships and even with his own family. He feels isolated, pitied and, eventually, he is led towards introversion, all these experiences further enhancing the skin lesions that he has.

The patients' education and especially the one of their family members regarding the interaction between skin disease, mind and body, as well as the information about the medical or non-pharmacological treatment, represents the key to successfully monitoring and diagnosing the patients. Learning about the effects of drugs, even the secondary ones, their dose and interaction with other drugs are also important. With respect to nonpharmacological ways of treatment, the patient's education in accessible terms is also the key. Therefore, the compliance is optimal when the patient and his family are well informed, when they are monitored either by phone or by regular check-ups, all of these motivating the patient and his family. (4)

Based on Fried's proposals regarding the therapeutic approach of dermatological diseases with psychosomatic determinism, the conduct is organized on three levels: lesionally, in which conventional dermatological therapy is used, emotionally, based on doctor-patient cooperation, providing emotional support, empathic and cognitive which aims at removing erroneous beliefs about causes and infectiousness. (5)

The optimal treatment is the etiologic one, by eliminating as much as possible the triggering factors/condition. When the cause is undetected, a local symptomatic treatment must be administered, which aims at administration of antihistamines (especially anti-H1), nonspecific desensitization, local applications of corticosteroid. (2)

The psychotropic medication used includes antidepressants, antipsychotics and anxiolytics, activating on the skin level by inhibiting the protein kinase C, which catalyzes the phosphorylation of cutaneous protein substrates. Not long ago, mirtazepine--both a noradrenergic and serotonergic antidepressant has been promoted for intractable itching, including the itching in the skin lymphoma with B cells. (2)

The remission of pruritus was also induced through PUVA therapy (photochemotheropy with UV type A), method whose mechanism of action is the inhibition of DNA through the formation of stable links between pyrimidine bases and through reducing the number of epidermal cells, Langerhans type, resulting in a decrease of inflammatory cells.

Whatever the nature of pruritus, for an effective monitoring and therapeutic approach, interdisciplinary collaborations between dermatologists, psychiatrists, internists and psychologists are required in order to help the patients and their families.

Laura Gheuca-Solovastru--MD, PhD, Assistant Professor, Dep. Dermatovenereology; University of Medicine and Pharmacy "Grigore T. Popa", Iasi, Senior dermatovenerolog, Dermatovenereology-Clinic; County Clinical Emergency Hospital "Sf. Spiridon", Iasi, Romania

Adriana Patrascu--MD, resident in dermato vene rology, Dermato venereology Clinic; County Clinical Emergency Hospital "Sf. Spiridon", Iasi, Romania

Alina Stincanu--MD, Phd, Specialist dermatovenerology Dermatovenereology Clinic; County Clinical Emergency Hospital "Sf. Spiridon", Iasi, Romania

Laura Statescu--MD, PhD, Assistant Professor, Dep. Dermatovenereology; University of Medicine and Pharmacy "Gr. T. Popa", ", Iasi; Specialist dermato vene rology, Dermatovenereology Clinic; County Clinical Emergency Hospital "Sf. Spiridon", Iasi, Romania

Romeo Petru Dobrin--M.D., Ph.D., Assistant Professor University of Medicine and Pharmacy "Gr. T. Popa", Dept. of Psychiatry, Senior Psychiatrist, Clinical Psychiatric Hospital "Socola", Iasi

Dan Vata--MD, PhD, Assistant Professor, Dep. Dermatovenereology; University of Medicine and Pharmacy "Gr. T. Popa", ", Iasi; Specialist dermato vene rology, Dermatovenereology Clinic; County Clinical Emergency Hospital "Sf. Spiridon", Iasi, Romania

ACKNOWLEDGEMENTS AND DISCLOSURE

The authors declare that they have no potential conflicts of interest to disclose

REFERRENCES:

(1.) Laurent Misery, Sonja Stader, Pruritus, London, 2010, 35:223-227;

(2.) Tony Burns, Stephen Breathnach, Neil Cox, Christopher Griffiths, Rook's Textbook of Dermatology, Eighth edition, 2010, Vol I, 21:12;

(3.) Laurent Misery, Sophie Alexandre, Sabine Dutray et al., Functional Itch Disorder or Psychogenic Pruritus: Suggested Diagnosis Criteria From the Franch Psychodermatology Groups Acta Derm Venerol 2007; 87:341-344, www.medicaljournals.se/acta/content/;

(4.) A. Philip, D. Shenefelt, MD, MS, Management of Psychodermatologic Disorders, Dermatology Nursing, october 2010, http://www.medscape.com/viewarticle/730033_2;

(5.) Justin Dumitru, C. Diaconu, Oana Andreia Coman, Vasile Bene a, Tratat de terapeutica demato-venerologica, Editura Viata Medicala Romaneasca, Bucuresti 2002, 1.2:108-118;

(6.) Hong Liang Tey, MD, Joanna Wallengren, MD and Gil Yosipovitch, MD, Psychosomatic factors in pruritus, Clinics in Dermatology, Volume 31, Issue 1:31-40, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3690364;

(7.) Alan Stoudemire, MD & Barry S. Fogel, MD, Medical Psychiatric practice, volume I, Americam Psychiatric Press, INC, Washington, DC, 2005, p. 293;

(8.) R. Paus, M. Schmelz, T.Biro, M. Steinhoff, Frontiers in pruritus research: scratching the brain for more efective itch therapy. J.Clin Invest, 2006; 116: 1174-1185,http://books.google.ro;

(9.) Dan Forsea, raluca Popescu, Catalin Mihai Popescu, Compendiu de dermatologie si venerologie, Editura tehnica, Bucuresti, 1996, 10: 54;

(10.) Ulrike Raap, Sonja Stander, Martin Metz, Pathophysiology of Itch and New Treatments, Current Opinion in Allergy and Clinical Immunology, october 2011, http://www.medscape.com/viewarticle/749608

(11.) Stephen McMahon, Martin Koltzenburg, Irene Tracey, Dennis C. Turk, Wall & Melzack's Textbook of Pain: Expert Consult--Online, sixth edition, 21.17.

(12.) http://en.wikipedia.org/wiki/Interleukin_2#Pruritus_.28itch.29;

(13.) James L. Levenson, M.D, Textbook of Psychosomatic Medicine, First Edition, American Psychiatric Publishing, Inc, Washingtoniazisului DC, p.634;

(14.) David F Butler, MD; Chief Editor: Dirk M Elston, MD, Pruritus and Systemic Disease, http://emedicine.medscape.com/ article/ 1098029-followup.

(15.) J.A.A. Hunter, John Salvin, Mark Dahl, Clinical Dermathology, Third Edition, p. 299.

(16.) Gheorghe Bucur, dana Angela Opris, Boli dermato venerice, enciclopedie, Editia a II-a, Editura Medicala Nationala, Bucuresti, 2002, p. 604.

Correspondence:

Dan Vata

Clinica Dermato-enerologie, Spitalul "Sf. Spiridon", str. Ciurchi nr. 1 1 1, Iasi,

Tel: 0741084264

E-mail: danvata@yahoo.com

Date of Submission: August, 27, 2013/ Acceptance: November, 12, 2013

ASPECTE GENERALE

Desi este cel mai frecvent simptom din categoria afectiunilor dermatologice, pruritul induce, adesea, dificultati in privinta mijloacelor terapeutice si incadrarii int-o patologie anume, deoarece este expresia clinica a unor suferinte interne, inclusiv psihice, situatie in care ne confuntam cu pruritul psihogen.

In literatura psihiatrica, acesta este inclus in categoria tulburarilor somatoforme, ce includ afectiuni ale pielii ce nu sunt pe deplin explicate de o boala dermatologica cunoscuta; membrii Societatii franceze de Psiho dermatologie prefera terminologia de tulburare functionala, evitand sintagma de prurit psihogen, tocmai din cauza diverselor posibilitati interpretative, ce ar influenta negativ calitatea vietii pacietilor cu astfel de tulburari.

Pruritul este perceput ca o senzatie de mancarime, de o intensitate ce variaza de la o persoana la alta, de la o simpla iritatie pana la o senzatie dureroasa care domina comportamentul, in cazul indivizilor cu afectiuni psihiatrice, precum depresia, anxietatea, psihonevrozele etc.

Mancarimea somatoforma face parte dintr-o familie de tulburari functionale muco-cutanate, alaturi de durerea cutanata psihogena, parestezii, vulvodinie, stomatodinie, glosodinie. (1)

La femei, pruritul vulvar si cel perianal sunt recunoscute ca manifestari ale pruritului psihogen si sunt, uneori, determinate de stres, cu toate ca aceasta cauza este, probabil, supraevaluata, trebuind excluse cauzele oculte, reversibile, ca oxiuroza, dermatita medicamentoasa, candidoza, neoplaziile, atacurile de prurit nocturn, insotit de senzatia de mancarime si transpiratii, toate acestea ducand, de multe ori, la anxietate. Astfel de episoade de prurit au fost raportate si la persoane care asteapta un transplant. Este evident ca pacientii care se confrunta cu prurit persistent sever devin depresivi si acest lucru reduce pragul senzatiei de mancarime, completand un cerc vicios al pruritului, depresiei si mancarimii mai intense. (2)

Membrii Societatii Psiho-dermatologice franceze definesc pruritul ca o mancarime, o tulburare functionala, in declansarea careia factorii psihogeni joaca un rol deosebit de important. Pentru aceasta sunt necesare zece criterii de diagnostic, dintre care trei sunt obligatorii, iar sapte, optionale (tabel 1).

CORELATIA SIMPTOMELOR CUTANATE CU IMPULSURILE CEREBRALE

Aproximativ 30 % dintre pacientii cu afectiuni dermatologice au fost raportati ca avand tulburari psihice si deficite psihosociale (Kesler et al, 2005). Prevalenta tulburarilor psihice in randul acestor pacienti este de 25-30 %, cu rate mai mari la pacientii cu acnee, prurit, urticarie, alopecie si herpes simplex (Picardi, Abenia, Melchi, Puddu si Pasquini, 2000). (4)

Se cunoaste ca pielea, la fel ca si creierul au aceeasi origine embriologica--neuroectodermul, iar pruritul poate fi considerat elementul ce stabileste legatura complexa, dar complicata dintre cele doua organe.

Pielea este organul de simt cel mai psihi%at, deoarece, la nivel cutanat, au loc reactii mediate de sistemul neurovegetativ, proiectandu-se, astfel, stari psihice si procese patologice propriu-zise. In corelatia piele--psihic, se remarca modelul NICE (reteaua neuro-imuno-cutaneo-endocrina, constituita din patru sisteme interconectate printr-un substrat comun de neuropeptide, citokine, glucocorticoizi si alte molecule efectoare. Asocierea sistem nervos--boli dermatologice se concretizeaza prin exacerbarea leziunilor tegumentare pruriginoase din psoriazis, acnee, urticarie, eczema s.a., dupa evenimente stresante (5).

In ultimii ani, au fost elucidate zonele din creier responsabile de senzatia de mancarime. Cortexul cingular, in special, pare a fi o zona importanta din creier, implicata in prelucrarea acestei senzatii de mancarime. Cortexul cingular este activat, in mod semnificativ, la pacientii cu dermatita atopica, dupa administrarea de histamina, activarea fiind corelata cu severitatea bolii. De asemenea, s-a constatat dezactivarea cortexului cingular dupa excoriatii la subiectii sanatosi. Cortexul cingular anterior este implicat in modularea activitatii emotionale si cognitive, putand oferi o baza fiziologica referitoare la modul in care starea de spirit si motivatia pot influenta perceptia si prelucrarea senzatiei de mancarime. (6)

Afectiunile cutanate sunt influentate semnificativ de stres si emotii. Marele dermatolog si psihiatru Griesemer a studiat efectul emotiilor asupra afectiunilor dermatologice (prurit, rozacee, lichen plan, dermatita atopica, alopecie areata, dermatita seboreica etc.), aratand ca influentele stresului si emotiilor asupra pielii sunt mediate de sistemul nervos, inclusiv cel autonom, sistemul imunitar si cel hormonal. De asemenea, stresul poate determina sau agrava tulburari de anxietate sau depresie la persoanele susceptibile. (4)

Fjellner si Arnetz au studiat factorii predictori psihologici in timpul stresului emotional. Expunerea voluntarilor sanatosi la un stres psihic activeaza sistemul psiho-neuro-endocrin, fara alte efecte cutanate, sensibile la injectarile intradermice de histamina. Diferentele dintre subiecti au fost evidente si partial legate de nivelul urinar al epinefrinei. Aceasta pare sa fi avut un efect supresiv asupra senzatiei de mancarime si a consolidat efectele, ca raspuns la semnalul luminos. Frecventa pulsului a fost corelata pozitiv cu intensitatea raspunsului la semnalul luminos. In timpul perioadei de test, subiectii s-au relaxat ascultand muzica, apoi au fost expusi la stres psihic, oferindu-li-se un test cu cuvinte colorate in contrast, fiind, in acelasi timp, indemnati sa rezolve probleme aritmetice, timp de 50 minute, in acest sens, monitorizandu-li-se modificarile pulsului si presiunii arteriale sistolice si diastolice. Acestea au fost urmate de inca 40 minute de relaxare. Cu toate ca au existat mari variatii individuale, rezultatele au confirmat ca pruritul este influentat de stresul psihic subiectiv. Multe dintre diferitele mecanisme psiho-biologice, in care bolile de piele au devenit cronice, par sa fie puternic asociate cu diverse influente psihologice si comportamentale. (7)

MECANISME IMPLICATE IN PRURITULUI PSIHOGEN

Senzatia de mancarime, descrisa anterior, este indusa de stimularea terminatiilor nervoase libere de la nivelul straturilor superficiale ale pielii, aparatul senzorial fiind localizat la jonctiunea dermo-epidermica, iar fibrele care transmit aceasta sensibilitate apartinand fascicolului spino-talamic lateral (fibre amielinice de tip C). Aceasta este insotita de activarea cortexului anterior si, predominant, ipsilaterala a zonelor motorii suplimentare si a lobului parietal inferior, fiind urmate de excoriatii, ceea ce reflecta faptul ca "cel care mananca este creierul, nu pielea" (8). Pruritul poate fi produs de o serie de stimuli fizici--modificari de temperatura, atingeri superficiale, chimici--histamina, kinine, peptide opioide, polipeptidul vasoactiv intestinal (VIP), serotonina, prostaglandina F1, dar si de factori emotionali. In mecanismul pruritului, sistemul nervos vegetativ are rol secundar, fapt argumentat de observatia ca pacientii simpatectomizati pastreaza o sensibilitate normala fata de stimulii pruriginosi. (9)

Un element important pentru transmiterea senzatiei de mancarime il constituie neurokinina-1, receptor exprimat la nivelul nervilor cutanati si neuronilor cornului dorsal, asa cum s-a aratat recent la sobolan, indicand faptul ca neurokinina/neuropeptidul P poate juca rolul de transmitator spinal al pruritului. (10)

Mediatorii clasici ai inflamatiei, precum bradichinina, serotonina, dar si PH-ul acid, sensibilizeaza nociceptorii. Sensibilizarea acuta poate fi realizata prin mediatori ai celulelor inflamatorii, cum sunt interleukinele, insa efectele acute ale acestora nu pot explica schimbarile de durata ale sensibilitatii neuronale, observate in procesele inflamatorii. De regula, expresia genelor induse de factori trofici, de exemplu, factorul de crestere neuronal (NGF), s-a dovedit a juca un rol major, crescand constant sensibilitatea neuronala. NGF este eliberat in periferie, se leaga specific de receptorii TrkA de la nivelul terminatiilor nervoase nociceptive si, pe cale axonala retrograda, ajunge la ganglionul radacinii dorsale, unde expresia genelor in neuropeptide si receptori moleculari este crescuta. Factorii trofici stimuleaza formarea de fibre nervoase, schimband, astfel, morfologia neuronilor senzitivi. Mecanisme similare stau la baza pruritului cronic si a durerii cronice (11).

Interleukina 2 are rol documentat in inducerea pruritului. S-a demonstrat faptul ca injectarea directa a acestei citokine la subiectii sanatosi, precum si la cei cu dermatita atopica a dus la o senzatie de mancarime. S-a constatat, de asemenea, ca aceasta se gaseste in concentratie mai mare la pacientii cu leziuni pruriginoase decat la cei fara astfel de leziuni. De aceea, masurile terapeutice ce inhiba Il-2 (PUVA terapia, tacrolimus, talidomida) sunt eficiente in tratarea pruritului nonresponsiv la tratamentele clasice. (12)

Intr-un studiu despre pruritul indus de histamina, trauma psihica a accentuat senzatia de mancarime si durata acesteia. Durata pruritului a fost raportata ca fiind mai mare la subiectii depresivi, in timpul expunerii la stres (Fjellner si Arnetz, 1985; Fjellner si colab., 1985). Un alt studiu asupra pruritului in psoriazis, dermatita atopica si urticarie cronica idiopatica a aratat corelatia dintre severitatea pruritului si intensitatea simptomelor depresive (Gupta si colab., 1994). (13)

In conditii de stres, concentratiile crescute ale unor neuromediatori-B endorfine exacerbeaza leziunile cutanate. Fiecare dermatolog s-a confruntat, in practica curenta, cu asocieri intre factorii de stres externi ce induceau simptome cutanate, greu de incadrat intr-o patologie cutanata specifica, fiind, prin urmare, greu de adoptat o conduita terapeutica eficienta.

Opioidele moduleaza senzatia de prurit atat periferic, cat si central. Stimularea receptorilor opioizi mu accentueaza pruritul, in timp ce stimularea receptorilor kappa si blocarea receptorilor mu suprima pruritul. (14)

Unele studii sugereaza ca banala hiperhidroza a palmelor si talpilor este accentuata ca urmare a stresului si nu are nicio legatura cu anxietatea cronica. (15)

PRURIT PSIHOGEN VERSUS PRURIT NONPSIHOGEN

Radmanesh & Shafiei au relevat particularitatile ce diferentiaza tulburarile psiho-pruriginoase de cele pruriginoase propriu-zise: episoadele sunt cronice si recidivante, cu scurte, intense si incontrolabile fenomene de prurit pe o durata variabila, de la cateva ore la cateva zile. Pot fi intalnite si sentimente de placere in timpul scarpinatului si satisfactii la terminarea senzatiei de mancarime; senzatia de mancarime in excoriatiile nevrotice (NE) si pruritul psihogen pot fi sau nu regasite in comportament, ceea ce arata ca declansarea pruritului in orice segment al corpului poate duce la o senzatie de mancarime in intreg organismul; secventele pruriginoase pot fi bizare de la debut pana la final: acestea pot sa inceapa si sa se termine brusc; episoadele pruriginoase sunt mai frecvente in repaus sau in somn; leziunile autoprovocate, ca excoriatii si eroziuni, cu sangerari si, ulterior, cruste sunt comune in lichenul cronic simplex, excoriatii neurotice si prurigo nodular; pacientii prezinta un raspuns slab la agentii antipruriginosi cunoscuti; pacientii sunt introvertiti si pot prezenta un istoric recent de stres psihoemotional. (3)

Nici pruritul psihogen, nici cel organic nu se regasesc intr-o forma pura, adesea aceste categorii de prurit coexistand. Interactiunea dintre pruritul cronic si cel psihic este complexa, dar poate fi sintetizata in trei grupe principale:

* boli pruriginoase cu sechele psihiatrice (eczeme endogene, prurigo nodular, lichen cronic simplex, psoriazis, dermatita herpetiforma, boala Darier, epidermoliza buloasa pruriginoasa, tulburari metabolice--prurit uremic, boli cronice ale ficatului, hipertiroidism, pruritul din menopauza, HIV, parazitoze, afectiuni maligne--limfom, policitemia rubra vera-neuropatia periferica, scleroza multipla);

* pruritul agravat de factori psihosociali (eczeme, prurigo nodular, urticaria cronica, pruritul din regiunea genitala, pruritul senil);

* tulburari psihogene cauzatoare de prurit (tulburare somatoforma cu prurit/tulburare functionala, dermatita factitus, tulburare in controlul impulsurilor, excoriatie neurotica, psihoze--iluzia de parazitoze, scizofrenia cu halucinatii tactile). (6)

Diagnosticul de prurit psihogen se stabileste in urma eliminarii celorlalte cauze de prurit; desi este dificil si impune o coroborare minutioasa intre elementele clinice si cele paraclinice, nu se poate eticheta un pacient ca avand drept cauza declansatoare o afectiune psihica, care ii induce senzatia de mancarime, deoarece ar produce un impact psihoemotional negativ pentru persoana in cauza si i-ar accentua si mai mult suferinta. Intr-adevar, in istoricul unui astfel de pacient, se regasesc diverse tulburari psihice, stari conflictuale, comportament aberant etc. Asadar, pruritul psihogen ramane un diagnostic de excludere, stabilit dupa eliminarea celorlalte forme de prurit.

Ceea ce il deosebeste de celelalte forme de prurit consta in aceea ca, in urma investigatiilor facute, nu se deceleaza nicio cauza sistemica sau cutanata ce l-ar putea induce si ca intensitatea acestuia este direct corelata cu amploarea unor stari neuropsihice. Pacientii descriu simptomatologia in mod exagerat, cu localizari neobisnuite, cu factori trigger ciudati. Semnele de grataj sunt disproportionale cu aspectul pielii, imbracand, frecvent, caracter de patomimie. (16)

CALITATEA VIETII SI CONDUITA TERAPEUTICA

In practica curenta, este vizibil impactul negativ creat de constientizarea de catre pacient a faptului ca simptomatologia lui cutanata, exprimata prin prurit, leziuni de grataj, uneori, eroziuni destul de semnificative, isi are punctul de plecare in sfera psihica. Calitatea vietii lui este influentata nefavorabil, provocandu-i disconfort in relatiile interumane, chiar si in cadrul familiei. Se simte izolat, compatimit si, in cele din urma, ajunge la introvertire, toate aceste trairi exacerband si mai mult leziunile cutanate pe care le are.

Educatia pacientilor si, in special, a membrilor familiei cu privire la interactiunea dintre boala de piele, minte si corp, precum si informatiile despre tratamentul medicamentos si nonfarmacologic constituie cheia monitorizarii si diagnosticarii cu succes a acestora. Este importanta, totodata, si instruirea cu privire la efectele medicamentelor, chiar si a celor secundare, doza si sinergismul acestora cu alte medicamente. Pentru modalitatile terapeutice nonfarmacologice, educatia pe intelesul pacientului constituie, de asemenea, cheia succesului. Astfel, complianta este optima atunci cand pacientul si familia sunt bine instruiti cand sunt monitorizati fie prin telefon, fie prin controale periodice, toate acestea motivand pacientul si familia acestuia. (4)

Plecand de la propunerile lui Fried in privinta abordarii terapeutice a bolilor dermatologice cu determinism psihosomatic, conduita este organizata pe trei niveluri: lezional, in care se utilizeaza terapia dermatologica conventionala; emotional, bazat pe cooperarea medic--pacient, ceea ce ofera suportul emotional--empatic si cognitiv, ce are ca obiectiv inlaturarea convingerilor eronate despre cauze si contagiozitate. (5)

Tratamentul optim este cel etiologic, prin indepartarea pe cat posibil a factorului/conditiei care il declanseaza. In absenta depistarii cauzei, se impune un tratament simptomatic general si local, care vizeaza administrarea de antihistaminice (in special anti-H1), desensibilizante nespecifice, aplicatii locale de dermatocorticoizi.

Medicatia psihotropa utilizata cuprinde antidepresivele, antipsihoticele si anxioliticele, acestea actionand la nivel cutanat prin inhibarea proteinkinazei C, care catalizeaza fosforilarea substraturilor proteice cutanate. Nu demult, mitrazepina, un antidepresiv dublu serotoninergic si noradrenergic, a fost promovata pentru pruritul greu de rezolvat, inclusiv mancarimea din limfomul cutanat cu celule B. (2)

Ameliorarea pruritului a fost indusa si prin PUVA-terapie (photochemoterapie cu UV, tip A), metoda a carei mecanisme de actiune constau in inhibarea ADN-ului, prin formarea unor legaturi stabile intre bazele pirimidinice si prin reducerea numarului de celule epidermale, de tip Langerhans, determinand scaderea celulelor inflamatorii.

Indiferent de natura pruritului, pentru o monitorizare eficienta si o buna abordare terapeutica, sunt necesare colaborari interdisciplinare intre dermatologi, psihiatri, internisti si psihologi, care sa reactioneze in sprijinul bolnavului si al familiei acestuia.

Laura Gheuca-Solovastru--M. D., Ph. D., Conferentiar universitar, Universitatea de Medicina si Farmacie "Gr. T. Popa" Iasi, Disciplina Dermatologie; Medic Primar Dermatovenerologie, Clinica Dermatovenerologie, Spitalul Clinic Judetean de Urgente "Sf. Spiridon" Iasi, Romania

Adriana Patrascu--M. D., Medic rezident dermatovenerologie, Clinica Dermatovenerologie, Spitalul Clinic Judetean de Urgente "Sf. Spiridon" Iasi, Romania

Alina Stancanu--M. D., Medic Specialist Dermatovenerologie, Clinica Dermatovenerologie, Spitalul Clinic Judetean de Urgente "Sf. Spiridon" Iasi, Romania

Laura Statescu--M. D., Ph. D., Asistent Universitar, Universitatea de Medicina si Farmacie "Gr. T. Popa" Iasi, Medic Specialist Dermatovenerologie, Clinica Dermatovenerologie, Spitalul Clinic Judetean de Urgente "Sf. Spiridon" Iasi, Romania

Romeo Petru Dobrin--M. D., Ph. D., Sef Lucrari, Universitar, Universitatea de Medicina si Farmacie "Gr. T. Popa" Iasi, Disciplina Psihiatrie, Medic Primar Psihiatru, Spitalul Clinic de Psihiatrie "Socola", Iasi, Romania

Dan Vata--M. D., Ph. D., Asistent Universitar, Universitatea de Medicina si Farmacie "Gr. T. Popa" Iasi, Disciplina Dermatologie; Medic Specialist Dermatovenerologie, Clinica Dermatovenerologie, Spitalul Clinic Judetean de Urgente "Sf. Spiridon" Iasi, Romania

MULTUMIRI SI DEVOALARI

Autorii declara ca nu au potentiale conflicte de interese de declarat in legatura cu acest articol.

BIBLIOGRAFIE

1. Bucur, Gheorghe, Opris, Dana Angela, Boli dermatovenerice, enciclopedie, editia a Il-a, Editura Medicala Nationala, Bucuresti, 2002, p. 604

2. Burns, Tony, Breathnach, Stephen, Cox, Neil, Griffiths, Christopher. Rook's Textbook of Dermatology, Eighth edition, 2010, Vol. I, 21:12

3. Butler, David F., M. D.; Chief Editor: Elston, Dirk M., M. D., Pruritus and Systemic Disease, http://emedicine.medscape.com/ article/ 1098029-followup

4. Dumitru, Justin, Diaconu, C., Coman, Oana Andreia, Benea, Vasile. Tratat de terapeutica dermato-venerologica, Editura Viata Medicala Romaneasca, Bucuresti, 2002, 1.2:108-118

5. Forsea, Dan, Popescu, Raluca, Popescu, Catalin Mihai. Compendiu de dermatologie si venerologie, Editura Tehnica, Bucuresti, 1996, 10: 54

6. Hong Liang, Tey, MD, Joanna Wallengren, MD and Gil Yosipovitch, MD, Psychosomatic factors in pruritus, Clinics in Dermatology, Volume 31, Issue 1:31-40, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3690364

7. Hunter, J. A. A., Salvin, John, Dahl, Mark, Clinical Dermathology, Third Edition, p. 299

8. Levenson, James L., M. D., Textbook of Psychosomatic Medicine, First Edition, American Psychiatric Publishing, Inc, Washington, D. C., p. 634

9. McMahon, Stephen, Koltzenburg, Martin, Tracey, Irene, Turk, Dennis C., Wall & Melzack's, Textbook of Pain: Expert Consult--Online, sixth edition, 21.17

10. Misery, Laurent, Stader, Sonja. Pruritus, London, 2010, 35:223-227

11. Misery, Laurent, Alexandre, Sophie, Dutray, Sabine et al. Functional Itch Disorder or Psychogenic Pruritus: Suggested Diagnosis Criteria From the Franch Psychodermatology Group, Acta Derm Venerol 2007; 87:341-344, www.medicaljournals.se/acta/content/

12. Paus, R., Schmelz, M., Biro, T., Steinhoff, M. Frontiers in pruritus research: scratching the brain for more efective itch therapy. J.Clin Invest, 2006; 116: 1174-1185, http://books.google.ro

13. Philip, A., Shenefelt, D., MD, MS, Management of Psychodermatologic Disorders, Dermatology Nursing, October 2010, http://www.medscape.com/viewarticle/730033_2

14. Raap, Ulrike, Stander, Sonja, Metz, Martin, Pathophysiology of Itch and New Treatments, Current Opinion in Allergy and Clinical Immunology, October 2011, http://www.medscape.com/viewarticle/749608

15. Stoudemire, Alan, MD & Barry S. Fogel, MD, Medical Psychiatric practice, volume I, Americam Psychiatric Press, INC, Washington, D.C., 2005, p. 293

16. http://en.wikipedia.org/ wiki/Interleukin_2#Pruritus_.28itch.29;

Corespondenta:

DAN VATA

Clinica Dermatovenerologie, Spitalul "Sf. Spiridon", Str. Ciurchi nr.111, Iasi, Romania

Tel.: +40 741 084 264

E-mail: danvata@yahoo.com

Primit: August, 27, 2013/ Acceptat: Noiembrie, 12, 2013

Table 1: Diagnosis criteria of functional disorder-Acta
Derm. Venerol (3).

Mandatory diagnostic criteria    Optional criteria

* localized or generalized       * chronological relationship
  self-contained pruritus          regarding the occurrence
  (without primary skin            of itching, with one or
  lesion)                          more events with
* chronic pruritus (more           psychological repercussions
  than 6 weeks)                  * changes associated with
* without a somatic cause          stress
                                 * nycthemeral variations
                                 * predominance while at rest
                                   or in activity
                                 * psychological distress
                                 * pruritus that could be
                                   improved by psychotherapy
                                 * pruritus that could be
                                   improved by psychotropic
                                   drugs

Tabel 1: Criterii de diagnostic al tulburarii
functionale--Acta Derm. Venerol (3)

Criterii de diagnostic     Criterii optionale
obligatorii

* prurit localizat sau     * relatie cronologica de
  generalizat de sine        aparitie a pruritului
  statator (fara leziune     cu unul sau mai multe
  cutanata primara)          evenimente cu

* prurit cronic (mai         repercusiuni psihologice
  mult de sase             * modificari asociate cu
  saptamani)                 stresul variatii

* fara o cauza somatica      nictemerale

                           * predominanta in repaus
                             sau in activitate

                           * tulburari psihologice
                             asociate

                           * prurit ce ar putea fi
                             ameliorat prin
                             psihoterapie

                           * prurit ce poate fi
                             ameliorat prin medicatie
                             psihotropa

Source Citation

Source Citation   (MLA 8th Edition)
Gheuca-Solovastru, Laura, et al. "Pschogenic pruritus/Pruritul psihogen." Bulletin of Integrative Psychiatry, vol. 19, no. 4, 2013, p. 112+. Gale Academic Onefile, https%3A%2F%2Flink.gale.com%2Fapps%2Fdoc%2FA464450258%2FAONE%3Fu%3Dgooglescholar%26sid%3DAONE%26xid%3D9e06249f. Accessed 15 Oct. 2019.

Gale Document Number: GALE|A464450258