Contact dermatitis

Definition

Contact dermatitis is the name for any skin inflammation that occurs when the skin's surface comes in contact with a substance originating outside the body. There are two major categories of contact dermatitis, irritant and allergic. Irritant dermatitis is essentially a direct injury to the skin, caused by such compounds as acids, alkalis, phenol, and detergents. The immune system is not involved in irritant dermatitis, and the person's skin is damaged without prior sensitization.

In allergic dermatitis, however, the patient's skin reacts to a substance to which it has become sensitized. A third type of dermatitis, photo contact dermatitis, is triggered by exposure of the skin to light following the application of certain cosmetics or chemicals. Photo contact dermatitis may be either irritant or allergic.

Description

Contact dermatitis may be either an acute or chronic skin disorder. In general, allergic contact dermatitis is more severe and acute in its onset than irritant contact dermatitis. In irritant contact dermatitis, the rash is usually limited to the area that was exposed to the substance, whereas in allergic contact dermatitis, the rash often spreads beyond the area directly exposed to the allergen. Irritant contact dermatitis most commonly affects the hands, while allergic contact dermatitis may be found on almost any part of the body, including the armpits and genitals. Allergic contact dermatitis is more likely to involve swelling of the skin and the development of small fluid-filled blisters than irritant contact dermatitis.

Photo contact dermatitis is usually limited to the area of skin exposed to direct light. If the substance that was applied to the skin was changed to an irritant by light exposure, the primary symptom is a burning sensation resembling sunburn . If the substance was changed to an allergen, the primary sensation is itching .

Demographics

Contact dermatitis is a common complaint in people of all ages, in part because of the large number of potential irritants and allergens in the contemporary environment. One textbook on contact dermatitis runs to over 1,100 pages of descriptions of the various manufactured products and other substances that can cause these skin reactions.

In the United States, contact dermatitis ranks among the top 10 reasons for visits to primary care doctors and accounts for 7 percent of all visits to dermatologists. Every year between 10 and 50 million Americans in all age groups develop an allergic rash following contact with poison ivy or poison oak .

About 20 percent of children in the general United States population develop allergic contact dermatitis at some point prior to adolescence . Between 20 percent and 35 percent of healthy children react to one or more allergens on standard patch tests. Children of parents with allergic contact dermatitis have a 60 percent greater chance of having a positive reaction on a patch test themselves.

Contact dermatitis is more likely to affect Caucasians than African, Asian, or Native Americans. People with fair skin and red hair are particularly susceptible to contact dermatitis.

With regard to sex, girls are twice as likely as boys to develop both irritant and allergic skin reactions.

Causes and symptoms

Irritant contact dermatitis

Irritant contact dermatitis (ICD) is the more commonly reported of the two kinds of contact dermatitis, and is seen in about 80 percent of cases. It can be caused by soaps, detergents, solvents, adhesives, fiberglass, and other substances that are able to directly injure the skin by breaking or removing the protective layers of the upper epidermis. Irritants remove lipids, which are fatty substances that help to maintain the integrity of skin cells; irritants also damage the skin's ability to hold water. A common form of irritant contact dermatitis in infants is diaper rash , which develops when the protective epidermal layer of the baby's skin is damaged by long periods of contact with fecal matter and urine.

Most attacks of ICD are slight and confined to the hands and forearms but can affect any part of the body that comes in contact with an irritating substance. The symptoms can take many forms: redness, itching, crusting, swelling, blistering, oozing, dryness, scaling, thickening of the skin, and a feeling of warmth at the site of contact. In extreme cases, severe blistering can occur and open sores can form. Jobs that require frequent skin exposure to water, such as hairdressing and food preparation, can make the skin more susceptible to ICD.

Thin, moist, or already damaged skin is more susceptible to ICD than thick, dry, or intact skin.

Allergic contact dermatitis

Allergic contact dermatitis (ACD) results when repeated exposure to an allergen (an allergy-causing substance) triggers an immune response that inflames the skin. There are two phases in the development of ACD: an induction phase, in which the allergen penetrates the epidermis and is processed by an antigen-presenting cell; and an elicitation phase, in which the sensitized person has a second exposure to the allergen, which produces an inflammatory response several hours or days after the second exposure. Sensitivity to the specific allergen is often lifelong.

Tens of thousands of drugs, pesticides, cosmetics, food additives, commercial chemicals, and other substances have been identified as potential allergens. Fewer than 30, however, are responsible for the majority of ACD cases. Common culprits include poison ivy, poison oak, and poison sumac ; fragrances and preservatives in cosmetics and personal care products, such latex items as gloves and condoms; and formaldehyde. Many people find that they are allergic to the nickel in inexpensive jewelry; some adolescents find that they are allergic to the metal alloys used in orthodontic braces. ACD is usually confined to the area of skin that comes in contact with the allergen. Symptoms range from mild to severe and resemble those of ICD.

Photo contact dermatitis

In photo contact dermatitis, certain substances undergo chemical changes as a result of exposure to light that transform them into either irritants or allergens. Aftershave lotions, sunscreens , and certain topical sulfa drugs may be changed into allergens, while coal tar and certain oils used in manufacturing may become irritants after light exposure.

When to call the doctor

Contact dermatitis is not a medical emergency. It can often be treated at home once the irritant or allergen has been identified. A visit to the doctor may be necessary, however, in order to identify the cause(s) as well as obtain specific recommendations for treatment.

Diagnosis

Diagnosis of contact dermatitis begins with a physical examination and asking the patient questions about his or her health and daily activities. When contact dermatitis is suspected, the doctor attempts to learn as much as possible about the child or adolescent's school, sports participation, hobbies, favorite jewelry, use of medications and cosmetics—anything that might shed light on the source of the problem. The doctor will ask when the symptoms started, whether this is the first time they occurred, whether the rash is spreading, whether the primary sensation is itching or burning, and how severe the itching or burning feels.

In some cases, an examination of the home or school may be undertaken; in one interesting case, the doctors discovered that a rash on the back of the child's thighs was an allergic reaction to nickel in the metal parts of the chairs in the child's school. If the dermatitis is mild, responds well to treatment, and does not recur, ordinarily the investigation is at an end. More difficult cases require patch testing to identify the specific allergen.

Two methods of patch testing are used in the early 2000s. The most widely used method, the Finn chamber method, employs a multiwell aluminum patch. Each well is filled with a small amount of the allergen being tested and the patch is taped to normal skin on the patient's upper back. After 48 hours, the patch is removed and an initial reading is taken. A second reading is made a few days later.

The second method of patch testing involves applying a small amount of the test substance to directly to normal skin and covering it with a dressing that keeps air out and keeps the test substance in (occlusive dressing). After 48 hours, the dressing is taken off to see if a reaction has occurred. Identifying the allergen may require repeated testing, can take weeks or months, and is not always successful. Moreover, patch testing works only with ACD, though it is considered an essential step in ruling out ICD.

In a few cases, the doctor may take a skin biopsy in order to rule out certain infectious skin diseases.

Treatment

The best treatment for contact dermatitis is to identify the allergen or irritating substance and avoid further contact with it. If the culprit is, for instance, a cosmetic, avoidance is a simple matter, but in some situations, avoidance may be impossible or force the sufferer to make drastic changes in his or her life. Barrier creams and such protective clothing as gloves, masks, and long-sleeved shirts are coping devices to reduce the chance of contact dermatitis when avoidance is impossible, though they are not always effective.

For the symptoms themselves, treatments in mild cases include cool compresses and nonprescription lotions and ointments. Diaper rash is often treated by applying various emollient preparations that restore lipids to the child's skin. In older children and adolescents, more severe cases of contact dermatitis are treated with corticosteroids applied to the skin or taken orally. Contact dermatitis that leads to a bacterial skin infection is treated with antibiotics . Although antihistamines do not cure contact dermatitis, the doctor may prescribe them to relieve severe itching.

Alternative treatment

Herbal remedies have been used for centuries to treat skin disorders including contact dermatitis. An experienced herbalist can recommend the remedies that will be most effective for an individual's condition. Among the herbs often recommended are the following:

• Burdock (Arctium lappa ) minimizes inflammation and boosts the immune system. It is taken internally as a tea or tincture (a concentrated herbal extract prepared with alcohol).
• Calendula (Calendula officinalis ) is a natural antiseptic and anti-inflammatory agent. It is applied topically in a lotion, ointment, or oil to the affected area.
• Aloe (Aloe barbadensis ) gel soothes skin irritations. The gel is applied topically to the affected area.

A homeopath treating a patient with contact dermatitis will do a thorough investigation of the individual's history and exposures before prescribing a remedy. One homeopathic remedy commonly prescribed to relieve the itching associated with contact dermatitis is Rhus toxicodendron, which is taken internally three to four times daily.

Poison ivy, poison oak, and poison sumac are common culprits in cases of allergic contact dermatitis. Within fifteen minutes of exposure to these plants, rash development may be prevented by washing the area with soap and water. The leaves of jewelweed (Impatiens spp.), which often grows near poison ivy, may neutralize the poison-ivy allergen if rubbed on the skin right after contact. Several topical remedies may help relieve the itching associated with allergic contact dermatitis, including the juice of plantain leaves (Plantago major ); a paste made of equal parts of green clay and goldenseal root (Hydrastis canadensis ); a paste made of salt, water, clay, and peppermint (Mentha piperita ) oil; and calamine lotion.

Prognosis

If the offending substance is promptly identified and avoided, the chances of a rapid and complete recovery are excellent. Otherwise, symptom management—not cure—is the best doctors can offer. Sensitivity to allergens is typically lifelong. For a few people, contact dermatitis becomes a chronic and disabling condition that can have a profound effect on quality of life.

Prevention

Avoidance or substitution of known or suspected allergens or irritating substances is the best prevention. If avoidance is difficult, barrier creams and protective clothing can be tried. Skin that comes in contact with an offending substance should be thoroughly washed as soon as possible.

Parental concerns

Parents should be concerned primarily with identifying the cause(s) of a child or adolescent's contact dermatitis, as treatment is often ineffective until the offending substance can be removed or avoided. Most cases of contact dermatitis are mild and can be treated without disrupting the child's school routine or severely affecting his or her quality of life. In some cases, parents may find it helpful to consult a dermatologist to identify the specific causes and to suggest products that can be substituted for those that are causing the skin reactions.

KEY TERMS

Antibiotics —Drugs that are designed to kill or inhibit the growth of the bacteria that cause infections.

Corticosteroids —A group of hormones produced naturally by the adrenal gland or manufactured synthetically. They are often used to treat inflammation. Examples include cortisone and prednisone.

Dermatologist —A physician that specializes in diseases and disorders of the skin.

Epidermis —The outermost layer of the human skin.

Immune response —A physiological response of the body controlled by the immune system that involves the production of antibodies to fight off specific foreign substances or agents (antigens).

Lipids —Organic compounds not soluble in water, but soluble in fat solvents such as alcohol. Lipids are stored in the body as energy reserves and are also important components of cell membranes. Commonly known as fats.

Topical —Not ingested; applied to the outside of the body, for example to the skin, eye, or mouth.

See also Diaper rash; Poison ivy, oak, and sumac; Rashes.

Resources

BOOKS

"Contact Dermatitis." Section 10, Chapter 111 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, and Robert Berkow. Whitehouse Station, NJ: Merck Research Laboratories, 2002.

Pelletier, Kenneth R. "CAM Therapies for Specific Conditions: Eczema." Part II, in The Best Alternative Medicine. New York: Simon & Schuster, 2002.

PERIODICALS

Atherton, D. J. "A Review of the Pathophysiology, Prevention, and Treatment of Irritant Diaper Dermatitis." Current Medical Research and Opinion 20 (May 2004): 645–49.

Duarte, I., et al. "Contact Dermatitis in Adolescents." American Journal of Contact Dermatitis 14 (December 2003): 200–02.

Kutting, B., et al. "Allergic Contact Dermatitis in Children: Strategies of Prevention and Risk Management." European Journal of Dermatology 14 (March-April 2004): 80–5.

Samimi, S. S., et al. "A Diagnostic Pearl: The School Chair Sign." Cutis 74 (July 2004): 27–8.

Shaw, D. W., et al. "Allergic Contact Dermatitis from Tacrolimus." Journal of the American Academy of Dermatology 50 (June 2004): 962–65.

Sood, A., et al. "Contact Dermatitis to a Limb Prosthesis." American Journal of Contact Dermatitis 14 (September 2003): 169–71.

ORGANIZATIONS

American Academy of Dermatology (AAD). PO Box 4014, Schaumburg, IL 60168–4014. Web site: <www.aad.org>.

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). 1 AMS Circle, Bethesda, MD 20892–3675. Web site: <www.niams.nih.gov>.

WEB SITES

Crowe, Mark A.. "Contact Dermatitis." eMedicine, September 1, 2004. Available online at <www.emedicine.com/ped/topic2569.htm> (accessed November 16, 2004).

OTHER

American Academy of Dermatology (AAD) Public Resources. Allergic Contact Rashes. Schaumburg, IL: AAD, 2003.

Howard Baker

Contact dermatitis

Definition

Contact dermatitis is the name given to any skin inflammation that results from surface contact. There are two kinds of contact dermatitis, irritant and allergic.

Description

Thousands of natural and synthetic substances can cause contact dermatitis, which is the most common skin condition requiring medical attention, and the foremost source of work-related disease. Florists, domestic workers, hairdressers, food preparers, and employees in heavy industry, construction, carpentry, dry cleaning, farming, health care, and the military are the people most at risk of contracting work-related contact dermatitis. Americans spend roughly $300 million a year in their quest for relief from contact dermatitis, not counting the considerable sums devoted by governments and businesses to regulating and policing the use of skin-threatening chemicals in the workplace. But exactly how many people suffer from contact dermatitis remains unclear; a 1997 article in the Journal of the American Medical Association notes that figures ranging from 1–15% have been put forward for Western industrial nations.

Causes & symptoms

Irritant contact dermatitis (ICD) is the more commonly reported of the two types of contact dermatitis, accounting for about 80% of cases. It can be caused by soaps, detergents, solvents, adhesives, fiberglass, and other substances that are able to directly injure the skin. Most attacks are mild and confined to the hands and forearms, but can affect any part of the body that comes in contact with the irritating substance. The symptoms can take many forms: redness, itching , crusting, swelling, blistering, oozing, dryness, scaliness, thickening of the skin, and a feeling of warmth at the site of contact. In extreme cases severe blistering can occur and open sores can form. Occupations that require frequent skin exposure to water , such as hairdressing and food preparation, can make the skin more susceptible to ICD.

Allergic contact dermatitis (ACD) results when repeated exposure to an allergen (an allergy-causing substance) triggers an immune response that inflames the skin. Tens of thousands of drugs, pesticides, cosmetics, food additives, commercial chemicals, and other substances have been identified as potential allergens. Fewer than 30, however, are responsible the majority of ACD cases. Common culprits include poison ivy, poison oak , and poison sumac; fragrances and preservatives in cosmetics and personal care products; latex items, including gloves and condoms; and formaldehyde. Many people find that they are allergic to the nickel in inexpensive costume jewelry. ACD is usually confined to the area of skin that comes in contact with the allergen, typically the hands or face. Symptoms range from mild to severe and resemble those of ICD. A patch test may be needed to determine which kind of contact dermatitis a person is suffering from.

Diagnosis

Diagnosis begins with a physical examination and asking the patient questions about his or her health and daily activities. When contact dermatitis is suspected, the doctor attempts to learn as much as possible about the patient's hobbies, workplace duties, use of medications and cosmetics, etc.—anything that might shed light on the source of the disease. In some cases an examination of the home or workplace is undertaken. If the dermatitis is mild, responds well to treatment, and does not recur, ordinarily the investigation is at an end. More difficult cases require patch testing to identify the specific allergen.

Two methods of patch testing are currently used. The most widely used method, the Finn chamber method, employs a multiwell aluminum patch. Each well is filled with a small amount of the allergen being tested and the patch is taped to normal skin on the patient's upper back. After 48 hours the patch is removed and an initial reading is taken. A second reading is made a few days later. The second method of patch testing involves applying a small amount of the test substance directly to normal skin and covering it with a dressing that keeps air out and keeps the test substance in (occlusive dressing). After 48 hours the dressing is taken off to see if a reaction has occurred. Identifying the allergen may require repeated testing, can take weeks or months, and is not always successful. Moreover, patch testing works only with ACD, though it is considered an essential step in ruling out ICD.

Treatment

Herbal therapy

Herbal remedies have been used for centuries to treat skin disorders, including contact dermatitis. An experienced herbalist or naturopathic doctor can recommend the remedies that will be most effective for a person's condition. Among the herbs often recommended are:

• Burdock (Arctium lappa ). Burdock is taken internally as a tea or tincture.
• Calendula (Calendula officinalis ). Calendula is a natural antiseptic and anti-inflammatory agent. It is applied topically in a lotion, ointment, or oil to the affected area.
• Aloe (Aloe barbadensis ). Aloes soothes skin irritations. Its gel is applied topically to the affected area.

Poison ivy, poison oak, and poison sumac are common culprits in cases of allergic contact dermatitis. Following exposure to these plants, the development of the characteristic rash may be prevented by washing the area with soap and water within 15 minutes of exposure. The leaves of jewelweed (Impatiens spp.), which often grows near poison ivy, may neutralize the poison ivy allergen if rubbed on the skin right after contact. Several topical herbal remedies may help relieve the itching associated with allergic contact dermatitis, including the juice of plantain leaves (Plantago major ); a paste made of equal

parts of green clay and goldenseal root (Hydrastis canadensis ); a paste made of salt, water, clay, and peppermint (Mentha piperita ) oil; and calamine lotion.

Homeopathy

A homeopath treating a patient with contact dermatitis will do a thorough investigation of the individual's history and exposures before prescribing a remedy. Common homeopathic remedies include:

• Rhus toxicodendron
• Croton tiglium
• ledum
• anacardium
• graphites
• sulfur

Allopathic treatment

The best treatment for contact dermatitis is to identify the allergen or irritating substance and avoid further contact with it. If the culprit is, for instance, a cosmetic, avoidance is a simple matter, but in some situations, such as an allergy to an essential workplace chemical for which no substitute can be found, avoidance may be impossible or force the sufferer to find new work or make other drastic changes in his or her life. Barrier creams and such protective clothing as gloves, masks, and long-sleeved shirts are ways of coping with contact dermatitis when avoidance is impossible, though they are not always effective.

For the symptoms themselves, treatments in mild cases include cool compresses and nonprescription lotions and ointments. When the symptoms are severe, corticosteroids applied to the skin or taken orally are used. Contact dermatitis that leads to a bacterial skin infection is treated with antibiotics.

Expected results

If the offending substance is promptly identified and avoided, the chances of a quick and complete recovery are excellent. Otherwise, symptom management—not cure—is the best that medical treatment can offer. For some people, contact dermatitis becomes a chronic and disabling condition that can have a profound effect on employability and quality of life.

Prevention

Avoidance of known or suspected allergens or irritating substances is the best prevention. If avoidance is difficult, barrier creams and protective clothing can be tried. Skin that comes in contact with an offending substance should be thoroughly washed, the sooner the better.

Resources

BOOKS

Swerlick, Robert A., and Thomas J. Lawley. "Eczema, Psoriasis, Cutaneous Infections, Acne, and Other Common Skin Disorders." In Harrison's Principles of Internal Medicine. Anthony S. Fauci, et al., eds. New York: McGraw-Hill, 1998.

Ullman, Dana. The Consumer's Guide to Homeopathy: The Definitive Resources for Understanding Homeopathic Medicine and Making It Work for You. New York: G.P. Putnam's Sons, 1995.

Wolf, John E., Jr. "Contact Dermatitis." In Conn's Current Therapy. Robert E. Rakel, ed. Philadelphia: W.B. Saunders, 1998.

PERIODICALS

Leung, Donald Y. M., et al. "Allergic and Immunologic Skin Disorders."Journal of the American Medical Association 278 (1997): 1914+.

Rietschel, Robert L. "Occupational Contact Dermatitis."Lancet 349 (1997): 1093+.

Mai Tran

Contact Dermatitis

Definition

Contact dermatitis is the name for any skin inflammation that occurs when the skin's surface comes in contact with a substance originating outside the body. There are two kinds of contact dermatitis, irritant and allergic.

Description

Thousands of natural and man made substances can cause contact dermatitis, which is the most common skin condition requiring medical attention and the foremost source of work-related disease. Florists, domestic workers, hairdressers, food preparers, and employees in industry, construction, and health care are the people most at risk of contracting work-related contact dermatitis. Americans spend roughly $300 million a year in their quest for relief from contact dermatitis, not counting the considerable sums devoted by governments and businesses to regulating and policing the use of skin-threatening chemicals in the workplace. But exactly how many people suffer from contact dermatitis remains unclear; a 1997 article in the Journal of the American Medical Association notes that figures ranging from 1% to 15% have been put forward for Western industrial nations.

Causes and symptoms

Irritant contact dermatitis (ICD) is the more commonly reported of the two kinds of contact dermatitis, anf is seen in about 80% of cases. It can be caused by soaps, detergents, solvents, adhesives, fiberglass, and other substances that are able to directly injure the skin. Most attacks are slight and confined to the hands and forearms, but can affect any part of the body that comes in contact with an irritating substance. The symptoms can take many forms: redness, itching, crusting, swelling, blistering, oozing, dryness, scaliness, thickening of the skin, and a feeling of warmth at the site of contact. In extreme cases, severe blistering can occur and open sores can form. Jobs that require frequent skin exposure to water, such as hairdressing and food preparation, can make the skin more susceptible to ICD.

Allergic contact dermatitis (ACD) results when repeated exposure to an allergen (an allergy-causing substance) triggers an immune response that inflames the skin. Tens of thousands of drugs, pesticides, cosmetics, food additives, commercial chemicals, and other substances have been identified as potential allergens. Fewer than 30, however, are responsible the majority of ACD cases. Common culprits include poison ivy, poison oak, and poison sumac; fragrances and preservatives in cosmetics and personal care products; latex items such as gloves and condoms; and formaldehyde. Many people find that they are allergic to the nickel in inexpensive jewelry. ACD is usually confined to the area of skin that comes in contact with the allergen, typically the hands or face. Symptoms range from mild to severe and resemble those of ICD; a patch test may be needed to determine which kind of contact dermatitis a person is suffering from.

Diagnosis

Diagnosis begins with a physical examination and asking the patient questions about his or her health and daily activities. When contact dermatitis is suspected, the doctor attempts to learn as much as possible about the patient's hobbies, workplace duties, use of medications and cosmetics, etc.-anything that might shed light on the source of the disease. In some cases, an examination of the home or workplace is undertaken. If the dermatitis is mild, responds well to treatment, and does not recur, ordinarily the investigation is at an end. More difficult cases require patch testing to identify the allergen.

Two methods of patch testing are currently used. The most widely used method, the Finn chamber method, employs a multiwell, aluminum patch. Each well is filled with a small amount of the allergen being tested and the patch is taped to normal skin on the patient's upper back. After 48 hours, the patch is removed and an initial reading is taken. A second reading is made a few days later. The second method of patch testing involves applying a small amount of the test substance to directly to normal skin and covering it with a dressing that keeps air out and keeps the test substance in (occlusive dressing). After 48 hours, the dressing is taken off to see if a reaction has occurred. Identifying the allergen may require repeated testing, can take weeks or months, and is not always successful. Moreover, patch testing works only with ACD, though it is considered an essential step in ruling out ICD.

Treatment

The best treatment for contact dermatitis is to identify the allergen or irritating substance and avoid further contact with it. If the culprit is, for instance, a cosmetic, avoidance is a simple matter, but in some situations, such as an allergy to an essential workplace chemical for which no substitute can be found, avoidance may be impossible or force the sufferer to find new work or make other drastic changes in his or her life. Barrier creams and protective clothing such as gloves, masks, and long-sleeved shirts are ways of coping with contact dermatitis when avoidance is impossible, though they are not always effective.

For the symptoms themselves, treatments in mild cases include cool compresses and nonprescription lotions and ointments. When the symptoms are severe, corticosteroids applied to the skin or taken orally are used. Contact dermatitis that leads to a bacterial skin infection is treated with antibiotics.

Alternative treatment

Herbal remedies have been used for centuries to treat skin disorders including contact dermatitis. An experienced herbalist can recommend the remedies that will be most effective for an individual's condition. Among the herbs often recommended are:

• burdock (Arctium lappa ) minimizes inflammation and boosts the immune system. It is taken internally as a tea or tincture (a concentrated herbal extract prepared with alcohol).
• calendula (Calendula officinalis ) is a natural antiseptic and anti-inflammatory agent. It is applied topically in a lotion, ointment, or oil to the affected area.
• aloe (Aloe barbadensis ) soothes skin irritations. The gel is applied topically to the affected area.

A homeopath treating a patient with contact dermatitis will do a thorough investigation of the individual's history and exposures before prescribing a remedy. One homeopathic remedy commonly prescribed to relieve the itching associated with contact dermatitis is Rhus toxicodendron taken internally three to four times daily.

Poison ivy, poison oak, and poison sumac are common culprits in cases of allergic contact dermatitis. Following exposure to these plants, rash development may be prevented by washing the area with soap and water within 15 minutes of exposure. The leaves of jewelweed (Impatiens spp.), which often grows near poison ivy, may neutralize the poison-ivy allergen if rubbed on the skin right after contact. Several topical remedies may help relieve the itching associated with allergic contact dermatitis, including the juice of plantain leaves (Plantago major ); a paste made of equal parts of green clay and goldenseal root (Hydrastis canadensis ); a paste made of salt, water, clay, and peppermint (Mentha piperita ) oil; and calamine lotion.

KEY TERMS

Antibiotics— Substances used against microorganisms that cause infection.

Corticosteroids— A group of anti-inflammatory substances often used to treat skin conditions.

Immune response— The protective reaction by the immune system against foreign antigens (substances that the body perceives as potentially dangerous). The immune system combats disease by neutralizing or destroying antigens.

Prognosis

If the offending substance is promptly identified and avoided, the chances of a quick and complete recovery are excellent. Otherwise, symptom management-not cure-is the best doctors can offer. For some people, contact dermatitis becomes a chronic and disabling condition that can have a profound effect on employability and quality of life.

Prevention

Avoidance of known or suspected allergens or irritating substances is the best prevention. If avoidance is difficult, barrier creams and protective clothing can be tried. Skin that comes in contact with an offending substance should be thoroughly washed as soon as possible.

Resources

PERIODICALS

Beltrani, Vincent S., and Vincent P. Beltrani. "Contact Dermatitis." Annals of Allergy, Asthma, and Immunology 78 (February 1997): 160-75.

Contact dermatitis

Definition

Contact dermatitis is a skin reaction or inflammation of the skin. It is caused by having direct contact with an offending agent or irritant. Contact dermatitis can happen immediately or days after coming in contact with the irritant or trigger.

Description

There are three types of contact dermatitis; irritant contact, allergic contact and photocontact. All types result in itching and swelling of the skin. It can be difficult to distinguish irritant from allergic contact dermatitis, but symptoms for allergic contact dermatitis often are delayed for 1–2 days while irritant contact and photocontact tend to occur immediately. Contact dermatitis may last for up to two to four weeks before it is resolved. Although contact dermatitis itself is not Hand of a 70 year old man affected by contact dermatitis from a rubber glove. (Dr. P. Marazzi, M.D. / Photo Researchers, Inc. Reproduced by permission.) contagious, if the skin becomes damaged from constant itching it could become infected.

In allergic contact dermatitis the immune system overreacts to a causative substance causing hyper-sensitivity. In allergic contact dermatitis the first exposure to the substance does not cause a rash but rather sensitizes the skin so that the second contact causes a reaction. Poison ivy is an example of something that causes allergic contact dermatitis. These allergic reactions can appear at any time during one's life.

In irritant contact dermatitis the causative agents directly damage the skin by removing protective barriers. Some things that cause irritant contact dermatitis include cleaning products, solvents, or detergents. This type often occurs on the hands due because that is the most likely part of the body to be exposed to cleaning. It sometimes takes several exposures to an irritant over time to cause the amount of skin damage that leads to dermatitis.

Photocontact dermatitis occurs when certain substances applied to the skin need to first be activated by sunlight to cause dermatitis. Examples include some perfumes, citrus fruits, sulfa drugs, some sunscreens, coal tar products, and shaving lotion.

If the agent causing the dermatitis is something the person is exposed to at work the term occupational contact dermatitis is used. Examples of this include certain chemicals, fuels, dyes, cleaning agents, solvents or dust.

Demographics

Although anyone can get contact dermatitis, individuals with atopic dermatitis and eczema are at greater risk of developing irritant contact dermatitis. Those living in areas of low humidity and cold temperatures have an increased incidence of contact dermatitis with the exception of cement exposure. Women are at higher risk of contact dermatitis than men and all ages are affected.

Causes and symptoms

Contact dermatitis is always the result of the skin coming in contact with either an irritant or an allergen. A common cause of contact dermatitis are plant allergens including the poisonous plants such as poison ivy and poison oak. Contact dermatitis can be caused by metals such as jewelry, cleaning solutions, detergents, cosmetics, perfumes, chemicals, rubber, and plants. Prescription drugs as well as over the counter drugs can also cause contact dermatitis. Occupational contact dermatitis can be caused by a variety of things including nickel, potassium dichromate and paraphenylenediamine. In elderly patients, the use of topical medication is a frequent cause of contact dermatitis.

It is important to note that although there are some things that tend to cause dermatitis more often than others, anything can cause contact dermatitis and it is different for everyone. It is a misnomer that dermatitis is caused by synthetic compounds and that natural compounds do not cause dermatitis.

Symptoms of contact dermatitis typically include a red rash which may be a raised rash known as hives. The skin will itch and possibly a burning sensation will be felt. Sometimes blisters can occur or dry, red patches that resemble a burn.

Allergic contact dermatitis is an allergic reaction to an allergen. The allergen binds to proteins in the skin sensitizing cells of the immune system. The first exposure to the allergen does not cause a reaction but sensitizes the immune system so that the second time the skin comes in contact with the allergen a reaction occurs. It can take several days after contact for the skin reaction to occur. Because of this it can be difficult to identify the specific allergen. Poison ivy is probably the most common allergen causing contact dermatitis. Repeated exposure to the allergen can cause more severe reactions.

Irritant contact dermatitis is caused by direct damage to the skin by an irritant. Most irritants are chemicals such as acids, alkalis, or solvents but sometimes plants such as hot peppers, garlic and tobacco can cause irritant contact dermatitis. The skin reactions occur within seconds of exposure and are more severe with longer exposure.

Photodermatitis is caused by sunlight reacting with a substance to transform it into an allergen or irritant. A common cause of photodermatitis is the oil from citrus fruit. When this is on the skin the sun alters it's nature causing dermatitis while without the sun, dermatitis does not occur. This can be caused by other plants including mulberry as well as certain drugs including sulfa drugs, thiazides and tetracycline.

Diagnosis

Diagnosis of contact dermatitis is primarily made by the appearance of the skin. The skin will appear red with swelling. Sometimes fluid-filled vesicles are present. In a chronic condition of contact dermatitis the skin can be scaly and cracked with thickening of the skin. Ruling out cellulitis is important in the diagnosis of contact dermatitis. Cellulitis is associated with pain and sometimes fever, malaise, swollen lymph nodes and a high white blood cell count. Cellulitis can be a very serious condition.

Treatment

Contact dermatitis usually resolves by itself fairly quickly with no treatment. A cold compress can help relieve some of the pain. Calamine lotion and oatmeal baths can relieve some itching. If necessary, an oral antihistamine can be taken to help relieve itching. If more treatment is needed, hydrocortisone cream can be applied in small areas of the skin.

Most cases of contact dermatitis can be treated at home. However, if symptoms make it difficult for the person to sleep, if the skin might be infected, if extreme pain is experienced or the condition does not seem to be getting better after a few days the person should seek medical advice. For more severe cases that require medical care prescription strength corticosteroids in a cream may be recommended or prescription strength antihistamines . At a later date the patient may be referred to an allergist who may do a patch test to help determine the cause of the dermatitis.

Nutrition/Dietetic concerns

None known.

Therapy

None necessary.

Prognosis

Contact dermatitis usually clears up in two to four weeks. The condition worsens with scratching so that should be avoided. Prolonged itching and scratching may lead to neurodermatitis or lichen simplex chronicus. This causes the skin to become thick and leathery in the affected areas. Scratching can also damage the skin and lead to an infection. Once the culprit that caused the dermatitis is identified it should be avoided.

Prevention

The most important thing in contact dermatitis is to identify the cause of the dermatitis and avoid it if possible. If complete avoidance is not possible, protective clothing should be worn to decrease the contact with the trigger, this might include plastic gloves or long pants. If exposure does occur the area of skin affected should be washed as soon as possible with soap and water. Barrier creams can also be applied to protect the skin. If you are not able to identify the causative agent, an allergy specialist may be consulted to do patch testing to determine the causative agent.

Caregiver concerns

The skin should be examined for damage that might be caused by excessive scratching.

Resources

OTHER

eMedicine. Contact dermatitis. http://www.emedicine.com/emerg/topic131.htm.

eMedicineHealth. http://www.emedicinehealth.com/contact_dermatitis/article_em.htm.

Mayo Clinic.com. http://www.mayoclinic.com/health/contact-dermatitis/DS00985/DSECTION=1.

Cindy L. Jones Ph.D.