Pruritus: Itching. Pruritus can result from drug reaction, food allergy, kidney or liver disease, cancers, parasites, aging or dry skin, contact skin reaction, such as poison ivy, and for unknown reasons.
Pruritus results from a tingling, irritating or uneasy sensation on the skin. Skin irritation and inflammation from a rash is a common cause of pruritus. Other common causes include chemical irritants, such as soap and laundry detergent; dry skin; and medication side effects. Insect stings and bites may also result in pruritus. Depending on the cause, itching may occur in one localized area or the entire body, and it may be accompanied by redness, pain, swelling, or discharge from associated lesions or pustules.
Allergic reactions can lead to itching of the skin and, sometimes, of the entire face or body. In rare cases, pruritus of the nipples is a symptom of breast cancer. Medications, including antibiotics (sulfonamides, penicillin), opiates (morphine and its derivatives), phenothiazines like chlorpromazine (Thorazine) and prochlorperazine (Compazine), or isoniazid, can all lead to pruritus. Vitamin A supplementation may also cause pruritus.
You may have itchy skin over certain small areas, such as on an arm or leg, or your whole body may itch. Itchy skin can occur without any other noticeable changes on the skin. Or it may be associated with:
♦ Bumps, spots or blisters
♦ Dry, cracked skin
♦ Leathery or scaly texture to the skin
Sometimes itchiness lasts a long time and can be intense. As you rub or scratch the area, it gets itchier. And the more it itches, the more you scratch. Breaking this itch-scratch cycle can be difficult, but continued scratching can damage your skin or cause infection.
Possible causes of itchy skin include:
♦ Dry skin. If you don’t see a crop of bright, red bumps or some other dramatic change in the itchy area, dry skin (xerosis) is a likely cause. Dry skin usually results from environmental factors such as hot or cold weather with low humidity, long-term use of air conditioning or central heating, and washing or bathing too much.
♦ Skin conditions and rashes. Many skin conditions itch, including eczema (dermatitis), psoriasis, scabies, lice, chickenpox and hives. The itching usually affects specific areas and is accompanied by other signs, such as red, irritated skin or bumps and blisters.
♦ Internal diseases. These include liver disease, malabsorption of wheat (celiac disease), kidney failure, iron deficiency anemia, thyroid problems and cancers, including leukemia and lymphoma. The itching usually affects the whole body. The skin may look otherwise normal except for the repeatedly scratched areas.
♦ Nerve disorders. Conditions that affect the nervous system such as multiple sclerosis, diabetes mellitus, pinched nerves and shingles (herpes zoster) can cause itching.
♦ Irritation and allergic reactions. Wool, chemicals, soaps and other substances can irritate the skin and cause itching. Sometimes the substance, such as poison ivy or cosmetics, causes an allergic reaction. Food allergies also may cause skin to itch.
♦ Drugs. Reactions to drugs, such as antibiotics, antifungal drugs or narcotic pain medications, can cause widespread rashes and itching.
♦ Pregnancy. During pregnancy, some women experience itchy skin, especially on the abdomen, thighs, breasts and arms. Also, itchy skin conditions, such as dermatitis, can worsen during pregnancy.
Finding the cause of the itching and treating any underlying skin disease is the first step in solving pruritus.
If a drug reaction is suspected, switching to a different medication may be helpful to reduce the itching. However, most drug reactions have a rash along with itching.
The best way to prevent pruritus is to take care of your skin. To protect skin:
♦ Use skin creams and lotions that moisturize your skin and prevent dryness.
♦ Use sunscreens regularly to prevent sunburns and skin damage.
♦ Use mild bath soap that won’t irritate your skin.
♦ Take a bath or shower in warm not hot water.
♦ Avoid certain fabrics, such as wool and synthetics, that can make skin itch. Switch to cotton clothing and bed sheets.
♦ Since warm, dry air can make skin dry, keep the thermostat in your house down and use a humidifier.
♦ To relieve itching, place a cool washcloth or some ice over the area that itches, rather than scratching.