 Itching and pruritus
The human skin is the most vital part of the body and skin allergy is one of the most common problems seen by the dermatologist and one of the most debilitating problems experienced by patients. They can be from hives to swelling, and eczemato drug and medication rashes. Some of the common skin allergies are mentioned below.
Pruritus is defined as any itching or unpleasant sensation on the skin that provokes a desire to scratch.
| It can be a part of skin diseases or may be caused by metabolic problems such as Thyroid disease or iron deficiency.Many medications can cause itching, particularly pain medications like codeine and morphine.
| All ergic rashes
Though many types of skin rashes have been observed, not all rashes that itch arerelated to skin allergies. The most common types of allergic skin rashes are:
Eczema (atopic dermatitis)
Atopic dermatitis frequently is seen in young children, although it maydevelop in young adults, and can continue into adult life.
| The rash of a topic dermatitis occurs where a person scratches.Scratching often leads to redness, swelling and scaling of the skin. Ininfants, the rash tends to develop on the chest, cheeks and scalp. Inolder children and adults, the itchy patches are seen in theskin-folds of the elbows and behind the knees, and sometimes on theface, hands, neck, upperchest, feet and back.
| | | Urticaria and angioedema
Urticaria, commonly known as hives, are raised red bumps of various shapes and sizesthat appear on your skin. It can be seen in all age groups and typically lasts foronly minutes to hours.
The swelling that is often seen along with urticaria is called angioedema, especiallynear your eyes and lips. It may also occur on your hands, feet, genetalia and insideyour throat. AngioEdema is similar to hives but may occur deeper in the skin andtends to burn, sting or cause a tingling sensation.
|  | Severe swelling may cause your throat or tongue to block the airway,leading to loss consciousness can be dangerous and even life-threatening.
| | | Contact dermatitis
Contact dermatitis is an inflammation on skin caused by direct contact with certainirritating substances, such as cosmetics, hair dye, jewelry, metals, topical medications,dental materials, including poison ivy. Reactions may vary in the same person overtime.
Symptoms include red rash, itching, red patches, blisters and localized swellingof the skin. Contact dermatitis is typically located only in the area of skin exposedto the offending substance. However, the area with the greatest exposure reactsmore severely.
It is commonly seen on the face, especially the eyelids, neck, hands and feet. Youmay get contact dermatitis due to repeated use of certain substances like preservativesin contact lens solutions, metals, backs of watches, etc.
Although there may be no initial reaction, regular use can cause sensitivity andreaction to the product. | 
 | | | Cosmetic-induced contact dermatitis
Cosmetic-induced contact dermatitis is common,since many people use cosmetics on daily basis. One or more ingredients in soap,skin products, including deodorant are common cosmetic irritants. Symptoms generallyinclude redness, swelling, itchiness and blistering.
|  | | The rash usually develops on the skin where the cosmetic was applied.Substances like bleach or strong acids,can cause cosmetic-inducedcontact dermatitis just after one exposure. However,certain substancesmay take years for the allergy to develop on your skin after years ofusing them. | | Itching without a rash
Though itchy, your skin may not haveany visual signs of a rash. It may represent a skin disease, or even an internaldisease within the body. When the itching is limited to a certain area of the body,there may be a disease process limited to the skin. The location of the itchingoften gives a big clue of what may be causing it. |
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