Pruritus is usually an unpleasant sensation that elicits a desire to scratch, subjectively quantified by intensity, severity, location, and intractability. It may be proposed that itch is akin to pain because both sensations are thought to be transmitted from skin to central nervous system (CNS) through nociceptive small-caliber C nerve fibers.[
For the purpose of this discussion, a focus will be placed on pruritus in the absence of a primary dermatosis, as is often encountered in patients receiving cancer treatment. However, there may still be significant secondary skin change noted in the form of lichen simplex chronicus, prurigo nodules, linear excoriations, linear petechiae, or superficial erosions in places the patient can reach to scratch (either with fingernails, back scratchers, or makeshift tools).
It is estimated that pruritus is a manifestation of an underlying systemic disease in approximately 10% to 25% of affected individuals.[
Despite the wide array of diseases that may present with pruritus, a systematic evaluation of the differential using a good history, review of systems, and appropriate blood work will lead to a rational and finite group of etiologies. Then correction of the underlying cause (if possible) and treatment of the pruritus with currently available therapies may ensue.
In this summary, unless otherwise stated, evidence and practice issues as they relate to adults are discussed. The evidence and application to practice related to children may differ significantly from information related to adults. When specific information about the care of children is available, it is summarized under its own heading.
When a primary dermatitis is present, the differential may be narrowed by the history and physical findings, such as:
Biopsy of skin dermatitis may be extraordinarily helpful in this scenario if the etiology is not readily evident from history and physical exam alone. In contrast, Table 1 provides a list of differential diagnoses for when there is little or no primary dermatitis identifiable. Where available, the incidence of pruritus in that condition is given.
|Disease State||Prevalence of Pruritus (%)|
|HMG-CoA = 3-hydroxy-3-methyl-glutaryl–coenzyme A; IgE = immunoglobulin E.|
|– Hodgkin disease||30[
|– Non-Hodgkin lymphoma||15[
|– Carcinoid syndrome|
|Iron deficiency anemia|
|Polycythemia rubra vera||≤50[
|Parasitic helminthic infection|
|Chronic renal insufficiency||57[
|– Primary biliary cirrhosis||69[
|– Viral hepatitis infection||15[
|– Cholestatic disease|
|– Autoimmune hepatitis|
|– Hashimoto thyroiditis|
|– Opioids (codeine, morphine, butorphanol)|
|– Hydroxyethyl starch|
|– Antimalarials (chloroquine, hydroxychloroquine, quinacrine)|
|– Beta blockers|
|– Hormones (estrogens, testosterone, progestins, anabolic steroids)|
|– HMG-CoA reductase inhibitors|
|Psychogenic (somatization, anxiety, depression, neurosis)|
As evident from the differential, a solid history and physical are essential for sorting through the possibilities. To corroborate the clinical impression, a limited number of laboratory and radiological examinations also may be used to rule in or rule out many of the possibilities. (Refer to the Assessment section of this summary for more information.)
Hypothesized mechanisms of pruritus have been inferred from studies of pain because pain and itching share common molecular and neurophysiological mechanisms.[
It is believed that nonanatomic factors (such as psychological stress, tolerance, and presence and intensity of other sensations and/or distractions) determine itch sensitivity in different regions of the body.
The itch impulse is transmitted along the same neural pathway as pain impulses, i.e., traveling from peripheral nerves to the dorsal horn of the spinal cord, across the cord via the anterior commissure, and ascending along the spinothalamic tract to the laminar nuclei of the contralateral thalamus. Thalamocortical tracts of tertiary neurons are believed to relay the impulse through the integrating reticular activating system of the thalamus to several areas of the cerebral cortex. Factors that are believed to enhance the sensation of itch include:[
The motor response of scratching follows the perception of itch. Scratching is modulated at the corticothalamic center and is a spinal reflex. Itching may be relieved for 15 to 25 minutes after scratching. The mechanism through which the itch is relieved by scratching is unknown. It is hypothesized that scratching generates sensory impulses that break circuits in the relay areas of the spinal cord. Scratching may actually enhance the sensation of itching, creating a characteristic itch-scratch-itch cycle. Other physical stimuli such as vibration, heat, cold, and ultraviolet radiation diminish itching and increase the release of proteolytic enzymes, potentially eliciting the itch-scratch-itch cycle.
A pinprick near or in the same dermatome as an itchy point will abolish the itch sensation.[
Hypothesized pathogenesis of pruritus associated with underlying disease states are varied. Biliary, hepatic, renal, and malignant diseases are thought to produce pruritus through circulating toxic substances. Histamine released from circulating basophils and the release of leukopeptidase from white blood cells may trigger pruritus associated with lymphomas and leukemias. Elevated blood levels of kininogen in Hodgkin lymphoma, the release of histamine or bradykinin precursors from solid tumors, and the release of serotonin in carcinoids may all be related to pruritus.[
People receiving cytotoxic chemotherapy, radiation therapy, and/or biologic response modifiers for the treatment of malignancy are likely to experience pruritus. This same population is quite likely to be exposed to many of the other etiologic factors relating to pruritus, ranging from nutrition-related xerosis (dry skin) to radiation desquamation, chemotherapy-induced and biologic agent–induced side effects, antibiotic reactions, and other drug sensitivities. Because many of these therapies lead to decreased cell turnover, skin can become thin, atrophic, and dehydrated. Long-term xerosis may also occur with poor recovery of sweat, sebaceous, and apocrine gland function after a course of cytotoxic therapy.
Pruritus is a symptom, not a diagnosis or disease. Generalized pruritus should be investigated because of its strong medical significance, as outlined above (refer to the Etiology/Pathophysiology section of this summary for more information), particularly if it is interfering with daily activities or sleep, and/or is intractable. Assessment of pruritus must incorporate an accurate and thorough history and physical examination.[
A history includes the following data:
A physical examination will provide data from an assessment of the following:
First-line studies should include the following:
Second-line laboratory studies guided by a review of systems and a physical exam may include the following:
Note: Some citations in the text of this section are followed by a level of evidence. The PDQ Editorial Boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)
If an underlying cause of pruritus is identified, treatment of the primary disease or correction of the underlying abnormality is primary therapy, when feasible. For example, iron supplementation in the setting of iron-deficiency anemia or thyroid supplementation for hypothyroidism should be initiated first. However, gentle skin techniques as outlined below are indicated, even if they are not expected to completely alleviate the symptoms—they should be considered helpful adjuvant therapies.
Interventions for pruritus can be categorized into four distinct groups:
Prevention and Elimination of Provocative Factors
Patients and caregivers must be included in planning and providing care to the extent possible. Education is an important aspect of symptom control. Skin care regimens incorporate protection from the environment, good cleansing practices, and internal and external hydration.[
Adequate nutrition is essential to the maintenance of healthy skin. An optimal diet should include a balance of proteins, carbohydrates, fats, vitamins, minerals, and fluids. Daily fluid intake of at least 3,000 mL is suggested as a guideline but may not be possible for some individuals.[
Aggravating factors should be avoided, including the following:
Alleviating factors should be promoted, as follows:
Heat increases cutaneous blood flow and may enhance itching. Heat also lowers humidity, and skin loses moisture when the relative humidity falls below 40%. A cool, humid environment may reverse these processes. Extensive bathing aggravates dry skin, and hot baths exacerbate fluid loss by causing vasodilation. The vasodilation results in increased blood flow, which enhances itching. Tepid baths have an antipruritic effect, possibly resulting from capillary vasoconstriction.
The goal of skin cleansing is to remove dirt and prevent odor, but actual hygienic practices are influenced by skin type, lifestyle, and culture. Bathing should be limited to 30 minutes every day or every 2 days.
Many soaps are salts of fatty acids with an alkali base, leading to excessive defatting of the skin lipids and altered skin pH, thus irritating the skin. Older adults or individuals with dry skin should limit the use of soaps to areas with apocrine glands. Plain water should suffice for cleaning other skin surfaces. Mild soaps have less soap or detergent content. Soap is a degreaser and can also irritate skin. Superfatted soaps deposit a film of oil on the skin surface, but there is no proof that they are less drying than other soaps, and they may be more expensive.
Residue left by detergents after bathing or used in laundering clothes and linens, as well as fabric softeners and antistatic products, may aggravate pruritus. Clothing detergent residue can be neutralized by the addition of vinegar (1 teaspoon per quart of water) to rinse water. Mild laundry soaps marketed for infant items also may offer a solution.
Loose-fitting, lightweight cotton clothes and cotton bed sheets are suggested. The elimination of heavy bedcovers may alleviate itching by decreasing body heat. Wool and some synthetic fabrics may be irritating. Distraction, music therapy, relaxation, and imagery may be useful to relieve symptoms.[
Some topical agents—including cornstarch, talcum powder, perfumed powders, and bubble baths—can irritate the skin and cause pruritus. Cornstarch has been an acceptable intervention for pruritus associated with dry desquamation related to radiation therapy; however, it should not be applied to moist skin surfaces, areas with hair, sebaceous glands, skin folds (intertriginous zones), or areas close to mucosal surfaces, such as the vagina and rectum.[
Agents with metal ions (i.e., talcum and aluminum used in antiperspirants) enhance skin reactions during external-beam radiation therapy and should be avoided throughout the course of radiation therapy. Talcum-based agents are otherwise preferred over cornstarch-based modalities when needed, particularly for intertriginous zones. Other common ingredients in over-the-counter lotions and creams that may enhance skin reactions include alcohol, topical antibiotics, and topical anesthetics.
If pruritus is thought to be primarily related to dry skin, interventions to improve skin hydration can be employed. The main source of hydration for skin is moisture from the vasculature of underlying tissues. Water, not lipid, regulates the pliability of the epidermis, providing the rationale for using emollients.[
Knowledge about the ingredients in skin care products is essential because many ingredients may enhance skin reactions. The three main ingredients of emollients are as follows:
Other ingredients added to these products—such as thickeners, opacifiers, preservatives, fragrances, and colorings—may cause allergic skin reactions.
Product selection and recommendations must be made in consideration of each patient's unique needs and should incorporate variables such as the following:[
Emollient creams or lotions should be applied at least two or three times daily and after bathing. Gels with a local anesthetic (0.5%–5% lidocaine) can be used on some small areas (with the caveat that gels are composed of mostly alcohol-based vehicles), as often as every 2 hours if necessary.[
Over-the-counter products containing menthol, camphor, pramoxine, or capsaicin can be used for certain areas of worst pruritus. These substances soothe, cool, or inhibit itch sensations, thereby raising the threshold for itch perception. Capsaicin-based therapies are more likely to be beneficial in pruritus of neuropathic origin.[
If significant skin breakdown from scratching has occurred or there is evidence of impetiginization, the use of dilute bleach baths, as is done for patients with atopic dermatitis, may be helpful. A half-cup of plain unscented sodium hypochlorite (bleach) is added to half a tub of tap water for soaking at the beginning of the bath period. If sponge bathing is required, this is equivalent to approximately 5 mL of bleach to 1 gal of water.
Topical steroids can reduce itching, but they reduce blood flow to the skin, resulting in thinning of the skin and increased susceptibility to injury.[
For more-severe xerosis or keratoderma, humectants may be indicated. These not only provide an occlusive or semi-occlusive barrier for water, but also chemically exfoliate an excessively cornified layer while drawing dermal fluid into the epidermal compartment. Choices include: [
Humectants can significantly improve skin pliability and reduce fissuring, but care must be taken that they do not get into fissures because they can cause stinging sensations on open erosions.
Systemic medications useful in the management of pruritus include those directed toward the underlying disease or control of symptoms. Antibiotics can reduce symptoms associated with infection. Oral antihistamines may provide symptomatic relief in histamine-related itching; however, they are not considered useful in pruritus of neuropathic origin. It is believed that the sedative effect of antihistamines adds to their antipruritic efficacy; therefore, a higher dose of antihistamine at bedtime may produce desirable potentiation of the antipruritic effect by also providing this sedative effect. If one antihistamine is ineffective, one from another class may provide relief (refer to Table 2).
Second-generation antihistamines have several advantages over first-generation antihistamines.[
|SR = sustained release.|
| a Table abstracted from Lexicomp Online.[
|First generation||Diphenhydramine||25–100 mg q6h||[
|Hydroxyzine||25–50 mg q6–8h||Abrupt withdrawal may cause confusion.||[
|Cyproheptadine||4 mg q6–8h||[
|Chlorpheniramine||4 mg q4–6h||[
|Second generation||Cetirizine||5–10 mg daily||Conflicting results when 20–40 mg/day studied.||[
|Levocetirizine||2.5–5 mg daily||Safe to increase dose up to 20 mg daily; may provide better symptom control.||[
|Loratadine||10 mg daily||[
|Desloratadine||5 mg daily||Safe to increase dose up to 20 mg daily; may provide better symptom control.||[
|Fexofenadine||60 mg q12h or 180 mg daily (SR tablet)||[
Several alternative medications can be used to alleviate pruritus (refer to Table 3). Antidepressants can have strong antihistamine and antipruritic effects.[
Aspirin seems to have reduced pruritus in some individuals with polycythemia vera, while increasing pruritus in others. Thrombocytopenic cancer patients should be cautioned against using aspirin. Cimetidine alone or in combination with aspirin has been used with some effectiveness for pruritus associated with Hodgkin lymphoma and polycythemia vera.[
Novel agents that may be tried in recalcitrant cases of pruritus include gabapentin, pregabalin, and botulinum toxin injection, particularly for neurogenic itch such as post-herpetic neuralgia.[
|ESRD = end-stage renal disease; GABA = gamma-aminobutyric acid; IV = intravenously; tid = 3 times a day.|
| a Table abstracted from Lexicomp Online.[
|Tricyclic antidepressant||Amitriptyline||25–150 mg daily||Start as 10 mg tid or 25 mg at bedtime.||[
|Doxepin||10–25 mg q8h||[
|Selective serotonin reuptake inhibitor||Fluvoxamine||50–100 mg daily||[
|Mirtazapine||7.5–15 mg at bedtime||No value to >15 mg.||[
|Paroxetine||20 mg daily||[
|Sertraline||75–100 mg daily||[
|GABA analog||Gabapentin||100–300 mg daily, titrated to effect||Dose must be adjusted for renal dysfunction.||[
|Pregabalin||75 mg daily||Dose must be adjusted for renal dysfunction.||[
|Sequestrant agent||Ursodiol (ursodeoxycholic acid)||10–15 mg/kg of body weight per day||For pruritus of cholestasis.||[
|Cholestyramine||4–16 g daily||For pruritus of cholestasis.||[
|Opioid antagonist||Naloxone||0.2 µg/kg of body weight per min IV||Efficacy in cholestatic pruritus; conflicting results in ESRD itch. Can cause pain by antagonizing mu-receptor.||[
|Naltrexone||25–100 mg daily||Efficacy in cholestatic pruritus, atopic eczema; conflicting results in ESRD itch. Can cause pain by antagonizing mu-receptor.||[
|Butorphanol||1–4 mg q4–6h intranasally||[
|Nalbuphine||2.5–5 mg IV||For opioid-induced pruritus.||[
|Miscellaneous agent||Aprepitant||80 mg daily||[
|Aspirin||500 mg q8–24h||Only used for polycythemia vera. Positive and negative data.||[
|Botulinum toxin||16–25 units injected into the dermatome||[
|Capsaicin 0.025%||Apply 5 times daily × 1 week, then 3 times daily||For neurologic pruritus.||[
|Cimetidine||200 mg q6h||Only used for polycythemia vera.||[
|Cyclosporine||3–4.5 mg/kg of body weight per day||Requires close monitoring for renal toxicity.||[
|Pimecrolimus 1% cream||Apply twice daily||[
Sequestrant agents may be effective in relieving pruritus associated with renal or hepatic disease through binding and removing pruritogenic substances in the gut and reducing bile salt concentration. Choices include ursodeoxycholic acid and cholestyramine; however, cholestyramine is not always effective and produces gastric side effects.[
Alternatives to scratching for the relief of pruritus can help the patient interrupt the itch-scratch-itch cycle. Substituting the application of emollients for scratching may help reduce skin breakdown. The application of a cool washcloth or ice over the site may be useful. Firm pressure at the site of itching, at a site contralateral to the site of itching, and at acupressure points may break the neural pathway. Rubbing, pressure, and vibration can be used to relieve itching.[
There are anecdotal reports of the use of transcutaneous electronic nerve stimulators (TENS) and acupuncture in the management of pruritus.[
The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
Editorial changes were made to this summary.
This summary is written and maintained by the PDQ Supportive and Palliative Care Editorial Board, which is editorially independent of NCI. The summary reflects an independent review of the literature and does not represent a policy statement of NCI or NIH. More information about summary policies and the role of the PDQ Editorial Boards in maintaining the PDQ summaries can be found on the About This PDQ Summary and PDQ® - NCI's Comprehensive Cancer Database pages.
Purpose of This Summary
This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the pathophysiology and treatment of pruritus. It is intended as a resource to inform and assist clinicians in the care of their patients. It does not provide formal guidelines or recommendations for making health care decisions.
Reviewers and Updates
This summary is reviewed regularly and updated as necessary by the PDQ Supportive and Palliative Care Editorial Board, which is editorially independent of the National Cancer Institute (NCI). The summary reflects an independent review of the literature and does not represent a policy statement of NCI or the National Institutes of Health (NIH).
Board members review recently published articles each month to determine whether an article should:
Changes to the summaries are made through a consensus process in which Board members evaluate the strength of the evidence in the published articles and determine how the article should be included in the summary.
The lead reviewers for Pruritus are:
Any comments or questions about the summary content should be submitted to Cancer.gov through the NCI website's Email Us. Do not contact the individual Board Members with questions or comments about the summaries. Board members will not respond to individual inquiries.
Levels of Evidence
Some of the reference citations in this summary are accompanied by a level-of-evidence designation. These designations are intended to help readers assess the strength of the evidence supporting the use of specific interventions or approaches. The PDQ Supportive and Palliative Care Editorial Board uses a formal evidence ranking system in developing its level-of-evidence designations.
Permission to Use This Summary
PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as "NCI's PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary]."
The preferred citation for this PDQ summary is:
PDQ® Supportive and Palliative Care Editorial Board. PDQ Pruritus. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/about-cancer/treatment/side-effects/skin-nail-changes/pruritus-hp-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389231]
Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.
The information in these summaries should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.
More information about contacting us or receiving help with the Cancer.gov website can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the website's Email Us.
Last Revised: 2021-06-22
This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the
Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Individual and family medical and dental insurance plans are insured by Cigna Health and Life Insurance Company (CHLIC), Cigna HealthCare of Arizona, Inc., Cigna HealthCare of Illinois, Inc., and Cigna HealthCare of North Carolina, Inc. Group health insurance and health benefit plans are insured or administered by CHLIC, Connecticut General Life Insurance Company (CGLIC), or their affiliates (see
All insurance policies and group benefit plans contain exclusions and limitations. For availability, costs and complete details of coverage, contact a licensed agent or Cigna sales representative. This website is not intended for residents of New Mexico.