Itching
Itching, also known as pruritus, is an unpleasant sensation that provokes the urge to scratch. This sensation is activated by physical or chemical stimulation of nerve receptors in the skin and can arise from a wide range of conditions affecting various organ systems. Common skin-related causes include eczema, psoriasis, insect bites, and infections, while non-skin-related issues may stem from internal health problems such as liver disease, kidney failure, or thyroid disorders. Allergies often trigger itching in the eyes and nose, and certain malignancies, particularly lymphomas, can also result in this sensation. Psychological factors may play a role, with some individuals experiencing intense itching linked to stress or substance abuse. Treatment generally focuses on addressing the underlying cause, with options such as moisturizing lotions and antihistamines available for relief. However, it's important to note that while some treatments can alleviate itching, they may also cause drowsiness. Understanding the diverse reasons behind itching can aid in effective management and improve the quality of life for those affected.
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Itching
Also known as:Pruritus
Anatomy or system affected:Skin
Definition:An unpleasant sensation on or in the skin that causes a desire to scratch or rub the affected area.
Causes and Symptoms
Itching is elicited by the physical or chemical stimulation of nerve receptors in the skin. It can be caused by a wide variety of problems in a variety of different organ systems.
Nearly any skin lesion may itch. Skin-related causes include varied problems such as eczema, psoriasis, contact dermatitis, insect bites, bacterial infections, fungal infections, sunburn, and exposure to wool. Viral infections such as chickenpox can cause intense itching. Itching of the eyes and nose is commonly associated with allergies. Itching without a skin rash may be caused by a number of internal problems. Various endocrine problems in children associated with itching include liver disease, kidney failure, thyroid disease, and diabetes. Some malignancies, particularly lymphomas, may cause itching. Hookworms and pinworms are both internal causes of itching, as are certain drugs. Some women experience generalized itching during pregnancy.
Certain psychiatric problems are associated with itching. Patients may scratch hard enough to create deep ulcers. The intensity of the itching seems to be related to the degree of nervous tension. In addition, patients who suffer from certain psychotic states or those who abuse drugs such as cocaine may experience a deep itching sensation that they describe as bugs crawling beneath the skin.
Itching may rarely be associated with neurologic disease in which changes in sensation are interpreted by the patient as itching. Occasionally, circulatory problems will cause itching, primarily on the legs. Both of these conditions are more common in older adults than in children or young adults.
Treatment and Therapy
Treatment should be directed toward the cause of the itching. Hydration (bathing followed by moisturizing lotion) may be helpful in providing relief. When itching is the result of an allergen such as poison ivy, however, a drying agent should be used. Various medications (primarily antihistamines) may relieve itching, but most also cause significant sleepiness.
Bibliography
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Bernhard, Jeffrey D., ed. Itch: Mechanisms and Management of Pruritus. McGraw-Hill, 1994.
Fleischer, Alan B., Jr. The Clinical Management of Itching. Parthenon, 2000.
James, William D., Timothy Berger, and Dirk Elston. Andrews' Diseases of the Skin: Clinical Dermatology. 13th ed. Elsevier/Saunders, 2020.
Litin, Scott C., ed. Mayo Clinic Family Health Book. 5th ed. HarperResource, 2018.
Middlemiss, Prisca. What’s That Rash? How to Identify and Treat Childhood Rashes. Chancellor Press, 2010.
Potter, Michael F. "The Sensitivity Spectrum: Human Reactions to Bed Bug Bites." Pest Control Technology, vol. 38, no. 2, 2010, pp. 70–74.
Roth, Maria-Magdalena. "Pregnancy Dermatoses: Diagnosis, Management, and Controversies." American Journal of Clinical Dermatology, vol. 21, no. 1, 2011, pp. 25–41.
Turkington, Carol, and Jeffrey S. Dover. The Encyclopedia of Skin and Skin Disorders. 3rd ed. Facts On File, 2007.
Weedon, David. Skin Pathology. 3rd ed. Churchill Livingstone/Elsevier, 2010.