Itching – Information on Itching

Itching may be caused by a skin disorder or by a disease that affects the whole body (systemic disease). Skin disorders that cause severe itching include infestations with parasites (such as scabies, mites, or lice), insect bites, hives, atopic dermatitis, and allergic dermatitis and contact dermatitis. These disorders usually also produce a rash. Systemic diseases that can cause itching include liver disease, kidney failure, lymphomas, leukemias and other blood disorders, and, occasionally, thyroid disease, diabetes, and cancer. However, itching from these diseases usually does not result in a rash.

Itching can be best described as a peculiar tingling or uneasy irritation of the skin that creates a desire to scratch the affected area. Itching is a common problem faced by many people at some or the other point in life. Itching could be the result of a variety of reasons such as allergies (to food, plants or pets), insect bites, stings, skin disease or even poor hygiene. Itching can be annoying as the skin is irritated and gives you the constant need to scratch the affected area. Constant or repeated scratching can bruise the skin, making it sore and even painful. Itching could be generalized where in the whole body is affected or localized wherein a particular area is irritated.

Moisture from sweat or diarrhea may cause itching. If the anal skin stays wet, the skin begins to break down. Some foods irritate the anus when they are expelled during a bowel movement. The most common culprits are caffeine, chocolate, beer, nuts, dairy products, and spicy food.

Itch originating in the skin is considered pruritoceptive and can be induced by a variety of stimuli, including mechanical, chemical, thermal, and electrical stimulation. The primary afferent neurons responsible for histamine induced itch are unmyelinated C-fibers. In human C-fiber nociceptors, two major classes exist: mechano-responsive nociceptors and mechano-insensitive nociceptors. Mechano-responsive nociceptors have been shown in studies to respond to mostly pain and mechano-insensitive receptors respond mostly to itch induced by histamine. However it does not explain mechanically induced itch or when itch is produced without a flare reaction which involves no histamine.

Itching is an uncomfortable irritation of the skin that causes a desire to scratch the affected area. It is a very common symptom and may affect any area of your body. You can often see a rash or a spot where it occurs. Women in the menopausal transition may experience vaginal itching due to fluctuations in estrogen levels. As estrogen levels decline in the perimenopause, the vaginal wall becomes thinner and drier, and itching may result.Some studies have shown a link between psychological stress and vaginal yeast infections. This is likely due to the fact that stress is known to have a negative effect on the immune system and could possibly increase the likelihood of getting a yeast infection.

Infections and infestations of the skin are another cause of itch. Common infectious causes of itch include a fungal infection of the crotch (tinea cruris) commonly known as jock itch, as well as vaginal itching and/or anal itching from sexually transmitted diseases (STDs) or other types of infections. Another type of parasitic infection resulting in itch is the so-called swimmer's itch. Swimmer's itch, also called cercarial dermatitis, is a skin rash caused by an allergic reaction to infection with certain parasites of birds and mammals that are released from infected snails in fresh and saltwater. Itch may also result from skin infestation by body lice, including head lice and pubic lice. Most people who have itching, however, do not have a serious underlying condition.