Itch

(Latin: pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience. Modern science has shown that itch has many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response patterns are different. Pain creates a withdrawal reflex while itch leads to a scratch reflex.Unmyelinated nerve fibers for itch and pain both originate in the skin; however, information for them is conveyed centrally in two distinct systems that both use the same nerve bundle and spinothalamic
 

Causes :Scabies is one cause of itching.
Swimmer's itch
Athlete's footInfections and infestations:
Allergic reaction to contact with specific chemicals, such as urushiol, derived from poison ivy or poison oak.
Body louse. Body lice can be seen in substandard living conditions.
Cutaneous larva migrans.
Head lice, if limited to the neck and scalp.
Herpes.Insect bites, such as those from mosquitos or chiggers.
Photodermatitis – (sun)light reacts with chemicals in the skin, leading to the formation of irritant metabolites.
Pubic lice, if limited to the genital area.
Scabies especially when several other persons in close contact also itch.
Shaving, which may irritate the skin.
Swimmer's itch
Varicella (Chickenpox) Most common in young children. Highly contagious.
Environmental and allergic:
Urticaria (also called hives) usually causes itching.
Dermatological disorders:
Dandruff. (An unusually large amount of flaking is associated with this sensation.)
Scab healing; scar growth; and the development or emergence of moles, pimples and ingrown hairs from below the epidermis.
Skin conditions (such as psoriasis, eczema, sunburn, athlete's foot, hidradenitis suppurativa and many others). Most are of an inflammatory nature.
Punctate palmoplantar keratoderma.
Xerosis (dry skin). This is the most common cause,[citation needed] frequently seen in the winter and also associated with older age, frequent bathing in hot showers or baths, and high-temperature and low-humidity environments.
Medical disorders:
Diabetes Mellitus.
Hyperparathyroidism.     
Iron deficiency anemia.
Jaundice and Cholestasis. (Bilirubin is a skin irritant at high concentrations.)
Malignancy or internal cancer such as lymphoma, Hodgkin's disease.[16]
Menopause or changes in hormonal balances associated with aging.
Polycythemia, which can cause generalized itching due to increased histamine.
Thyroid illness.
Uraemia.

Homeopathic Treatment!!

Anacardium orientale: This remedy is often helpful for rashes that come from poison oak, or other kinds of contact dermatitis. An intensely itching rash with swelling and fluid-filled blisters may appear. Itching is worse from applying heat or contact with hot water.

Apis: When a rash is the result of an allergic reaction and takes the form of hives, or if a rash is very pink and swollen with burning or stinging pain, this remedy may be useful. Discomfort and swelling are relieved by cold applications.

Belladonna: This remedy is useful for conditions with sudden onset that are hot, bright red, and throbbing. Rash may be accompanied by fever.

Bryonia: A bumpy, hot, and dry rash may respond to this remedy. Discomfort may be worse from heat and touch, although applying pressure or lying on the affected side often soothes the itching. If illness accompanies the rash, the person wants to lie completely still and be left alone.

Graphites: Rashes with eruptions that ooze a sticky golden fluid, then crust over, may be relieved with this remedy. Itching is worse from warmth and worse at night.

Ledum palustre: This remedy is indicated for a puffy and swollen rash. Both the swelling and the itching are relieved by cold applications.

Natrum muriaticum: This remedy is often helpful to people with chronic rashes at the margin of the scalp or in the bends of the knees and elbows. The skin is oily in most areas, but the rash looks dry and scaly. Itching is often worse from physical exertion and the person may feel worse from being in the sun. Natrum muriaticum can also help if hives break out during emotional stress, especially grief or romantic disappointment. A person who needs this remedy often has a tendency toward herpes.

Rhus toxicodendron: A blistery rash that burns and itches intensely, and is much improved by applying heat or bathing in hot water, may be relieved by this remedy. The person usually is very restless, wanting to pace or constantly move around.

Sepia: Dry skin with a scaly reddish or brownish rash suggests a need for this remedy. The person may be chilly and better from keeping warm—but getting too warm under covers or clothing, and especially sweating, makes the itching worse.

Sulphur: Red, irritated, itchy, burning rashes that are aggravated by heat and washing may respond to this remedy. The touch of clothing, especially wool, can cause a rash or make it worse. Scratching seems irresistible, but disrupts and irritates the skin. Eruptions may be dry and scaly, or moist and infection-prone.

Urtica urens: Eruptions that resemble nettle-rash, with blotches that sting and burn intensely, may be soothed by this remedy. Scratching makes the symptoms worse. Applying cold or water may aggravate the condition. Rashes that come out from eating shellfish, from being overheated, or along with rheumatism often bring this remedy to mind