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Eczema




http://umm.edu/health/medical/altmed/condition/eczema

Introduction

Eczema is a chronic, inflammatory skin disorder. It can appear as blisters that crust over to become scaly, itchy rashes, or as dry, thick patches of skin with scales. The main symptom is itching, and symptoms can come and go. Although eczema is not contagious, it is very common. Estimates are that more than 15 million people in the United States have eczema. People with eczema often have a personal or family history of allergies. There is no cure, however, treatments can reduce symptoms and help prevent outbreaks.

Signs and Symptoms

The most common signs of eczema are:
  • Dry, extremely itchy skin
  • Blisters with oozing and crusting
  • Red skin around the blisters
  • Raw areas on the skin from scratching, which can cause bleeding
  • Dry, leathery areas that are either darker or lighter than their normal skin tone (called lichenification)
  • Scaling, or thickened skin
Eczema in children under 2 years old generally starts on the cheeks, elbows, or knees. In adults, it tends to be found on the inside surfaces of the knees and elbows.

Causes

Researchers don’t know for sure what causes eczema. It may be a combination of hereditary (genetic) and environmental factors. In some people, having allergies may trigger eczema. Exposure to certain irritants and allergens can make symptoms worse, as can dry skin, exposure to water, temperature changes, and stress.

Risk Factors

  • Young age -- infants and young children are most affected (about 65% of cases occur before age 1, and about 90% occur before age 5)
  • Exposing skin to harsh conditions
  • Living in a climate with low humidity
  • Personal or family history of allergies to plants, chemicals, or food
  • Not getting enough of certain vitamins and minerals (for example, zinc)
  • Living in an urban, rather than rural, area
Stress can make eczema worse. Other irritants that can make eczema worse include:
  • Wool or synthetic fibers
  • Certain soaps and detergents as well as perfumes and some cosmetics
  • Dust or sand
  • Cigarette smoke
  • Traffic related air pollution

Diagnosis

Your doctor will look at your skin and ask questions about your personal and family medical history before making a diagnosis. Your doctor may ask about stress in your life, your diet, drugs you are taking, soaps and detergents you use, and chemicals or materials you may be exposed to at work. Your doctor may perform a skin lesion biopsy (removal of a small piece of skin), but it's not always needed to make the diagnosis.

Prevention

Reducing stress, nervousness, anxiety, and depression may help prevent flares of eczema. Mind body techniques including cognitive behavioral therapy and autogenic training have been shown to help. Both techniques can also be combined with learning about eczema.
Avoiding eggs, fish, peanuts, and soy may help some people reduce flares, but it varies from person to person. Ask your doctor to help you determine if avoiding these foods in your diet might reduce how often you have a flare and how severe it is.
Although somewhat controversial, some studies show that children who are exclusively breast fed for at least 4 months are less likely to get eczema. This is particularly true when the nursing mother has avoided cow's milk in her own diet.
Some studies also suggest that babies whose mothers took probiotics (“friendly bacteria”) during pregnancy and while breastfeeding were less likely to have eczema at up to 2 years of age. Other studies found no association. More research is needed.
Preliminary studies suggest that using skin creams containing omega fatty acids can reduce the severity of eczema or prevent eczema entirely.
Other preliminary studies suggest that children who have a pet dog are significantly less likely to have eczema at age 1, or at age 2 or 3, than children who don't have a pet dog.

Treatment

The goals when treating eczema are to heal the skin, reduce symptoms, prevent skin damage, and prevent flares. Developing skin care routines, identifying what triggers flares, and avoiding these triggers are a large part of any treatment plan.

Lifestyle

  • Avoid anything that makes symptoms worse, such as allergens (things you are allergic to) and things that irritate skin. Common allergens include pollen, dust mites, and pet dander. Common skin irritants include wool, synthetic fibers, soaps and detergents, perfumes, cosmetics, lanolin, certain chemicals, such as chlorine and solvents (including mineral oil), cigarette smoke, dust, and sand.
  • Don’t scratch or rub affected areas.
  • Protect skin from rough clothing and irritants.
  • Reduce stress with relaxation techniques.
  • Keep your environment cool, with stable humidity.
Dry skin often makes the condition worse. Remember to:
  • Avoid hot baths or showers; lukewarm water is best.
  • Wash or bathe as quickly as possible to lessen water contact.
  • Use a mild soap or a nonsoap cleanser, or less soap than usual.
  • Moisturize. Apply lotion or cream within a few minutes of getting out of the shower or bath to seal the moisture in your skin.
  • Wet compresses. The wet cloth macerates vesicles, and when removed, debrides the area, preventing serum and crust from accumulating. Wet compresses should be removed after 30 minutes and replaced with a freshly soaked cloth. Otherwise, irritation may occur.
Parents can help their children by:
  • Distracting them so they don’t scratch dry skin.
  • Keeping fingernails short to reduce chances of infection from scratching.
  • Understanding that visible skin problems can cause social and emotional stress.
  • Offer support and encouragement.

Medications

  • Mild anti-itch lotions (Caladryl or Calamine) or topical corticosteroids (hydrocortisone) may soothe mild dry scaly patches.
  • Area where skin is thickened may be treated with ointments or creams that contain tar compounds (such as Psoriasin), corticosteroids, and ingredients that lubricate or soften the skin.
  • Oral corticosteroids may be prescribed to reduce inflammation in severe cases. Examples include prednisone (Deltasone) and methylprednisolone (Medrol). Rarely, in severe cases where adults have not shown improvement with oral corticosteroids, medications that suppress the immune system.
  • Your doctor may recommend antihistamines at night, such as diphenhydramine (Benadryl), may be prescribed to prevent scratching. These medications may cause drowsiness. Topical (on the skin) antihistamine preparations are also available.
  • Topical immunomodulators (TCIs) are newer drugs that are applied to the skin to reduce inflammation. They are steroid free. The most commonly prescribed TCIs are tacrolimus (Protoptic) and pimecrolimus (Elidel). Doctors recommend these drugs only after other therapies have not worked.
  • Oral antibiotics may be helpful if signs of secondary infection, such as pustules, purulent material, and crusts are present.

Surgery and Other Procedures

Phototherapy and Photochemotherapy
Treatment with ultraviolet light may help mild to moderate cases of eczema in children over age 12 and adults. Phototherapy or light therapy may be combined with a type of drug called psoralen. It is then called photochemotherapy.

Nutrition and Dietary Supplements

Many people who have eczema have food allergies, so eating a healthy diet may help reduce inflammation and allergic reactions.
Check with your doctor before giving a supplement to a child.
Avoid exposure to environmental or food allergens. Common foods that cause allergic reactions are dairy, soy, citrus, peanuts, wheat (sometimes all gluten containing grains), fish, eggs, corn, and tomatoes. There is much controversy regarding the most effective way to test for food allergies or sensitivities.
Eat fewer refined foods, and sugar. These foods contribute to inflammation in the body.
Eat more fresh vegetables, whole grains, and essential fatty acids (cold water fish, nuts, and seeds).
  • Fish oil -- In one study, people taking fish oil equal to 1.8 g of EPA (one of the omega-3 fatty acids found in fish oil) experienced significant reduction in symptoms of eczema after 12 weeks. Researchers think that may be because fish oil helps reduce leukotriene B4, an inflammatory substance that plays a role in eczema. Talk to your doctor before taking fish oil if you are taking any blood-thinning medications, and before taking a high dose. If you're taking high dose fish oil, make sure you use a brand that removes most of the vitamin A. Too much vitamin A over time can be toxic.
  • Probiotics (bifidobacteria and lactobacillus, 3 - 5 billion live organisms per day) may boost the immune system and control allergies, especially in children. However, scientific studies are mixed; more research is needed to know for sure if probiotics will help reduce eczema symptoms.
  • Evening primrose oil -- In some studies, evening primrose oil helps reduce the itching of eczema. However, other studies have found no benefit. People who take anticoagulants (blood thinners) should talk to their doctor before taking evening primrose oil, and you should always ask your doctor before taking a high dose of evening primrose oil.
  • Borage oil, like evening primrose oil, contains the essential fatty acid GLA (500-900 mg per day, in divided doses -- amount of GLA varies by supplement), which acts as an anti-inflammatory. Evidence is mixed, with some studies showing that GLA helps reduce eczema symptoms and others showing no effect. Borage, like Evening Primrose Oil can interact with blood thinners and other medications. Speak with your doctor.
  • Vitamin C (1,000 mg 2 - 4 times per day) can act as an antihistamine. In one study, it helped reduce symptoms of eczema, but more studies are needed. Rose hips or palmitate are citrus-free and hypoallergenic.
  • Bromelain (100 - 250 mg 2 - 4 times per day), an enzyme derived from pineapple, helps reduce inflammation.
  • Flavonoids, antioxidants found in dark berries and some plants, have anti-inflammatory properties, strengthen connective tissue, and may help reduce allergic reactions.

Herbs

Herbs are generally a safe way to strengthen and tone the body's systems. As with any therapy, you should work with your health care provider before starting any treatment and ask your doctor before taking any herbs. You may use herbs as dried extracts (capsules, powders, teas), glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless otherwise indicated, make teas with 1 tsp. herb per cup of hot water. Steep covered 5 - 10 minutes for leaf or flowers, and 10 - 20 minutes for roots. Drink 2 - 4 cups per day. You may use tinctures alone or in combination as noted.
  • Topical creams and salves containing one or more of the following herbs may help relieve itching and burning, and promote healing. The best evidence is for chamomile (Matricaria recutita) creams. Chickweed (Stellaria media), marigold (Calendula officinalis), and licorice (Glycyrrhia glabra) may also help, although there is little scientific evidence to back that up. One study did find a licorice cream was more effective than placebo.
  • Witch hazel (Hamamelis virginiana) cream can relieve itching. Liquid witch hazel can help with "weeping" or oozing eczema.
  • St. John’s wort (Hypericum perforatum), used as a topical cream, has shown promise in one double blind study. People with eczema who used St. John’s wort on one arm and a placebo cream on the other saw more improvement on the arm treated with St. John’s wort.
  • Traditional Chinese medicine (TCM), which uses a variety of herbs often combined with acupuncture, seemed to be effective for treating eczema in children and adults in 2 2009 studies. In one retrospective study, children with eczema who drank Erka Shizheng Herbal Tea, applied an herbal cream, took herbals baths, and had acupuncture saw their symptoms improve. In another study, adults who received individual treatment with TCM based on their eczema symptoms also saw symptoms improve. More studies are needed before doctors can recommend this treatment or can speak to its safety or effectiveness.
  • Other herbs that have traditionally been applied to the skin to treat eczema include sarsaparilla (Smilax sp.) and marshmallow (Althea officinalis).

Homeopathy

Although few studies have examined the effectiveness of specific homeopathic therapies, professional homeopaths may consider the following remedies for the treatment of eczema based on their knowledge and experience. Before prescribing a remedy, homeopaths take into account a person's constitutional -- your physical, emotional, and psychological makeup. An experienced homeopath assesses all of these factors when determining the most appropriate treatment for each individual. Any remedy that causes aggravation of symptoms should be discontinued right away.
  • Calendula -- applied to the skin, particularly if the affected area is inflamed; this remedy soothes but does not cure the skin condition.
  • Sulphur -- for redness, burning, itching, and hot skin that tends to worsen with washing and scratching.
  • Urtica urens -- for large, red rashes (particularly those related to allergies) that itch and burn intensely.
  • Rhus toxicodendron -- used as a remedy for inflamed skin resulting from direct contact with an irritating substance; some homeopaths use it to treat eczema.

Massage and Physical Therapy

One clinical study looking at essential oils for treating children with eczema found that massage with and without essential oils helped improve dry, scaly skin lesions. Children with this scaly, itchy skin problem seem to have less redness, scaling, and other symptoms if they had massage between flares. Don’t use massage when skin is actively inflamed. The essential oils most often chosen by the mothers in the study included sweet marjoram, frankincense, German chamomile, myrrh, thyme, benzoin, spike lavender, and Litsea cubeba.
Exercise
In one clinical study, regular group sporting activities improved symptoms in people who participated for 3 weeks. Exercise may improve symptoms because of the positive impact it has on emotions. Sports should be avoided during the worst stages of an outbreak.
Climatotherapy
Climatotherapy uses sunlight and water (such as the ocean) as therapy. The Dead Sea in Israel is known for its healing properties, and many people with eczema go there to sit in the sun and swim in the water. Clinical studies back up the benefits. One clinical study looked at the experience of more than 1,500 people with eczema and found that 95% of skin was cleared in people who had previous stays at the Dead Sea longer than 4 weeks.

Mind-Body Medicine

Flares of eczema are associated with anxiety and stress. Several clinical studies show that relaxation techniques can reduce the number of flares and relieve symptoms of eczema. Biofeedback seems to be particularly useful.

Other Considerations

Starting an infant on solid foods slowly and gradually may help prevent the food sensitivities that may contribute to eczema.
People who are allergic to ragweed, chrysanthemums, asters, echinacea, or feverfew should avoid chamomile because it is in the same plant family.

Pregnancy

Avoid the use of burdock and sulfur during pregnancy.

Warnings and Precautions

Chinese herbal treatments for eczema have been gaining popularity in both the United States and the United Kingdom, but you should be cautious. Some of the Chinese herbal creams have high amounts of steroid medications. In a few rare instances, the use of oral Chinese herbs (like a tea) for eczema has led to kidney damage. If you want to try TCM for your eczema, find a respected TCM practitioner and make sure your doctor knows about all herbs you are using, either orally or on your skin.

Prognosis and Complications

Although eczema can lead to complications -- such as bacterial infections of the skin and permanent scar formation -- in many cases is can be easily controlled by avoiding triggers and treating your dry, scaly patches. See your doctor if your eczema does not respond to treatment or if signs of infection (such as fever, redness, pain) occur. Often children with eczema go into remission after a period of time. The remission may last the rest of their lives, although skin may remain sensitive and dry.

Supporting Research

Abrahamsson TR, Jakobsson T, Bottcher MF, et al., Probiotics in prevention of IgE-associated eczema: a double-blind, randomized, placebo-controlled trial. J Allergy Clin Immunol. 2007;119(5):1174-80.
Anandan C, Nurmatov U, Sheikh A. Omega 3 and 6 oils for primary prevention of allergic disease: systematic review and meta-analysis. Allergy. 2009 Jun;64(6):840-8. Epub 2009 Apr 7. Review.
Anderson C, Lis-Balchin M, Kifk-Smith M. Evaluation of massage with essential oils in childhood atopic eczema. Phyother Res. 2000;14(6):452-456.
Anderson PC, Dinulos JG. Atopic dermatitis and alternative management strategies. Curr Opin Pediatr. 2009 Feb;21(1):131-8. Review.
Berger MM, Shenkin A. Vitamins and trace elements: Practical aspects of supplementation. Nutrition. 2006; 22(9):952-5.
Biagini Myers JM, Wang N, LeMasters GK, et al. Genetic and environmental risk factors for childhood eczema development and allergic sensitization in the CCAAPS cohort. J Invest Dermatol. 2010;130(2):430-7.
Billmann-Eberwein C, Rippke F, Ruzicka T, Krutmann J. Modulation of atopy patch test reactions by topical treatment of human skin with a fatty acid-rich emollient. Skin Pharmacol Appl SkinPhysiol. 2002;15(2):100-104.
Boyle RJ, Bath-Hextall FJ, Leonardi-Bee J, Murrell DF, Tang ML. Probiotics for the treatment of eczema: a systemic review. Clin Exp Allergy. 2009;39(8):1117-27.
Bruno EJ Jr, Ziegenfuss TN, Landis J. Vitamin C: research update. Curr Sports Med Rep. 2006; 5(4):177-81.
Byremo G, Rod G, Carlsen KH. Effect of climatic change in children with atopic eczema. Allergy. 2006;61(12):1403-10.
Cabrera C, Artacho R, Gimenez R. Beneficial effects of green tea -- a review. J Am Coll Nutr. 2006;25(2):79-99.
Doron S, Gorbach SL. Probiotics: their role in the treatment and prevention of disease. Expert Rev Anti Infect Ther. 2006; 4(2):261-75.
Dryden GW Jr, Deaciuc I, Arteel G, McClain CJ. Clinical implications of oxidative stress and antioxidant therapy. Curr Gastroenterol Rep. 2005;7(4):308-16.
Ernst E, Huntley A. Tea tree oil: a systematic review of randomized clinical trials. ForschKomplementarmed Klass Naturheilkd. 2000; 7(1):17-20.
Ernst E. Adverse effects of herbal drugs in dermatology. Br J Dermatol. 2000;143(5):923-929.
Fleischer AB Jr, Abramovits W, Breneman D, Jaracz E; US/Canada tacrolimus ointment study group. Tacrolimus ointment is more effective than pimecrolimus cream in adult patients with moderate to very severe atopic dermatitis. J Dermatol Treat. 2007;18(3):151-7.
Furuhjelm C, Warstedt K, Larsson J, Fredriksson M, Böttcher MF, Fälth-Magnusson K, Duchén K. Fish oil supplementation in pregnancy and lactation may decrease the risk of infant allergy. Acta Paediatr. 2009 Sep;98(9):1461-7.
Habif. Clinical Dermatology. 5th ed. St. Louis, Mo: Mosby, An Imprint of Elsevier; 2009.
Harari M, Shani J, Seidl V, Hristakieva E. Climatotherapy of atopic dermatitis at the Dead Sea: demographic evaluation and cost-effectiveness. Int J Dermatol. 2000;39(1):59-69.
Horrobin DF. Essential fatty acid metabolism and its modification in atopic eczema. Am J Clin Nutr. 2000;71(1 Suppl):367S-72S.
Kalliomaki M, Kirjavainen P, Eerola E, Kero P, Salminen S, Isolauri E. Distinct patterns of neonatal gut microflora in infants in whom atopy was and was not developing. J Allergy Clin Immunol. 2001;107(1):129-134.
Kalliomaki M, Salminen S, Arvilommi H, Kero P, Koskinen P, Isolauri E. Probiotics in primary prevention of atopic disease: a randomized placebo controlled trial. Lancet. 2001;357(9262):1076-1079.
Karamfilov T, Elsner P. Sports as a risk factor and therapeutic principle in dermatology [article in German]. Hautarzt. 2002;53(2):98-103.
Kim JY, Kwon JH, Ahn SH, et al. Effect of probiotic mix (Bifidobacterium bifidum, Bifidobacterium lactis, Lactobacillus acidophilus) in the primary prevention of eczema: a double-blind, randomized, placebo-controlled trial. Pediatr Allergy Immunol. 2010;21(2Pt2):e386-93.
Kramer U, Sugiri D, Ranft U, et al. Eczema, respiratory allergies, and traffic-related air pollution in birth cohorts from small-town areas. J Dermatol Sci. 2009;56(2):99-105.
Langan SM, Williams HC. What causes worsening of eczema? A systematic review. Br J Dermatol. 2006;155(3):504-14.
Linde K, Hondras M, Vickers A, ter Riet G, Melchart D. Systematic reviews of complementary therapies - an annotated bibliography. Part 3: homeopathy. BMC Complement Altern Med. 2001; 1:4.
Magin PJ, Adams J, Heading GS, Pond DC, Smith W. Complementary and alternative medicine therapies in acne, psoriasis, and atopic eczema: results of a qualitative study of patients' experiences and perceptions. J Altern Complement Med. 2006;12(5):451-7.
Meding B, Alderling M, Wrangsjo K. Tobacco smoking and hand eczema: a population-based study. Br J Dermatol. 2010;163(4):752-6.
Morse NL, Clough PM. A meta-analysis of randomized, placebo-controlled clinical trials of Efamol evening primrose oil in atopic eczema. Where do we go from here in light of more recent discoveries? Curr Pharm Biotechnol. 2006;7(6):503-24.
Oien T, Storrø O, Johnsen R. Do early intake of fish and fish oil protect against eczema and doctor-diagnosed asthma at 2 years of age? A cohort study. J Epidemiol Community Health. 2009 Aug 13. [Epub ahead of print]
Osborn DA, Sinn J. Soy formula for prevention of allergy and food intolerance in infants. Cochrane Database Syst Rev. 2006;(4):CD003741.
Prescott SL, Bjorksten B. Probiotics for the prevention or treatment of allergic diseases. J Allergy Clin Immunol. 2007;120(2):255-62.
Rautava S, Kalliomaki M, Isolauri E. Probiotics during pregnancy and breast-feeding might confer immunomodulatory protection against atopic disease in the infant. J Allergy Clin Immunol. 2002;109(1):119-121.
Schmitt J, Schakel K, Schmitt N, Meurer M. Systemic treatment of severe atopic eczema: a systematic review. Acta Derm Venereol. 2007;87(2):100-11.
Schram ME, Tedja AM, Spijker R, Bos JD, Williams HC, Spuls PI. Is there a rural/urban gradient in the prevalence of eczema? A systemic review. Br J Dermatol. 2010;162(5):964-73.
Schulz P, Bunselmeyer B, Brautigam M, Luger TA. Pimecrolimus cream 1% is effective in asteatotic eczema: results of a randomized, double-blind, vehicle-controlled study in 40 patients. J Eur Acad Dermatol Venereol. 2007;21(1):90-4.
Sezer E, Etikan I. Local narrowband UVB phototherapy vs. local PUVA in the treatment of chronic hand eczema. Photodermatol PhotoimmunolPhotomed. 2007;23(1):10-4.
Simopoulos AP. Evolutionary aspects of diet, the omega-6/omega-3 ratio and genetic variation: nutritional implications for chronic diseases. Biomed Pharmacother. 2006;60(9):502-7.
Vlaski E, Stavric K, Isjanovska R, Seckova L, Kimovska M. Overweight hypothesis in asthma and eczema in young adolescents. Allergol Immunopathol (Madr). 2006;34(5):199-205.
Williams HC. Established corticosteroid creams should be applied only once daily in patients with atopic eczema. BMJ. 2007;334(7606):1272.
Williams HC, Grindlay DJ. What's new in atopic eczema? An analysis of the clinical significance of systematic reviews on atopic eczema published in 2006 and 2007. Clin Exp Dermatol. 2008 Nov;33(6):685-8. Review.
Wisniewski J, Nowak-Wegrzyn A, Steenburgh-Thanik E, Sampson H, Li X. Efficacy and Safety of Traditional Chinese Medicine for Treatment of Atopic Dermatitis (AD). J Allergy Clin Immunol. 2009 Feb;123(2):S37.
Worm M, Henz BM. Novel unconventional therapeutic approaches to atopic eczema. Dermatology. 2000;201(3):191-195.

Alternative Names

Atopic dermatitis; Dermatitis - atopic; Skin disorders - eczema

Version Info

  • Last Reviewed on 09/10/2011
  • Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.

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