Individual differences |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |
Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)
Squirrel Scratching the Armpit with its Hindlimb.jpg|
Itch (Latin: pruritus) is a skin disorder with an unpleasant sensation that evokes the desire or reflex to scratch. Psychogenic pruritus (PP) is a diagnosis that can be made when there does not appear to be a physical cause for the condition.
Itch has many similarities to pain and both are unpleasant sensory experiences but their behavioral response patterns are different. Pain creates a reflex withdrawal while 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 peripheral nerve bundle and spinothalamic tract.
Historically, the sensations of itch and pain have not been considered to be independent of each other until recently, where it was found that itch has several features in common with pain, but exhibits notable differences. The physiological mechanisms of itch are currently poorly understood and this is mainly due to the lack of animal models of itch. Pruritic stimuli mostly create the same reactions as noxious stimuli in experimental animals, but humans are capable of discerning the distinct features of itch and pain. Therefore human studies have provided most of the information regarding the processing of pruritic stimuli.
- 1 Mechanism
- 2 Interactions between itch and pain
- 3 Causes
- 4 Treatment
- 5 Common antipruritics
- 6 Sensations associated with scratching
- 7 Footnotes
- 8 See also
- 9 References
- 10 Further reading
- 11 Dissertations
- 12 External links
Mechanism[edit | edit source]
Dermal/pruritoceptive[edit | edit source]
Itch originating in the skin is considered pruritoceptive and can be induced by a variety of stimuli, including mechanical, chemical, thermal, and electrical stimulation. The primary afferent neurons responsible for histamine induced itch are unmyelinated C-fibers. In human C-fiber nociceptors, two major classes exist: mechano-responsive nociceptors and mechano-insensitive nociceptors. Mechano-responsive nociceptors have been shown in studies to respond to mostly pain and mechano-insensitive receptors respond mostly to itch induced by histamine. However it does not explain mechanically induced itch or when itch is produced without a flare reaction which involves no histamine. Therefore it is possible that pruritoceptive nerve fibers have different classes of fibers, which is unclear in current research.
Studies have been done to show that itch receptors are only found on the top two skin layers, the epidermis and the epidermal/dermal transition layers.[How to reference and link to summary or text] Shelley and Arthur had verified the depth by injecting individual itch powder spicules (Mucuna pruriens) and found that maximal sensitivity was found at the basal cell layer or the innermost layer of the epidermis. Surgical removal of those skin layers removed the ability for a patient to perceive itch.[How to reference and link to summary or text] Itch is never felt in muscle, joints, or inner organs, which show that deep tissue does not contain itch signaling apparatuses.
Sensitivity to pruritic stimuli is not even across the skin and has a random spot distribution with similar density to that of pain. The same substances that elicit itch upon intracutaneous injection (injection within the skin) elicit only pain when injected subcutaneously (beneath the skin). Itch is readily abolished in skin areas treated with nociceptor excitotoxin capsaicin but remains unchanged in skin areas which were rendered touch-insensitive by pretreatment with saponins, an anti-inflammatory agent. Although experimentally induced itch can still be perceived under a complete A-fiber conduction block, it is significantly diminished. Overall, itch sensation is mediated by A-delta and C nociceptors located in the uppermost layer of the skin.
Neuropathic[edit | edit source]
Neuropathic itch can originate at any point along the afferent pathway as a result of damage of the nervous system. They could include diseases or disorders in the central nervous system or peripheral nervous system. Examples of neuropathic itch in origin are nostalgia paresthetica, brachioradial pruritis, brain tumors, multiple sclerosis, peripheral neuropathy, and nerve irritation.
Neurogenic[edit | edit source]
Psychogenic[edit | edit source]
Interactions between itch and pain[edit | edit source]
Pain inhibits itch[edit | edit source]
The sensation of itch can be reduced by many painful sensations. Many studies done in the last decade have shown that itch can be inhibited by many other forms of painful stimuli, such as noxious heat, physical rubbing/scratching, noxious chemicals, and electric shock.[How to reference and link to summary or text] Any stimulus that causes pain will inhibit itching.[How to reference and link to summary or text]
The inhibition of itch by painful stimuli, including heat, physical stimulus, and chemical stimulus, has been shown experimentally. In an article written by Louise Ward and others, they studied the effects of noxious and non-noxious counterstimuli, such as heat, physical vibration, or chemical stimulation on skin, in healthy adults after they had experimentally induced itch (transdermal iontophoresis of histamine) and pain (with topical mustard oil) in their skin. They found that when they induced non-noxious counterstimuli, the reduction of pain and itch was reduced only for up to 20 seconds. However when they induced noxious counterstimuli, there was a significant inhibition of itch for an extended period of time but no inhibition of pain. In addition, it was found that brief noxious stimuli created an anti-itch state for more than 30 minutes. These findings show that itch is not a subliminal form of pain and that noxious counterstimulus is likely to act through a central instead of a peripheral mechanism.
Painful electrical stimulation reduced histamine-induced itch for several hours at a distance up to 10 cm from the stimulated site, which suggests a central mode of action.[How to reference and link to summary or text] A new method had been recently found, by Hans-Jorgen Nilsson and others,[vague]
that is able to relieve itch without damaging the skin called cutaneous field stimulation (CFS). CFS consists of a flexible rubber plate with 16 needle-like electrodes placed regularly at 2-centimeter intervals in a 4 by 4 matrix used to electrically stimulate nerve fibers in the surface of the skin. The electrodes were stimulated continuously at 4 Hertz per electrode, pulse duration of 1 millisecond, intensity 0.4-0.8 milliamperes, and for 25 minutes. CFS resulted in a pricking and burning sensation that usually faded away very quickly. The burning sensation was still present during a selective block of impulse conduction of A-fibers in myelinated fibers indicating that nociceptive C-fibers are activated by CFS. In addition, a flare reaction had been noted to develop around the CFS electrodes which indicate activation of axon reflexes in nociceptive C-fibers. Itch, which was induced by transdermal iontophoresis of histamine, was inhibited within the skin area treated with CFS, and it was reduced 10 cm distally to a significant amount. CFS proves to offer a new method of combating itch by using painful electrical stimulation as it creates a long lasting inhibitory effect, does not create any significant skin injuries, and is simple to manage. It is able to activate powerful itch inhibitory mechanisms possibly routed through central mechanisms, which could normally be activated by scratching of the skin.
A study done by Gil Yosipovitch, Katharine Fast, and Jeffrey Bernhard showed that noxious heat and scratching was able to inhibit or decrease itch induced by transdermal iontophoresis of histamine and most interestingly, decrease skin blood flow. Twenty-one healthy volunteers participated in their study. Baseline measurements of skin blood flow were obtained on the flexor part of the forearm and then compared with skin blood flow after various stimuli. Then transdermal iontophoresis of histamine was performed and tested with various stimuli. It is well known that skin blood flow is significantly increased during mechanical scratching, warming, and noxious heat. However it is quite interesting that this study is the first to examine the changes of blood flow by stimuli during iontophoresis of histamine and how itch is perceived in those conditions. Its examination provided an unexpected result that noxious heat and scratching has an inhibitory effect.
A negative correlation was found between pain sensitivity and itch sensitivity. In a study done by Amanda Green and others, they aimed to determine itch-related genetic factors, and establish a more useful animal model for itch. They looked at 11 different inbred mouse strains and compared their scratching behavior in response to two itch inducing agents, histamine and chloroquine. Every strain revealed an inverted-U shape dose response relationship from chloroquine, indicating that moderate dosages produced more scratching than at higher dosages. An explanation is that higher dosage produces more pain and the presence of pain inhibits itch thereby lowering the amount of overall scratching. Another notable result was that histamine induced scratching occurred in female mice on average 23% more than males. Finally, it was found that mice having strains sensitive to pain were resistant to itch and vice versa.
Peripheral sensitization[edit | edit source]
Inflammatory mediators such as bradykinin, serotonin (5-HT) and prostaglandins, released during a painful or pruritic inflammatory condition not only activates pruriceptors but also causes acute sensitization of the nociceptors. In addition, expression of neuro growth factors (NGF) can cause structural changes in of nociceptors such as sprouting. NGF is high in injured or inflamed tissue. Increased NGF is also found in atopic dermatitis, a hereditary and non-contagious skin disease with chronic inflammation. NGF is known to up-regulate neuropeptides, especially substance P. Substance P has been found to have an important role in inducing pain however there is no confirmation that substance P directly causes acute sensitization. Instead substance P may contribute to itch by increasing neuronal sensitization and may the affect release of mast cells, which contain many granules rich in histamine, during long-term interaction.
Central sensitization[edit | edit source]
Noxious input to the spinal cord is known to produce central sensitization, which consists of allodynia, exaggeration of pain, and punctuate hyperalgesia, extreme sensitivity to pain. Two types of mechanical hyperalgesia can occur: 1) touch that is normally painless in the uninjured surroundings of a cut or tear can trigger painful sensations (touch-evoked hyperalgesia), and 2) a slightly painful pin prick stimulation is perceived as more painful around a focused area of inflammation (punctuate hyperalgesia). Touch-evoked hyperalgesia requires continuous firing of primary afferent nociceptors, and punctuate hyperalgesia does not require continuous firing which means it can persist for hours after a trauma and can be stronger than normally experienced. In addition, it was found that patients with neuropathic pain, histamine ionophoresis resulted in a sensation of burning pain rather than itch, which would be induced in normal healthy patients. This shows that there is spinal hypersensitivity to C-fiber input in chronic pain.
Causes[edit | edit source]
Itching can be caused by:
- Head lice if limitted to the neck and scalp.
- Pubic lice if limitted to the genital area.
- Body louse can be seen in substandard living condition.
- Urticaria Urticaria (also called hives) usually causes itching.
- Xerosis (dry skin). This is the most common cause,[How to reference and link to summary or text] frequently seen in winters. Associated with older age, frequent bathing in hot showers or baths, and high temperature and low humidity environments.
- Skin conditions (such as psoriasis, eczema, sunburn, athlete's foot, hidradenitis suppurativa and many others). Most are of an inflammatory nature.
- Insect bites, such as those from mosquitos or chiggers.
- Allergic reactions to contact with specific chemicals, such as Urushiol derived from Poison Ivy or Poison Oak.
- Hodgkin's disease
- Jaundice (bilirubin is a skin irritant at high concentrations)
- Polycythemia, which can cause generalized itching due to increased histamine
- Punctate palmoplantar keratoderma
- Scabies especially when several close contact also itch.
- Thyroid illness
- Shaving, which may irritate the skin
- Diabetes Mellitus
- Dandruff (an unusually large amount of flaking is associated with this sensation)
- Iron deficiency anemia
- Parasitic infections see head lice, body lice, scabies, pubic lice.
- Related to pregnancy:
- Malignancy or internal cancer such as lymphoma.
Treatment[edit | edit source]
- Main article: Antipruritic
A variety of over-the-counter and prescription anti-itch drugs are available. Some plant products have been found to be effective anti-pruritics, others not. Non-chemical remedies include cooling, warming, soft stimulation.
Common antipruritics[edit | edit source]
Topical antipruritics in the form of creams and sprays are often available over-the-counter. Oral anti-itch drugs also exist and are usually prescription drugs. The active ingredients usually belong to the following classes:
- Antihistamines such as diphenhydramine (Benadryl)
- Corticosteroids such as hydrocortisone topical cream, see topical steroid
- Local anesthetics such as benzocaine topical cream (Lanacane)
- Counterirritants, such as mint oil, menthol, or camphor
- Crotamiton (trade name Eurax) is an antipruritic agent available as a cream or lotion often used to treat scabies. Its mechanism of action remains unknown.
Phototherapy is helpful for severe itching, especially if caused by renal failure. The common type of light used is UVB.
Sometimes scratching relieves isolated itches, hence the existence of devices such as the back scratcher. Often, however, scratching can intensify itching and even cause further damage to the skin, dubbed the "itch-scratch-itch cycle".
The mainstay of therapy for dry skin is maintaining adequate skin moisture and topical emollients.
Sensations associated with scratching[edit | edit source]
Pain and itch have very different behavioral response patterns. Pain evokes a withdrawal reflex which leads to retraction and therefore a reaction trying to protect an endangered part of the body. Itch creates a scratching reflex which draws one to the affected skin site. For example, responding to a local itch sensation is an effective way to remove insects on the skin. Scratching has traditionally been regarded as a way to relieve oneself by reducing the annoying itch sensation. However there are hedonic aspects of scratching as one would find noxious scratching highly pleasurable. This can be problematic with chronic itch patients, such as ones with atopic dermatitis, who may scratch affected spots until it no longer produces a pleasant or painful sensation instead of when the itch sensation disappears. It has been hypothesized that motivational aspects of scratching include the frontal brain areas of reward and decision making. These aspects might therefore contribute to the compulsive nature of itch and scratching.
Contagious itch[edit | edit source]
Events of "contagious itch" are very common occurrences. Even a discussion on the topic of itch can give one the desire to scratch. Itch is likely to be more than a localized phenomenon in the place we scratch. Results from a recent study showed that itching and scratching were induced purely by visual stimuli in a public lecture on itching. There is currently little detailed data on central activation for contagious itching but it is hypothesized that a human mirror neuron system exists in which we imitate certain motor actions when we view others performing the same action. A similar phenomenon in which mirror neurons are used to explain the cause is contagious yawning.
Footnotes[edit | edit source]
- Ikoma A, Steinhoff M, Ständer S, Yosipovitch G, Schmelz M (2006). The neurobiology of itch. Nat. Rev. Neurosci. 7 (7): 535–47.
- Greaves MW, Khalifa N (2004). Itch: more than skin deep. Int. Arch. Allergy Immunol. 135 (2): 166–72.
- Twycross R, Greaves MW, Handwerker H, et al (2003). Itch: scratching more than the surface. QJM 96 (1): 7–26.
- Ward L, Wright E, McMahon SB (1996). A comparison of the effects of noxious and innocuous counterstimuli on experimentally induced itch and pain. Pain 64 (1): 129–38.
- Yosipovitch G, Greaves MW, Schmelz M (2003). Itch. Lancet 361 (9358): 690–4.
- Schmelz M, Schmidt R, Bickel A, Handwerker HO, Torebjörk HE (1997). Specific C-receptors for itch in human skin. J. Neurosci. 17 (20): 8003–8.
- Bernhard JD (2005). Itch and pruritus: what are they, and how should itches be classified?. Dermatol Ther 18 (4): 288–91.
- Nilsson HJ, Levinsson A, Schouenborg J (1997). Cutaneous field stimulation (CFS): a new powerful method to combat itch. Pain 71 (1): 49–55.
- Yosipovitch G, Fast K, Bernhard JD (2005). Noxious heat and scratching decrease histamine-induced itch and skin blood flow. J. Invest. Dermatol. 125 (6): 1268–72.
- Green AD, Young KK, Lehto SG, Smith SB, Mogil JS (2006). Influence of genotype, dose and sex on pruritogen-induced scratching behavior in the mouse. Pain 124 (1-2): 50–8.
- Rukwied R, Lischetzki G, McGlone F, Heyer G, Schmelz M (2000). Mast cell mediators other than histamine induce pruritus in atopic dermatitis patients: a dermal microdialysis study. Br. J. Dermatol. 142 (6): 1114–20.
- eMedicine - Hyperparathyroidism : Article by James LaBagnara
- Botero F. Pruritus as a manifestation of systemic disorders. Cutis. 1978; 21:873-880.
- Hercogová J (2005). Topical anti-itch therapy. Dermatologic therapy 18 (4): 341–3.
- Botero F. Pruritus as a manifestation of systemic disorders. Cutis. 1978; 21:873-880.
- Karsak M, Gaffal E, Date R, et al (2007). Attenuation of allergic contact dermatitis through the endocannabinoid system. Science 316 (5830): 1494–7.
See also[edit | edit source]
References[edit | edit source]
- Andrew D, Craig AD (2001). Spinothalamic lamina I neurons selectively sensitive to histamine: a central neural pathway for itch. Nat. Neurosci. 4 (1): 72–7.
- National Cancer Institute (2003) "Pruritus" Retrieved Aug. 22, 2005.
Further reading[edit | edit source]
- Atanassoff, P. G., Brull, S. J., Zhang, J., Greenquist, K., Silverman, D. G., & LaMotte, R. H. (1999). Enhancement of experimental pruritus and mechanically evoked dysesthesiae with local anesthesia: Somatosensory & Motor Research Vol 16(4) 1999, 291-298.
- Barale, F., & et al. (1982). Aspects of cutaneous experience and of scratching in a group of patients with acute psoriasis: Medicina Psicosomatica Vol 27(1) Jan-Mar 1982, 19-28.
- Biondi, M., Arcangeli, T., & Petrucci, R. M. (2000). Paroxetine in a case of psychogenic pruritus and neurotic excoriations: Psychotherapy and Psychosomatics Vol 69(3) May-Jun 2000, 165-166.
- Brull, S. J., Atanassoff, P. G., Silverman, D. G., Zhang, J., & LaMotte, R. H. (1999). Attenuation of experimental pruritus and mechanically evoked dysesthesiae in an area of cutaneous allodynia: Somatosensory & Motor Research Vol 16(4) 1999, 299-303.
- Czubalski, K. (1974). Psychosomatic aspects of pruritus: Psychiatria Polska Vol 8(5) Sep-Oct 1974, 551-556.
- de L. Horne, D. J., Taylor, M., & Varigos, G. (1999). The effects of relaxation with and without imagery in reducing anxiety and itchy skin in patients with eczema: Behavioural and Cognitive Psychotherapy Vol 27(2) Apr 1999, 143-151.
- DeHaven-Hudkins, D. L., Cowan, A., Burgos, L. C., Daubert, J. D., Cassel, J. A., DeHaven, R. N., et al. (2002). Antipruritic and antihyperalgesic actions of loperamide and analogs: Life Sciences Vol 71(23) Oct 2002, 2787-2796.
- Dey, D. D., Landrum, O., & Oaklander, A. L. (2005). Central neuropathic itch from spinal-cord cavernous hemangioma: A human case, a possible animal model, and hypotheses about pathogenesis: Pain Vol 113(1-2) Jan 2005, 233-237.
- Doucet, P. (1988). Pruritus ani: International Journal of Psycho-Analysis Vol 69(3) 1988, 409-417.
- Drzezga, A., Darsow, U., Treede, R.-D., Siebner, H., Frisch, M., Munz, F., et al. (2001). Central activation by histamine-induced itch: Analogies to pain processing: A correlational analysis of O-15 H-sub-2O positron emission tomography studies: Pain Vol 92(1-2) May 2001, 295-305.
- Dunn, J., Murphy, M. B., & Fox, K. M. (2007). Diffuse pruritic lesions in a 37-year-old man after sleeping in an abandoned building: American Journal of Psychiatry Vol 164(8) Aug 2007, 1166-1172.
- Ehlers, A., Stangier, U., Dohn, D., & Gieler, U. (1993). Cognitive factors in itching: Development and validation of a questionnaire: Verhaltenstherapie Vol 3(2) Jun 1993, 112-119.
- Ekblom, A., Lind, G., Meyerson, B. A., Lengstam, I., & et al. (1996). Sympathectomy does not influence experimental itch and cutaneous temperature perception thresholds: Somatosensory & Motor Research Vol 13(2) 1996, 147-152.
- Elberlik, K. (1980). Organ loss, grieving and itching: American Journal of Psychotherapy Vol 34(4) Oct 1980, 523-533.
- Engman, M., Wijma, K., & Wijma, B. (2007). Itch and Burning Pain in Women with Partial Vaginismus with or without Vulvar Vestibulitis: Journal of Sex & Marital Therapy Vol 33(2) 2007, 171-186.
- Frigon, C., & Desparmet, J. (2006). Un traitement a l'ondansetron pour un enfant atteint d'un prurit chronique refractaire: Pain Research & Management Vol 11(4) Win 2006, 245-247.
- Fruensgaard, K. (1984). Neurotic excoriations: A controlled psychiatric examination: Acta Psychiatrica Scandinavica Suppl 69(312) 1984, 3-52.
- Fruhstorfer, H., Hermanns, M., & Latzke, L. (1986). The effects of thermal stimulation on clinical and experimental itch: Pain Vol 24(2) Feb 1986, 259-269.
- Gabriel, G. M., & Crone, C. C. (2001). Nocturnal pruritus in a cardiac pretransplant patient: Psychosomatics: Journal of Consultation Liaison Psychiatry Vol 42(4) Jul-Aug 2001, 344-346.
- Gallelli, L., De Fazio, S., Corace, E., De Sarro, G., Garcia, C. S., & De Fazio, P. (2006). Generalised Urticaria in a Young Woman treated with Clomipramine and after Ingestion of Codfish: Pharmacopsychiatry Vol 39(4) Jul 2006, 154-156.
- Ginsberg, D. L. (2004). Paroxetine effective for severe nondermatological pruritus: Primary Psychiatry Vol 11(7) Jul 2004, 22-23.
- Ginsberg, D. L. (2004). Paroxetine Treatment of Opioid-Resistant, Persistent Dry Cough: Primary Psychiatry Vol 11(10) Oct 2004, 24-29.
- Green, B. G. (1990). Spatial summation of chemical irritation and itch produced by topical application of capsaicin: Perception & Psychophysics Vol 48(1) Jul 1990, 12-18.
- Gupta, M. A., Gupta, A. K., Schork, N. J., & Ellis, C. N. (1994). Depression modulates pruritus perception: A study of pruritus in psoriasis, atopic dermatitis, and chronic idiopathic urticaria: Psychosomatic Medicine Vol 56(1) Jan-Feb 1994, 36-40.
- Habib, S., & Morrissey, S. (1999). Stress management for atopic dermatitis: Behaviour Change Vol 16(4) 1999, 226-236.
- Hama, H., Mine, H., & Matsuyama, Y. (1982). Effects of counterirritation on experimentally produced itching: Japanese Psychological Research Vol 24(4) 1982, 188-194.
- Hama, H., Tanabe, T., & Suzuki, N. (1986). A study of itch intensity in relation to two-point tactual discrimination: Japanese Journal of Psychology Vol 57(3) Aug 1986, 179-182.
- Herde, L., Forster, C., Strupf, M., & Handwerker, H. O. (2007). Itch induced by a novel method leads to limbic deactivations--A functional MRI study: Journal of Neurophysiology Vol 98(4) Oct 2007, 2347-2356.
- Hsieh, J.-C., Hagermark, O., Stahle-Backdahl, M., Ericson, K., & et al. (1994). Urge to scratch represented in the human cerebral cortex during itch: Journal of Neurophysiology Vol 72(6) Dec 1994, 3004-3008.
- Ikoma, A., Steinhoff, M., Stander, S., Yosipovitch, G., & Schmelz, M. (2006). The neurobiology of itch: Nature Reviews Neuroscience Vol 7(7) Jul 2006, 535-547.
- Jaeger, P. (2006). Prurits, chronic irritations of the skin and urticaria. When there is nobody to carry the baby: Revue Francaise de Psychosomatique No 29 2006, 51-66.
- Johanek, L. M., Meyer, R. A., Hartke, T., Hobelmann, J. G., Maine, D. N., LaMotte, R. H., et al. (2007). Psychophysical and physiological evidence for parallel afferent pathways mediating the sensation of itch: Journal of Neuroscience Vol 27(28) Jul 2007, 7490-7497.
- Ko, M. C. H., Lee, H., Song, M. S., Sobczyk-Kojiro, K., Mosberg, H. I., Kishioka, S., et al. (2003). Activation of kappa -Opioid Receptors Inhibits Pruritus Evoked by Subcutaneous or Intrathecal Administration of Morphine in Monkeys: Journal of Pharmacology and Experimental Therapeutics Vol 305(1) Apr 2003, 173-179.
- Kretzmer, G. E., Gelkopf, M., Kretzmer, G., & Melamed, Y. (2008). Idiopathic pruritus in psychiatric inpatients: An explorative study: General Hospital Psychiatry Vol 30(4) Jul 2008, 344-348.
- Laihinen, A. (1987). Psychosomatic aspects in dermatoses: Annals of Clinical Research Vol 19(2) 1987, 147-151.
- Lantz, J. E. (1979). Extreme itching treated by a family systems approach: International Journal of Family Therapy Vol 1(3) Fal 1979, 244-253.
- Laurent, A., Boucharlat, J., Bosson, J.-L., Derry, A., & Imbert, R. (1997). Psychological assessment of patients with idiopathic pruritus ani: Psychotherapy and Psychosomatics Vol 66(3) May-Jun 1997, 163-166.
- Lee, H., Naughton, N. N., Woods, J. H., & Ko, M. C. H. (2003). Characterization of scratching responses in rats following centrally administered morphine or bombesin: Behavioural Pharmacology Vol 14(7) Nov 2003, 501-508.
- Leknes, S. G., Bantick, S., Willis, C. M., Wilkinson, J. D., Wise, R. G., & Tracey, I. (2007). Itch and motivation to scratch: An investigation of the central and peripheral correlates of allergen- and histamine-induced itch in humans: Journal of Neurophysiology Vol 97(1) Jan 2007, 415-422.
- Madden, E. J. (1986). Itch: Journal of Pain and Symptom Management Vol 1(2) Spr 1986, 97-99.
- Mahtani, R., Parekh, N., Mangat, I., & Bhalerao, S. (2005). Alleviating the Itch-Scratch Cycle in Atopic Dermatitis: Psychosomatics: Journal of Consultation Liaison Psychiatry Vol 46(4) Jul-Aug 2005, 373-374.
- Matas, M., & Robinson, C. (1988). Diagnosis and treatment of monosymptomatic hypochondriacal psychosis in chronic renal failure: The Canadian Journal of Psychiatry / La Revue canadienne de psychiatrie Vol 33(8) Nov 1988, 748-750.
- McLeod, R. P. (2005). Lumps, Bumps, and Things That Go Itch in Your Office! : The Journal of School Nursing Vol 21(3) Jun 2005, 184-186.
- Mine, H. (1992). Itch and the heat tolerance scale: Effects of thermographic biofeedback: Japanese Journal of Psychology Vol 62(6) Feb 1992, 335-341.
- Mitchell, C. W. (1995). Effects of subliminally presented auditory suggestions of itching on scratching behavior: Perceptual and Motor Skills Vol 80(1) Feb 1995, 87-96.
- Murray, F. S., & Weaver, M. M. (1975). Effects of ipsilateral and contralateral counterirritation on experimentally produced itch in human beings: Journal of Comparative and Physiological Psychology Vol 89(7) Sep 1975, 819-826.
- Nakano, T., Andoh, T., Lee, J.-B., & Kuraishi, Y. (2008). Different dorsal horn neurons responding to histamine and allergic itch stimuli: Neuroreport: For Rapid Communication of Neuroscience Research Vol 19(7) May 2008, 723-726.
- No authorship, i. (2005). Paroxetine Withdrawal Pruritus: Primary Psychiatry Vol 12(1) Jan 2005, 18-19.
- Oaklander, A. L. (2008). Mechanisms of pain and itch caused by herpes zoster (shingles): The Journal of Pain Vol 9(1, Suppl 1) Jan 2008, S10-S18.
- Oliveira, F. A., Lima-Junior, R. C. P., Cordeiro, W. M., Vieira-Junior, G. M., Chaves, M. H., Almeida, F. R. C., et al. (2004). Pentacyclic triterpenoids, alpha ,beta -amyrins, suppress the scratching behavior in a mouse model of pruritus: Pharmacology, Biochemistry and Behavior Vol 78(4) Aug 2004, 719-725.
- Rietveld, S., Everaerd, W., & Vanbeest, I. (1999). Can biased symptom perception explain false-alarm choking sensations? : Psychological Medicine Vol 29(1) Jan 1999, 121-126.
- Rucklidge, J. J., & Saunders, D. (1999). Hypnosis in a case of long-standing idiopathic itch: Psychosomatic Medicine Vol 61(3) May-Jun 1999, 355-358.
- Rucklidge, J. J., & Saunders, D. (2002). The efficacy of hypnosis in the treatment of pruritus in people with HIV/AIDS: A time-series analysis: International Journal of Clinical and Experimental Hypnosis Vol 50(2) Apr 2002, 149-169.
- Salcuni, S., Caglioni, V., Lis, A., Veller-Fornasa, C., & Bezze, G. (2004). Psychosomatic vulnerability: Psychological correlates of idiopathic pruritus with Rorschach test: Medicina Psicosomatica Vol 49(1-2) 2004, 23-31.
- Sampson, R. N. (1990). Hypnotherapy in a case of pruritus and Guillain-Barre syndrome: American Journal of Clinical Hypnosis Vol 32(3) Jan 1990, 168-173.
- Sandroni, P. (2002). Central neuropathic itch: A new treatment option? : Neurology Vol 59(5) Sep 2002, 778-779.
- Schneider, G., Stander, S., Burgmer, M., Driesch, G., Heuft, G., & Weckesser, M. (2008). Significant differences in central imaging of histamine-induced itch between atopic dermatitis and healthy subjects: European Journal of Pain Vol 12(7) Oct 2008, 834-841.
- Schworer, H., Hartmann, H., & Ramadori, G. (1995). Relief of cholestatic pruritus by a novel class of drugs: 5-hydroxytryptamine type 3 (5-HT-sub-3) receptor antagonists: Effectiveness of ondansetron: Pain Vol 61(1) Apr 1995, 33-37.
- Semionov, V., & Shvartzman, P. (2008). Post herpetic itching--A treatment dilemma: Clinical Journal of Pain Vol 24(4) May 2008, 366-368.
- Shaw, R. J., Dayal, S., Good, J., Bruckner, A. L., & Joshi, S. V. (2007). Psychiatric medications for the treatment of pruritus: Psychosomatic Medicine Vol 69(9) Nov-Dec 2007, 970-978.
- Shertzer, C. L. (1982). Hypnosis in the treatment of urticaria: Dissertation Abstracts International.
- Shukla, S., & Mukherjee, S. (1984). Lichen simplex chronicus during lithium treatment: American Journal of Psychiatry Vol 141(7) Jul 1984, 909-910.
- Simone, D. A., Alreja, M., & LaMotte, R. H. (1991). Psychophysical studies of the itch sensation and itchy skin ("alloknesis") produced by intracutaneous injection of histamine: Somatosensory & Motor Research Vol 8(3) 1991, 271-279.
- Simone, D. A., & Ochoa, J. (1991). Early and late effects of prolonged topical capsaicin on cutaneous sensibility and neurogenic vasodilatation in humans: Pain Vol 47(3) Dec 1991, 285-294.
- Simone, D. A., Zhang, X., Li, J., Zhang, J.-M., Honda, C. N., LaMotte, R. H., et al. (2004). Comparison of Responses of Primate Spinothalamic Tract Neurons to Pruritic and Algogenic Stimuli: Journal of Neurophysiology Vol 91(1) Jan 2004, 213-222.
- Stander, S., & Schmelz, M. (2006). Chronic itch and pain--Similarities and differences: European Journal of Pain Vol 10(5) Jul 2006, 473-478.
- Steinhoff, M., Neisius, U., Ikoma, A., Fartasch, M., Heyer, G., Skov, P. S., et al. (2003). Proteinase-Activated Receptor-2 Mediates Itch: A Novel Pathway for Pruritus in Human Skin: Journal of Neuroscience Vol 23(15) Aug 2003, 6176-6180.
- Sterlin, C., Ban, T. A., Lehmann, H. E., & Jarrold, L. (1972). Doxepin in the treatment of hospitalized and ambulatory psychoneurotic patients: International Journal of Clinical Pharmacology, Therapy & Toxicology Vol 5(4) Feb 1972, 417-419.
- Tantam, D., Kalucy, R., & Brown, D. G. (1982). Sleep, scratching and dreams in eczema: A new approach to alexithymia: Psychotherapy and Psychosomatics Vol 37(1) 1982, 26-35.
- Thomas, D. A., & Hammond, D. L. (1995). Microinjection of morphine into the rat medullary dorsal horn produces a dose-dependent increase in facial scratching: Brain Research Vol 695(2) Oct 1995, 267-270.
- van Os-Medendorp, H., Eland-de Kok, P., van Linge, R., Bruijnzeel-Koomen, C., Grypdonck, M., & Ros, W. (2008). The tailored implementation of the nursing programme 'Coping with itch': Journal of Clinical Nursing Vol 17(11) Jun 2008, 1460-1470.
- van Os-Medendorp, H., Eland-de Kok, P. C. M., Ros, W. J. G., Bruijnzeel-Koomen, C. A. F. M., & Grypdonck, M. (2007). The nursing programme 'Coping with itch': A promising intervention for patients with chronic pruritic skin diseases: Journal of Clinical Nursing Vol 16(7) Jul 2007, 1238-1246.
- Verhoeven, L., Kraaimaat, F., Duller, P., van de Kerkhof, P., & Evers, A. (2006). Cognitive, Behavioral, and Physiological Reactivity to Chronic Itching: Analogies to Chronic Pain: International Journal of Behavioral Medicine Vol 13(3) 2006, 237-243.
- Wasner, G., Schwarz, K., Schattschneider, J., Binder, A., Jensen, T. S., & Baron, R. (2004). Interaction between histamine-induced itch and experimental muscle pain: European Journal of Pain Vol 8(3) Jun 2004, 179-185.
- Woodward, D. F., Nieves, A. L., Spada, C. S., Williams, L. S., & et al. (1995). Characterization of a behavioral model for peripherally evoked itch suggests platelet-activating factor as a potent pruritogen: Journal of Pharmacology and Experimental Therapeutics Vol 272(2) Feb 1995, 758-765.
- Yang, C.-H., Chen, K.-H., Chen, Y.-S., Liu, C.-C., Tseng, C.-C., Cheng, K.-W., et al. (2005). Comparison of the effectiveness of different regimens of epidural analgesia in postcesarean subjects experiencing pruritus: The Pain Clinic Vol 17(2) 2005, 139-143.
- Yao, G. L., Tohyama, M., & Senba, E. (1992). Histamine-caused itch induces Fos-like immunoreactivity in dorsal horn neurons: Effect of morphine pretreatment: Brain Research Vol 599(2) Dec 1992, 333-337.
- Zylicz, Z., Smits, C., Chem, & Krajnik, M. (1998). Paroxetine for pruritus in advanced cancer: Journal of Pain and Symptom Management Vol 16(2) Aug 1998, 121-124.
Dissertations[edit | edit source]
- Dignam, T. F. (1975). A study to measure the effects of psychological stress on normal and pruritanic subjects in an experimental pruritus inducing procedure: Dissertation Abstracts International.
[edit | edit source]
|This page uses Creative Commons Licensed content from Wikipedia (view authors).|