Itching

Definition

Itching is an intense, distracting irritation or tickling sensation that may be felt all over the skin's surface, or confined to just one area. The medical term for itching is pruritus.

Description

Itching instinctively leads most people to scratch the affected area. Different people can tolerate different amounts of itching, and anyone's threshold of tolerance can be changed due to stress, emotions, and other factors. In general, itching is more severe if the skin is warm, and if there are few distractions. This is why people tend to notice itching more at night.

Causes and symptoms

The biology underlying itching is not fully understood. It is believed that itching results from the interactions of several different chemical messengers. Although itching and pain sensations were at one time thought to be sent along the same nerve pathways, researchers reported the discovery in 2003 of itch-specific nerve pathways. Nerve endings that are specifically sensitive to itching have been named pruriceptors.

Research into itching has been helped by the recent invention of a mechanical device called the Matcher, which electrically stimulates the patient's left hand. When the intensity of the stimulation equals the intensity of itching that the patient is experiencing elsewhere in the body, the patient stops the stimulation and the device automatically records the measurement. The Matcher was found to be sensitive to immediate changes in the patient's perception of itching as well as reliable in its measurements.

Stress and emotional upset can make itching worse, no matter what the underlying cause. If emotional problems are the primary reason for the itch, the condition is known as psychogenic itching. Some people become convinced that their itch is caused by a parasite; this conviction is often linked to burning sensations in the tongue, and may be caused by a major psychiatric disorder.

Generalized itching

Itching that occurs all over the body may indicate a medical condition such as diabetes mellitus, liver disease, kidney failure, jaundice, thyroid disorders (and rarely, cancer ). Blood disorders such as leukemia, and lymphatic conditions such as Hodgkin's disease may sometimes cause itching as well.

Some people may develop an itch without a rash when they take certain drugs (such as aspirin, codeine, cocaine ); others may develop an itchy red "drug rash" or hives because of an allergy to a specific drug. Some medications given to cancer patients may also cause itching.

Itching also may be caused when any of the family of hookworm larvae penetrate the skin. This includes swimmer's itch and creeping eruption caused by cat or dog hookworm, and ground itch caused by the "true" hookworm.

Many skin conditions cause an itchy rash. These include:

• Atopic dermatitis
• Chickenpox
• Contact dermatitis
• Dermatitis herpetiformis (occasionally)
• Eczema
• Fungus infections (such as athlete's foot )
• Hives (urticaria)
• Insect bites
• Lice
• Lichen planus
• Neurodermatitis (lichen simplex chronicus )
• Psoriasis (occasionally)
• Scabies.

On the other hand, itching all over the body can be caused by something as simple as bathing too often, which removes the skin's natural oils and may make the skin too dry and scaly.

Localized itching

Specific itchy areas may occur if a person comes in contact with soap, detergents, and wool or other rough-textured, scratchy material. Adults who have hemorrhoids, anal fissure, or persistent diarrhea may notice itching around the anus (called "pruritus ani"). In children, itching in this area is most likely due to worms.

Intense itching in the external genitalia in women ("pruritus vulvae") may be due to candidiasis, hormonal changes, or the use of certain spermicides or vaginal suppositories, ointments, or deodorants.

It is also common for older people to suffer from dry, itchy skin (especially on the back) for no obvious reason. Younger people also may notice dry, itchy skin in cold weather. Itching is also a common complaint during pregnancy.

Diagnosis

Itching is a symptom that is quite obvious to its victim. Someone who itches all over should seek medical care. Because itching can be caused by such a wide variety of triggers, a complete physical exam and medical history will help diagnose the underlying problem. A variety of blood and stool tests may help determine the underlying cause.

Treatment

Antihistamines such as diphenhydramine (Benadryl) can help relieve itching caused by hives, but will not affect itching from other causes. Most antihistamines also make people sleepy, which can help patients sleep who would otherwise be awake from the itch.

Specific treatment of itching depends on the underlying condition that causes it. In general, itchy skin should be treated very gently. While scratching may temporarily ease the itch, in the long run scratching just makes it worse. In addition, scratching can lead to an endless cycle of itch—scratch—more itching.

To avoid the urge to scratch, a person can apply a cooling or soothing lotion or cold compress when the urge to scratch occurs. Soaps are often irritating to the skin, and can make an itch worse; they should be avoided, or used only when necessary.

Creams or ointments containing cortisone may help control the itch from insect bites, contact dermatitis or eczema. Cortisone cream should not be applied to the face unless a doctor prescribes it.

Probably the most common cause of itching is dry skin. There are a number of simple things a person can do to ease the annoying itch:

• Do not wear tight clothes
• Avoid synthetic fabrics
• Do not take long baths
• Wash the area in lukewarm water with a little baking soda
• For generalized itching, take a lukewarm shower
• Try a lukewarm oatmeal (or Aveeno) bath for generalized itching
• Apply bath oil or lotion (without added colors or scents) right after bathing.

Itching may also be treated with whole-body medications. In addition to antihistamines, some of these systemic treatments include:

• tricyclic antidepressants
• sedatives or tranquilizers
• such selective serotonin reputake inhibitors as paroxetine (Paxil) and sertraline (Zoloft)
• binding agents (such as cholestyramine which relieves itching associated with kidney or liver disease).
• aspirin
• cimetidine

People who itch as a result of mental problems or stress should seek help from a mental health expert.

Alternative and complementary therapies

A well-balanced diet that includes carbohydrates, fats, minerals, proteins, vitamins, and liquids will help to maintain skin health. Capsules that contain eicosapentaenoic acid, which is obtained from herring, mackerel, or salmon, may help to reduce itching. Vitamin A plays an important role in skin health. Vitamin E (capsules or ointment) may reduce itching. Patients should check with their treating physician before using supplements.

Homeopathy has been reported to be effective in treating systemic itching associated with hemodialysis.

Baths containing oil with milk or oatmeal are effective at relieving localized itching. Evening primrose oil may soothe itching and may be as effective as corticosteroids. Calendula cream may relieve short-term itching. Other herbal treatments that have been recently reported to relieve itching include sangre de drago, a preparation made with sap from a South American tree; and a mixture of honey, olive oil, and beeswax.

Distraction, music therapy, relaxation techniques, and visualization may be useful in relieving itching. Ultraviolet light therapy may relieve itching associated with conditions of the skin, kidneys, blood, and gallbladder. There are some reports of the use of acupuncture and transcutaneous electrical nerve stimulators (TENS) to relieve itching.

Prognosis

Most cases of itching go away when the underlying cause is treated successfully.

Prevention

There are certain things people can do to avoid itchy skin. Patients who tend toward itchy skin should:

• Avoid a daily bath
• Use only lukewarm water when bathing
• Use only gentle soap
• Pat dry, not rub dry, after bathing, leaving a bit of water on the skin
• Apply a moisture-holding ointment or cream after the bath
• Use a humidifier in the home.

Patients who are allergic to certain substances, medications, and so on can avoid the resulting itch if they avoid contact with the allergen. Avoiding insect bites, bee stings, poison ivy and so on can prevent the resulting itch. Treating sensitive skin carefully, avoiding overdrying of the skin, and protecting against diseases that cause itchy rashes are all good ways to avoid itching.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD, editors. "Pruritus." Section 10, Chapter 109. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

PERIODICALS

Al-Waili, N. S. "Topical Application of Natural Honey, Beeswax and Olive Oil Mixture for Atopic Dermatitis or Psoriasis: Partially Controlled, Single-Blinded Study." Complementary Therapies in Medicine 11 (December 2003): 226-234.

Browning, J., B. Combes, and M. J. Mayo. "Long-Term Efficacy of Sertraline as a Treatment for Cholestatic Pruritus in Patients with Primary Biliary Cirrhosis." American Journal of Gastroenterology 98 (December 2003): 2736-2741.

Cavalcanti, A. M., L. M. Rocha, R. Carillo Jr., et al. "Effects of Homeopathic Treatment on Pruritus of Haemodialysis Patients: A Randomised Placebo-Controlled Double-Blind Trial." Homeopathy 92 (October 2003): 177-181.

Ikoma, A., R. Rukwied, S. Stander, et al. "Neurophysiology of Pruritus: Interaction of Itch and Pain." Archives of Dermatology 139 (November 2003): 1475-1478.

Jones, K. "Review of Sangre de Drago (Croton lechleri )—A South American Tree Sap in the Treatment of Diarrhea, Inflammation, Insect Bites, Viral Infections, and Wounds: Traditional Uses to Clinical Research." Journal of Alternative and Complementary Medicine 9 (December 2003): 877-896.

Ochoa, J. G. "Pruritus, a Rare but Troublesome Adverse Reaction of Topiramate." Seizure 12 (October 2003): 516-518.

Stener-Victorin, E., T. Lundeberg, J. Kowalski, et al. "Perceptual Matching for Assessment of Itch; Reliability and Responsiveness Analyzed by a Rank-Invariant Statistical Method." Journal of Investigative Dermatology 121 (December 2003): 1301-1305.

Zylicz, Z., M. Krajnik, A. A. Sorge, and M. Costantini. "Paroxetine in the Treatment of Severe Non-Dermatological Pruritus: A Randomized, Controlled Trial." Journal of Pain and Symptom Management 26 (December 2003): 1105-1112.

KEY TERMS

Atopic dermatitis— An intensely itchy inflammation often found on the face of people prone to allergies. In infants and early childhood, it is called infantile eczema.

Creeping eruption— Itchy irregular, wandering red lines on the foot made by burrowing larvae of the hookworm family and some roundworms.

Dermatitis herpetiformis— A chronic very itchy skin disease with groups of red lesions that leave spots behind when they heal. It is sometimes associated with cancer of an internal organ.

Eczema— A superficial type of inflammation of the skin that may be very itchy and weeping in the early stages; later, the affected skin becomes crusted, scaly, and thick. There is no known cause.

Hodgkin's disease— A type of cancer characterized by a slowly-enlarging lymph tissue; symptoms include generalized itching.

Lichen planus— A noncancerous, chronic itchy skin disease that causes small, flat purple plaques on wrists, forearm, ankles.

Neurodermatitis— An itchy skin disease (also called lichen simplex chronicus) found in nervous, anxious people.

Pruriceptors— Nerve endings specialized to perceive itching sensations.

Pruritus— The medical term for itching.

Psoriasis— A common, chronic skin disorder that causes red patches anywhere on the body. Occasionally, the lesions may itch.

Scabies— A contagious parasitic skin disease characterized by intense itching.

Swimmer's itch— An allergic skin inflammation caused by a sensitivity to flatworms that die under the skin, causing an itchy rash.

Itching

Definition

Itching is an intense, distracting irritation or tickling sensation that may be felt all over the skin's surface or confined to just one area. The medical term for itching is pruritus.

Description

Itching leads most people instinctively to scratch the affected area. Different people can tolerate different amounts of itching, and anyone's threshold of tolerance can be changed due to stress , emotions, and other factors. In general, itching is more severe if the skin is warm, and if there are few distractions. This is why people tend to notice itching more at night.

Causes & symptoms

As of 2002, the recent discovery of itch-specific neurons (nerve cells) has given doctors a better understanding of the causes of the sensation of itching. Another factor that contributes to itching is the release of endogenous opioids in the body. While these chemicals function primarily to relieve pain , they also appear to enhance the sensation of itching. Although itching is the most noticeable symptom of many skin diseases, however, it doesn't necessarily mean that a person who feels itchy has a disease.

Stress and emotional upset can make itching worse, no matter what the underlying cause. If emotional problems are the primary reason for feeling itchy, the condition is known as psychogenic itching. Some people become convinced that their itch is caused by a parasite or some medical disorder. This conviction is often linked to burning sensations in the tongue, and may be caused by a major psychiatric disorder.

Generalized itching

Itching that occurs all over the body may indicate a medical condition such as diabetes mellitus , liver disease, kidney failure, jaundice , thyroid disorders, and rarely, cancer . Blood disorders such as leukemia , and lymphatic conditions such as Hodgkin's disease may sometimes cause itching as well.

Some people may develop an itch without a rash when they take certain drugs (such as aspirin, codeine, cocaine). Others may develop an itchy, red "drug rash" or hives because of an allergy to a specific drug.

A team of researchers in Texas has discovered that some people infected by Helicobacter pylori, a bacterium that causes gastritis , also develop itching that does not respond to usual treatments. When the bacterium is eradicated from the patient's digestive tract, the itching is relieved.

Itching also may be caused when hookworm larvae penetrate the skin. This type of itching includes swimmer's itch, creeping eruptions caused by cat or dog hookworm, and ground itch caused by the "true" hookworm.

Skin conditions that cause an itchy rash include:

• atopic dermatitis
• chickenpox
• contact dermatitis
• dermatitis herpetiformis (occasionally)
• eczema
• fungal infections (such as athlete's foot )
• hives (urticaria)
• insect bites
• lice
• lichen planus
• neurodermatitis (lichen simplex chronicus)
• psoriasis (occasionally)
• scabies

Itching all over the body can be caused by something as simple as bathing too often, which removes the skin's natural oils and may make the skin too dry and scaly.

Localized itching

Specific itchy areas may occur if a person comes in contact with soaps, detergents, and wool or other rough-textured, scratchy material. Adults who have hemorrhoids , anal fissures, or persistent diarrhea may notice pruritus ani (itching around the anus). In children, itching in this area is most likely due to worms .

Intense itching called pruritus vulvae (itching of the external genitalia in women) may be due to a yeast infection , hormonal changes, contact dermatitis, or the use of certain spermicides, vaginal suppositories, ointments, or deodorants.

It's also common for older people to suffer from dry, itchy skin (especially on the back) for no obvious reason. Moreover, older people are more likely to develop itching as a side effect of prescription medications. Younger people may notice dry, itchy skin in cold weather. Itching is also a common complaint during pregnancy .

Diagnosis

Itching is a symptom that is quite obvious to its victim. Someone who itches all over should seek medical care. Because itching can be caused by such a wide variety of triggers, a complete physical exam and medical history will help diagnose the underlying problem. A variety of blood and stool tests may help determine the underlying cause.

Treatment

In general, itchy skin should be treated very gently. While scratching may temporarily ease the itch, in the long run scratching just makes it worse. In addition, scratching can lead to an endless cycle of more itching and scratching.

To control the urge to scratch, a person can apply a cooling or soothing lotion or cold compress to the area. Itching may be relieved by applying a warm compress of diluted vinegar, preferably such herbal vinegars as plantain , violet, lavender , or rose.

The itching associated with mosquito bites can be reduced by applying meat tenderizer paste, table salt (to wet skin), or toothpaste. Any alkaline preparation (like a paste of baking soda and water ) will help ease the itch.

Probably the most common cause of itching is dry skin. Flaxseed oil and vitamin E taken orally can help to rehydrate dry skin and can reduce itching. There are a number of simple things a person can do to relieve itching.

• Don't wear tight clothes.
• Avoid synthetic fabrics.
• Don't take long baths.
• Wash the area in lukewarm water with a little baking soda.
• Take a lukewarm shower for generalized itching.
• Try a lukewarm oatmeal (or Aveeno) bath for generalized itching.
• Apply bath oil or lotion (without added colors or scents) right after bathing.

Practitioners of Chinese medicine utilize a wide variety of herbs as well as acupuncture and ear acupuncture to treat itching based upon the cause. The medicine Xiao Feng Zhi Yang Chong Ji (Eliminate Wind and Relieve Itching Infusion) can be taken three times daily to relieve itching. For external treatment of itching, the patient may bathe in Zhi Yang Xi Ji (Relieve Itching Washing Preparation) and apply She Chuang Zi Ding (Cnidium Tincture) and Zhi Yang Po Fen (Relieve Itching Powder).

Emotional stress can trigger many different dermatoses, including certain itching rashes . Hypnosis has been helpful in treating atopic dermatitis, itching, psoriasis, hives, and other dermatoses.

In several small studies, transcutaneous electrical nerve stimulation (TENS) has been effective in temporarily relieving chronic itch associated with varying dermatoses. TENS is a treatment in which mild electrical current is passed through electrodes on the skin to stimulate nerves and block pain signals. Portable TENS units are available for home use.

Cutaneous field stimulation (CFS) was found to safely relieve experimentally induced itching for a longer time period than TENS. CFS electrically stimulates nerves in the skin to harmlessly mimic scratching and inhibit the itch sensation.

Herbal itch remedies

The following herbal remedies for itching are used externally:

• aloe vera
• bracken juice
• bird-of-paradise (Strelitzia reginae ) flowers
• cabbage leaf poultice
• cattail (Typha latifolia ) juice
• chickweed (Stellaria media ) salve
• comfrey (Symphytum officinale ) juice
• evening primrose (Oenothera biennis ) oil
• heal-all (Prunella vulgaris ) juice
• honeysuckle vine flowers and leaves
• marigold (Calendula officinalis )
• marsh mallow (Althaea officinalis ) leaf poultice
• myrrh (Commiphora species) oil
• oats (Avena sativa ) bath or poultice
• onion juice
• papaya fruit
• plantain (Plantago major ) juice or poultice
• red pepper juice
• Sage (Salvia officinalis ) leaves
• St. John's wort (Hypericum perforatum )
• tea tree (Melaleuca alternifolia ) oil
• yellow dock (Rumex crispus ) tea bath

Allopathic treatment

Specific treatment of itching depends on the underlying cause. Such antihistamines as diphenhydramine (Benadryl) can help relieve itching caused by hives but won't affect itching from other causes. Most antihistamines also make people sleepy, which can help patients sleep who would otherwise be awake from the itch. Newer antihistamines that do not make people drowsy as a side effect are also available to treat itching.

Creams or ointments containing cortisone may help control itching from insect bites, contact dermatitis, or eczema. Cortisone cream should not be applied to the face unless a doctor prescribes it, and should not be used over the body for prolonged periods without a doctor's approval.

A newer medication that relieves the itching associated with burns as well as speeding the healing process is called dexpanthenol. Dexpanthenol helps to relieve the itching by preventing the affected skin from drying out.

Expected results

Most cases of itching go away when the underlying cause is treated successfully.

Prevention

Soaps are often irritating and drying to the skin and can make an itch worse. They should be avoided or used only when necessary. People who tend to have itchy skin should:

• Avoid bathing daily.
• Use lukewarm water when bathing.
• Use mild soap.
• Pat (not rub) the skin dry after bathing, leaving some water on the skin.
• Apply a moisturizer immediately after the bath but avoid lanolin products.
• Use a humidifier, particularly during heating season in colder climates.

Eating garlic and onion and taking vitamin B supplements may help to repel mosquitoes. Application of cedar, sage, pennyroyal, rosemary , artemisia, or marigold to the skin may also repel mosquitoes

Resources

BOOKS

Turkington, Carol A., and Jeffrey S. Dover. Skin Deep: An A to Z of Skin Disorders, Treatments and Health. New York: Facts on File, 1998.

Ying, Zhou Zhong, and Jin Hui De. "Cutaneous Pruritus." Clinical Manual of Chinese Herbal Medicine and Acupuncture. New York: Churchill Livingston, 1997.

PERIODICALS

Black, A. K., and M. W. Greaves. "Antihistamines in Urticaria and Angioedema." Clinical Allergy and Immunology 17 (2002): 249-286.

Ebner, F., A. Heller, F. Rippke, and I. Tausch. "Topical Use of Dexpanthenol in Skin Disorders." American Journal of Clinical Dermatology 3 (2002): 427-433.

Kandyil, R., N. S. Satya, and R. A. Swerlick. "Chronic pruritus associated with Helicobacter pylori." Journal of Cutaneous Medicine and Surgery 6 (March-April 2002): 103-108.

Nilsson, Hans-Jörgen, Anders Levinsson, and Jens Schouenborg. "Cutaneous Field Stimulation (CFS): A New Powerful Method to Combat Itch." Pain 71 (1997): 49-55.

Schmelz, M. "Itch—Mediators and Mechanisms." Journal of Dermatologic Science 28 (February 2002): 91-96.

Shenefelt, Philip D. "Hypnosis in Dermatology." Archives of Dermatology 136 (March 2000): 393-399.

Stander, S., and M. Steinhoff. "Pathophysiology of Pruritus in Atopic Dermatitis: An Overview." Experimental Dermatology 11 (February 2002): 12-24.

Tang, William Yuk Ming, Loi Yuen Chan, Kuen Kong Lo, and Tze Wai Wong. "Evaluation of the Antipruritic Role of Transcutaneous Electrical Nerve Stimulation in the Treatment of Pruritic Dermatoses." Dermatology 199 (1999): 237-241.

Yoon, S., J. Lee, and S. Lee. "The Therapeutic Effect of Evening Primrose Oil in Atopic Dermatitis Patients with Dry Scaly Skin Lesions Is Associated with the Normalization of Serum Gamma-Interferon Levels." Skin Pharmacology and Applied Skin Physiology 15 (January-February 2002): 20-25.

ORGANIZATIONS

American Academy of Dermatology. 930 N. Meacham Rd., PO Box 4014, Schaumburg, IL 60168. (708) 330-0230.

Belinda Rowland

Rebecca J. Frey, PhD

Itching

Definition

Itching is an intense, distracting irritation or tickling sensation that may be felt all over the skin's surface, or confined to just one area. The medical term for itching is pruritus.

Description

Itching instinctively leads most people to scratch the affected area. Different people can tolerate different amounts of itching, and anyone's threshold of tolerance can be changed due to stress , emotions, and other factors. In general, itching is more severe if the skin is warm, and if there are few distractions. This is why people tend to notice itching more at night.

Causes and symptoms

The biology underlying itching is not fully understood. It is believed that itching results from the interactions of several different chemical messengers. Although itching and pain sensations were at one time thought to be sent along the same nerve pathways, researchers reported the discovery in 2003 of itch-specific nerve pathways. Nerve endings that are specifically sensitive to itching have been named pruriceptors.

Research into itching has been helped by the recent invention of a mechanical device called the Matcher, which electrically stimulates the patient's left hand. When the intensity of the stimulation equals the intensity of itching that the patient is experiencing elsewhere in the body, the patient stops the stimulation and the device automatically records the measurement. The Matcher was found to be sensitive to immediate changes in the patient's perception of itching as well as reliable in its measurements.

Stress and emotional upset can make itching worse, no matter what the underlying cause. If emotional problems are the primary reason for the itch, the condition is known as psychogenic itching. Some people become convinced that their itch is caused by a parasite; this conviction is often linked to burning sensations in the tongue, and may be caused by a major psychiatric disorder.

Generalized itching

Itching that occurs all over the body may indicate a medical condition such as diabetes mellitus , liver disease, kidney failure, jaundice, thyroid disorders (and rarely, cancer ). Blood disorders such as leukemia, and lymphatic conditions such as Hodgkin's disease may sometimes cause itching as well.

Some people may develop an itch without a rash when they take certain drugs (such as aspirin , codeine, cocaine); others may develop an itchy red “drug rash” or hives because of an allergy to a specific drug. Some medications given to cancer patients may also cause itching.

Many skin conditions cause an itchy rash. These include:

• atopic dermatitis
• contact dermatitis
• dermatitis herpetiformis (occasionally)
• eczema
• fungus infections (such as athlete's foot)
• hives (urticaria)
• insect bites
• lice
• lichen planus
• neurodermatitis (lichen simplex chronicus)
• psoriasis (occasionally)
• scabies

On the other hand, itching all over the body can be caused by something as simple as bathing too often, which removes the skin's natural oils and may make the skin too dry and scaly.

Localized itching

Specific itchy areas may occur if a person comes in contact with soap, detergents, and wool or other rough-textured, scratchy material. Adults who have hemorrhoids , anal fissure, or persistent diarrhea may notice itching around the anus (called “pruritus ani”).

Intense itching in the external genitalia in women (“pruritus vulvae”) may be due to candidiasis, hormonal changes, vaginal suppositories, ointments, or deodorants.

It is also common for older people to suffer from dry, itchy skin (especially on the back) for no obvious reason.

Diagnosis

Itching is a symptom that is quite obvious to its victim. Someone who itches all over should seek medical care. Because itching can be caused by such a wide variety of triggers, a complete physical exam and medical history will help diagnose the underlying problem. A variety of blood and stool tests may help determine the underlying cause.

Treatment Antihistamines such as diphenhydramine (Benadryl) can help relieve itching caused by hives, but will not affect itching from other causes. Most antihistamines also make people sleepy, which can help patients sleep who would otherwise be awake from the itch.

Specific treatment of itching depends on the underlying condition that causes it. In general, itchy skin should be treated very gently. While scratching may temporarily ease the itch, in the long run scratching just makes it worse. In addition, scratching can lead to an endless cycle of itch—scratch—more itching.

To avoid the urge to scratch, a person can apply a cooling or soothing lotion or cold compress when the urge to scratch occurs. Soaps are often irritating to the skin, and can make an itch worse; they should be avoided, or used only when necessary.

Creams or ointments containing cortisone may help control the itch from insect bites, contact dermatitis or eczema. Cortisone cream should not be applied to the face unless a doctor prescribes it.

Probably the most common cause of itching is dry skin . There are a number of simple things a person can do to ease the annoying itch:

• Do not wear tight clothes.
• Avoid synthetic fabrics.
• Do not take long baths.
• Wash the area in lukewarm water with a little baking soda.
• For generalized itching, take a lukewarm shower.
• Try a lukewarm oatmeal (or Aveeno) bath for generalized itching.
• Apply bath oil or lotion (without added colors or scents) right after bathing.

Itching may also be treated with whole-body medications. In addition to antihistamines, some of these systemic treatments include:

• tricyclic antidepressants
• sedatives or tranquilizers
• such selective serotonin reputake inhibitors as paroxetine (Paxil) and sertraline (Zoloft)
• binding agents (such as cholestyramine which relieves itching associated with kidney or liver disease)
• aspirin
• cimetidine

People who itch as a result of mental problems or stress should seek help from a mental health expert.

Alternative and complementary therapies

A well-balanced diet that includes carbohydrates , fats, minerals, proteins, vitamins , and liquids will help to maintain skin health. Capsules that contain eicosapentaenoic acid, which is obtained from herring, mackerel, or salmon, may help to reduce itching. Vitamin A plays an important role in skin health. Vitamin E (capsules or ointment) may reduce itching. Patients should check with their treating physician before using supplements.

Homeopathy has been reported to be effective in treating systemic itching associated with hemodialysis.

Baths containing oil with milk or oatmeal are effective at relieving localized itching. Evening primrose oil may soothe itching and may be as effective as corticosteroids. Calendula cream may relieve short-term itching. Other herbal treatments that have been recently reported to relieve itching include sangre de drago, a preparation made with sap from a South American tree; and a mixture of honey, olive oil, and beeswax.

Distraction, music therapy, relaxation techniques, and visualization may be useful in relieving itching. Ultraviolet light therapy may relieve itching associated with conditions of the skin, kidneys, blood, and gallbladder. There are some reports of the use of acupuncture and transcutaneous electrical nerve stimulators (TENS) to relieve itching.

Prognosis

Most cases of itching go away when the underlying cause is treated successfully.

KEY TERMS

Atopic dermatitis —An intensely itchy inflammation often found on the face of people prone to allergies.

Creeping eruption —Itchy irregular, wandering red lines on the foot made by burrowing larvae of the hookworm family and some roundworms.

Dermatitis herpetiformis —A chronic very itchy skin disease with groups of red lesions that leave spots behind when they heal. It is sometimes associated with cancer of an internal organ.

Eczema —A superficial type of inflammation of the skin that may be very itchy and weeping in the early stages; later, the affected skin becomes crusted, scaly, and thick. There is no known cause.

Hodgkin's disease —A type of cancer characterized by a slowly-enlarging lymph tissue; symptoms include generalized itching.

Lichen planus —A noncancerous, chronic itchy skin disease that causes small, flat purple plaques on wrists, forearm, ankles.

Neurodermatitis —An itchy skin disease (also called lichen simplex chronicus) found in nervous, anxious people.

Pruriceptors —Nerve endings specialized to perceive itching sensations.

Pruritus —The medical term for itching.

Psoriasis —A common, chronic skin disorder that causes red patches anywhere on the body. Occasionally, the lesions may itch.

Scabies —A contagious parasitic skin disease characterized by intense itching.

Swimmer's itch —An allergic skin inflammation caused by a sensitivity to flatworms that die under the skin, causing an itchy rash.

Prevention

There are certain things people can do to avoid itchy skin. Patients who tend toward itchy skin should:

• Avoid a daily bath.
• Use only lukewarm water when bathing.
• Use only gentle soap.
• Pat dry, not rub dry, after bathing, leaving a bit of water on the skin.
• Apply a moisture-holding ointment or cream after the bath.
• Use a humidifier in the home.

Patients who are allergic to certain substances, medications, and so on can avoid the resulting itch if they avoid contact with the allergen. Avoiding insect bites, bee stings, poison ivy and so on can prevent the resulting itch. Treating sensitive skin carefully, avoiding overdrying of the skin, and protecting against diseases that cause itchy rashes are all good ways to avoid itching.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD, editors. “Pruritus.” Section 10, Chapter 109. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

PERIODICALS

Al-Waili, N. S. “Topical Application of Natural Honey, Beeswax and Olive Oil Mixture for Atopic Dermatitis or Psoriasis: Partially Controlled, Single-Blinded Study.” Complementary Therapies in Medicine 11 (December 2003): 226–234.

Browning, J., B. Combes, and M. J. Mayo. “Long-Term Efficacy of Sertraline as a Treatment for Cholestatic Pruritus in Patients with Primary Biliary Cirrhosis.” American Journal of Gastroenterology 98 (December 2003): 2736–2741.

Cavalcanti, A. M., L. M. Rocha, R. Carillo Jr., et al. “Effects of Homeopathic Treatment on Pruritus of Haemodialysis Patients: A Randomised Placebo-Controlled Double-Blind Trial.” Homeopathy 92 (October 2003): 177–181.

Ikoma, A., R. Rukwied, S. Stander, et al. “Neurophysiology of Pruritus: Interaction of Itch and Pain.” Archives of Dermatology 139 (November 2003): 1475–1478.

Jones, K. “Review of Sangre de Drago (Croton lechleri)—A South American Tree Sap in the Treatment of Diarrhea, Inflammation, Insect Bites, Viral Infections, and Wounds: Traditional Uses to Clinical Research.” Journal of Alternative and Complementary Medicine 9 (December 2003): 877–896.

Ochoa, J. G. “Pruritus, a Rare but Troublesome Adverse Reaction of Topiramate.” Seizure 12 (October 2003):516–518.

Stener-Victorin, E., T. Lundeberg, J. Kowalski, et al. “Perceptual Matching for Assessment of Itch; Reliability and Responsiveness Analyzed by a Rank-Invariant Statistical Method.” Journal of Investigative Dermatology 121 (December 2003): 1301–1305.

Zylicz, Z., M. Krajnik, A. A. Sorge, and M. Costantini. “Paroxetine in the Treatment of Severe Non-Dermatological Pruritus: A Randomized, Controlled Trial.” Journal of Pain and Symptom Management 26 (December 2003): 1105–1112.

Carol A. Turkington Rebecca J. Frey Ph.D.

Itching

Definition

Itching is an intense, distracting irritation or tickling sensation that may be felt all over the skin's surface or confined to just one area. The medical term for itching is pruritus.

Description

Itching instinctively leads most people to scratch the affected area. Different people can tolerate different amounts of itching, and the threshold of tolerance can change due to stress, emotions, and other factors. In general, itching is more severe if the skin is warm and if there are few distractions. This is why people tend to notice itching more at night.

Demographics

It is common for children to be itchy occasionally. Prolonged itching in a specific location and generalized itching in many different areas of the body are less common.

Causes and symptoms

The reason for the sensation of itching is not well understood. While itching is the most noticeable symptom in many skin diseases, it does not necessarily mean that a person who feels itchy has a disease.

Stress and emotional upset can make itching worse, no matter what the underlying cause. Itching is often worse at night or at times when there are no distractions. If emotional problems are the primary reason for the itch, the condition is known as psychogenic itching. Some people become convinced that their itch is caused by a parasite; this conviction is often linked to burning sensations in the tongue and may be caused by a major psychiatric disorder.

Generalized itching

Itching that occurs all over the body may indicate a medical condition such as diabetes mellitus , liver disease, kidney failure, jaundice , thyroid disorders, or rarely, cancer . Blood disorders such as leukemia and lymphatic conditions such as Hodgkin's disease may sometimes cause itching as well.

Some children may develop an itch without a rash when they take certain drugs such as aspirin or codeine. Others may develop an itchy red drug rash or hives because of an allergy to a specific drug such as penicillin.

Itching also may be caused when any of the family of hookworm larvae penetrate the skin. This includes swimmer's itch and creeping eruption caused by cat or dog hookworm and ground itch caused by the true hookworm.

Many skin conditions cause an itchy rash. These include:

• atopic dermatitis
• contact dermatitis
• dermatitis herpetiformis (occasionally)
• eczema
• fungus infections (such as athlete's foot)
• hives (urticaria)
• insect bites
• lice
• lichen planus
• neurodermatitis (lichen simplex chronicus)
• psoriasis (occasionally)
• scabies

Itching all over the body can be caused by something as simple as bathing too often, which removes the skin's natural oils and may make the skin too dry.

Localized itching

Specific itchy areas may occur if a person comes in contact with soap, detergents, or wool or other rough-textured, scratchy material. Adults who have hemorrhoids, anal fissure, or persistent diarrhea may notice itching around the anus (called pruritus ani). When children itch in this area, the cause is most likely pinworms .

Intense itching in the external genitalia in women (pruritus vulvae) may be due to candidiasis (yeast), hormonal changes, or the use of certain spermicides or vaginal suppositories, ointments, or deodorants.

When to call the doctor

If the child is itchy all over or has a localized itch in combination with a rash, fever , infection, or is acting sick, the doctor should be contacted.

Diagnosis

Itching is a symptom that is obvious to its victim. Because itching can be caused by such a wide variety of triggers, a complete physical examination and medical history will help diagnose the underlying problem. A variety of blood and stool tests may be needed to help the doctor to determine the cause of the itch.

Treatment

Antihistamines such as diphenhydramine (Benadryl) can help relieve itching caused by hives but will not relieve itching from other causes. Most antihistamines also make people sleepy, which can help children sleep who would otherwise be awakened by the itch.

Specific treatment of itching depends on the underlying condition that causes it. In general, itchy skin should be treated very gently. While scratching may temporarily ease the itch, in the long run scratching makes the itch worse and can lead to an endless cycle in which scratching an itch makes it more itchy.

To avoid the urge to scratch, a cooling or soothing lotion or cold compress can be applied when the urge to scratch occurs. Soaps are often irritating to the skin and can make an itch worse; they should be avoided or used only when necessary.

Creams or ointments containing cortisone may help control the itch from insect bites, contact dermatitis, or eczema. Cortisone cream should not be applied to the face unless prescribed by a doctor.

Probably the most common cause of itching is dry skin. There are a number of simple things that can be done to ease the annoying itch:

• Do not wear tight clothes.
• Avoid synthetic fabrics.
• Take shorter baths.
• Wash the area in lukewarm water with a little baking soda.
• For generalized itching, take a lukewarm shower or oatmeal (or Aveeno) bath.
• Apply bath oil or lotion (without added colors or scents) right after bathing.

Children who itch as a result of mental problems or stress may benefit from seeing a mental health expert.

Prognosis

Most cases of itching resolve successfully when the underlying cause is treated.

Prevention

There are certain things people can do to avoid itchy skin. Children who tend toward itchy skin should take the following steps:

KEY TERMS

Atopic dermatitis —An intensely itchy inflammation often found on the face, in the bend of the elbow, and behind the knees of people prone to allergies. In infants and young children, this condition is called infantile eczema.

Creeping eruption —Itchy, irregular, wandering red lines on the foot made by burrowing larvae of the hookworm family and some roundworms.

Dermatitis herpetiformis —A chronic, very itchy skin disease with groups of red lesions that leave spots behind when they heal.

Eczema —A superficial type of inflammation of the skin that may be very itchy and weeping in the early stages; later, the affected skin becomes crusted, scaly, and thick.

Hodgkin's disease —One of two general types of lymphoma (cancers that arise in the the lymphatic system and can invade other organs), Hodgkin's disease is characterized by lymph node enlargement and the presence of a large polyploid cells called Reed-Sternberg cells.

Lichen planus —A noncancerous, chronic itchy skin disease that causes small, flat purple plaques on wrists, forearm, ankles.

Neurodermatitis —An itchy skin disease (also called lichen simplex chronicus) found in nervous, anxious people.

Psoriasis —A chronic, noncontagious skin disease that is marked by dry, scaly, and silvery patches of skin that appear in a variety of sizes and locations on the body.

Scabies —A contagious parasitic skin disease caused by a tiny mite and characterized by intense itching.

Swimmer's itch —An allergic skin inflammation caused by a sensitivity to flatworms that die under the skin, resulting in an itchy rash.

• Avoid a daily bath.
• Use only lukewarm water when bathing.
• Use only gentle soap.
• Pat dry, not rub dry, after bathing, leaving a bit of water on the skin.
• Apply a moisture-holding ointment or cream after the bath.
• Use a humidifier in the home.

Children who are allergic to certain substances, medications, or foods can avoid the resulting itch if they avoid contact with the allergen. Avoiding insect bites, bee stings , poison ivy , and similar plants can prevent the resulting itch. Treating sensitive skin carefully, avoiding overdrying of the skin, and protecting against diseases that cause itchy rashes are all good ways to avoid itching.

Parental concerns

Children who are itchy should have their finger nails cut short to help ensure that they do not scratch the itchy area enough to create breaks in the skin. Scratching until the skin is broken can lead to infection. Itching can be very frustrating, and, if it is severe, it can interfere with normal activities such as studying or sleeping. Itching is a symptom of many common childhood ailments such as chickenpox and contact with poison ivy, as well as of some more serious conditions.

Resources

BOOKS

Fleischer, Alan B., Jr. The Clinical Management of Itching. New York: Parthenon Publishing Group, 2000.

Yosipovitch, et al., eds. Itch: Basic Mechanisms and Therapy. New York: Marcel Dekker, 2004.

PERIODICALS

Moses, Scott. "Pruritus." American Family Physician 68 (September 15, 2003): 1135.

Yosipovitch, Gil, and Jennifer L. Hundley. "Practical Guidelines for Relief of Itch." Dermatology Nursing 16 (August 2004): 325–30.

Tish Davidson, A.M. Carol A. Turkington

Itching

Description

Itching, also called pruritus, is an unpleasant sensation of the skin that causes a person to scratch or rub the area to find relief. Itching can be confined to one spot (localized) or over the whole body (generalized). Severe scratching can injure the skin causing redness, bumps, and scratches. Injured skin is prone to infection.

Itching can profoundly affect quality of life. It can torment the patient and cause discomfort, stress, loss of sleep, concentration difficulty, and constant concern.

Causes

The biology underlying itching is not fully understood. It is believed that itching results from the interactions of several different chemical messengers. Although they are quite different sensations, itch and pain signals are sent along the same nerve pathways.

Itching is associated with a variety of factors including skin diseases, blood diseases, emotions, and drug reactions as well as by cancer and cancer treatments. Itching can be a symptom of cancer including Hodgkin's disease , non-Hodgkin's lymphomas , leukemia, Bowen's disease , multiple myeloma , central nervous system (brain and spinal cord) tumors, germ cell tumors , and invasive squamous cell carcinoma. The buildup of toxins in the blood, caused by kidney, gallbladder, and liver disease, can cause itching. Cancer treatments that are associated with itching are: radiation therapy , chemotherapy , and biological response modifiers (drugs that improve the patient's immune system). Skin reactions are more severe when both chemotherapy and radiation therapy are used. Patients treated with bone marrow transplantation may develop itching resulting from graft-vs.-host disease . Itching can be caused by infection.

General medications, which may be used by cancer patients, can cause itching. Itching can be caused by drug reactions from antibiotics , corticosteroids , hormones, and pain relievers (analgesics).

Itching can be a sign that the patient is very sensitive to a particular chemotherapy drug. Chemotherapy drugs and biological response modifiers that can cause itching include:

• allopurinol
• aminoglutethimide
• bleomycin
• carmustine
• chlorambucil
• cyclophosphamide
• cytarabine
• daunorubicin
• doxorubicin
• hydroxyurea
• idarubicin
• interleukin (aldesleukin )
• mechlorethamine
• megestrol acetate
• mitomycin-C
• tamoxifen

Itching commonly occurs during radiation therapy. Parts of the body that are particularly sensitive to radiation are the underarms, groin, abdomen, breasts, buttocks, and skin around the genitals (perineum) and anus (perianal). Itching is usually caused by skin dryness when the oil (sebaceous) glands are damaged by the radiation. Radiation also causes skin darkening, redness, and skin shedding, which can all cause itching.

Itching caused by cancer usually disappears once the cancer is in remission or cured. Chemotherapy-induced itching usually disappears within 30 to 90 minutes after the drug has been administered. Itching caused by radiation therapy will resolve once the injured skin has healed.

Treatments

There are three aspects in the treatment of itching: managing the underlying cancer, maintaining skin health, and relief of itching.

Patients should avoid the particular things that cause or worsen their itching. Also, patients can take measures to maintain skin health. Suggestions include:

• taking short baths in warm water
• using mild soaps and rinsing well
• applying bath oil or moisturizing cream after bathing
• avoiding use of cosmetics, perfumes, deodorants, and starch-based powders
• avoiding wool and other harsh fabrics
• using mild laundry detergents and rinsing thoroughly
• avoiding use of dryer anti-static sheets
• wearing loose-fitting cotton clothing
• avoiding high-friction garments such as belts, pantyhose, and bras
• maintaining a cool environment with a 30% to 40% humidity level
• using cotton sheets
• avoiding vigorous exercise (if sweating causes itching)
• avoiding skin products that are scented or contain alcohol or menthol

To reduce skin injury caused by scratching the patient should keep fingernails short, wear soft cotton mittens and socks at night, and keep the hands clean. Gently rubbing the skin around the itch or applying pressure or vibration to the itchy spot may reduce itching. Using a soft infant toothbrush to gently stroke the itchy area may relieve itching. Itching may be relieved by applying a cool washcloth or ice to the itchy area.

The most effective way to relieve itching is to treat the underlying disease. Sometimes, itching disappears as soon as a tumor is treated or removed.

Itching may be relieved by applying any of a variety of different products to the skin. The patient may need to try several before the most effective one is found. The patient's physician should be consulted before any anti-itch products are used. Topical treatments include:

• Corticosteroids, such as hydrocortisone, reduce inflammation and itching.
• Calamine lotions can cool and soothe itchy skin. These products can be drying, which may be helpful for weeping or oozing rashes.
• Antihistamine creams stop itching that is associated with the chemical messenger histamine.
• Moisturizers treat dry skin which helps to relieve itching. Moisturizers that are recommended to cancer patients include brand names Alpha Keri, Aquaphor, Eucerin, Lubriderm, Nivea, Prax, and Sarna. Moisturizers should be applied after bathing and at least two or three times daily.
• Gels that contain a numbing agent (e.g. lidocaine) can be used on some parts of the body.

Itching may be treated with whole-body medications. Some of these systemic treatments include:

• antihistamines
• tricyclic antidepressants
• sedatives or tranquilizers
• binding agents (such as cholestyramine which relieves itching associated with kidney or liver disease).
• aspirin
• cimetidine

Alternative and complementary therapies

A well-balanced diet that includes carbohydrates, fats, minerals, proteins, vitamins , and liquids will help to maintain skin health. Capsules that contain eicosapentaenoic acid, which is obtained from herring, mackerel, or salmon, may help to reduce itching. Vitamin A plays an important role in skin health. Vitamin E (capsules or ointment) may reduce itching. Patients should check with their treating physician before using supplements.

Baths containing oil with milk or oatmeal are effective at relieving localized itching. Evening primrose oil may soothe itching and may be as effective as corticosteroids. Calendula cream may relieve short-term itching.

Distraction, music therapy, relaxation techniques, and visualization may be useful in relieving itching. Ultraviolet light therapy may relieve itching associated with conditions of the skin, kidneys, blood, and gallbladder. There are some reports of the use of acupuncture and transcutaneous electrical nerve stimulators (TENS) to relieve itching.

Belinda Rowland, Ph.D.

KEY TERMS

Chemical messengers

—Chemicals that transmit messages from one place to another.

Generalized itching

—Itching that occurs over the whole body.

Histamine

—A chemical messenger that can be associated with itching.

Localized itching

—Itching that is confined to one spot.