Itching Health Article

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.