Itching Health Article

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.