Itching is a very common physical ailment and most individuals suffer some degree of itch in their life time. The medical term for itch is pruritis.
The sensation of itch is not pleasant and depending on the intensity, it may cause the individual an intense desire to rub or scratch the skin. In some cases, relief is obtained and in some cases, the relief is transient or makes the itch worse.
Most individuals have transient episodes of itching have no medical harm. However, some individuals develop an intense itch, which may be prolonged and also occur at night. This can lead to severe apprehension, anxiety and even emotional distress. The constant itching and scratching can lead to excoriations and thickening of the skin. Eventually the skin breaks down and is prone to infections.
The causes of itch are to numerous to be mentioned here.
Itching is best characterized as a transient localized area or a chronic generalized disorder.
Generalized causes of an itch include
- liver failure
- renal failure
- lice infections
- virus infections like chicken pox
- hypothyroidism (this condition causes the skin to dry up and the texture becomes rough)
- lymphomas (most lymphomas will cause a intense itch which may be more prominent on the upper body)
- neuropathic- occasionally some neurological problems may present with an itch
- Delusional ? some individuals feel that they have parasites on their body and scratch their body. This is a delusional sensation.
- Environmental irritants
- Physical urticaria
- Water related pruritus
- Insects (lice and scabies)
- Medications e.g. opioids, accutane, atropine
Localized causes of an itch include
- head or pubic lice
- pruritis ani
- athletes' foot
- Pompholyx ?this is a common type of eczema affecting the hands (cheiropompholyx), and sometimes the feet (pedopompholyx). It is also known as dyshidrotic eczema or vesicular eczema of the hands and/or feet.
- Pruritus vulvae -Pruritus vulvae is the term given to itching affecting the genital area of women
- Vulvovaginal candida : Vulvovaginal candidiasis is the name often given to Candida albicans infection of the vagina associated with a dermatitis of the vulva (an itchy rash). 'Vaginal thrush' and 'monilia' are also names for Candida albicans infection.
- Lichen sclerosus: Lichen sclerosis is a skin condition that usually affects the vulva area (the outside parts of the female genitalia) and the anal area in young girls, adolescents, and adults. Similar to other skin conditions, there are treatments available to help the symptoms.
Pruritus that is confined to a certain part of the body
Skin disorders that may cause an itch
- Allergic contact dermatitis
- Dry skin
- Urticaria : Urticaria (or hives) is a skin condition, commonly caused by an allergic reaction, that is characterized by raised red skin welts. It is also known as nettle rash or uredo. Welts from hives can appear anywhere on the body, including the face, lips, tongue, throat, and ears. Welts may vary in size from about 5 mm (0.2 inches) in diameter to the size of a dinner plate; they typically itch severely, sting, or burn, and often have a pale border.
- Atopic dermatitis
- Dermatitis herpetiformis : Dermatitis herpetiformis (DH) or Duhring's Disease, is a skin disorder often associated with celiac disease. It is a chronic, extremely itchy rash consisting of papules and vesicles. Dermatitis herpetiformis is associated with sensitivity of the intestine to gluten in the diet (celiac sprue).
- Lichen planus : Lichen planus appears as shiny, flat-topped bumps that often have an angular shape. These bumps have a reddish-purplish color with a shiny cast due to a very fine scale. The disease can occur anywhere on the skin, but often favors the inside of the wrists and ankles, the lower legs, back, and neck. The mouth, genital region, hair and nails are affected in some individuals. Thick patches may occur, especially on the shins. Blisters may rarely occur. Bumps may appear in areas of trauma on some individuals. About 20 percent of the time lichen planus of the skin causes minimal symptoms and needs no treatment. However, in many cases the itching can be constant and intense.
- Pityriasis rosea: Pityriasis rosea is a skin disease marked by patches of pink, oval rash. Although its exact cause is unknown and its onset is not linked to food, medicines or stress, it is thought that this essentially non-contagious condition is set off by a virus. Pityriasis rosea can affect members of either sex of any age. However, it is most common in females and those between the ages of 8 and 35. Symptoms only recur in 3% of the affected.
- Mycosis fungoides : Cutaneous T cell lymphoma (CTCL) is a slow growing form of cancer in which some of the body's white blood cells become malignant. These abnormal cells are drawn to the skin and some are deposited there. They are a special type of white blood cell called T-lymphocytes (T-Cells). T-cells regulate the body's immune system in its job of fighting infections and other harmful things in the body. Cutaneous T cell lymphoma usually develops slowly over many years. In the early stages skin may develop dry, dark patches on the skin, sometimes itchy, sometimes not. Often, it is misdiagnosed as psoriasis or eczema at first and only recognized after several biopsies.
Hormonal: A significant number of women develop dry itchy skin during pregnancy. In some cases this may be related to the liver and more common during the later stages of pregnancy.
Itch is a common symptom of menopause.