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Southwestern United States
Information for patients with allergy and related problems
in the Southwest

Eczema and atopic dermatitis

Eczema is a chronic skin rash that is extremely itchy and consists of numerous small pin-head sized bumps (papules) or larger blisters on a background of inflamed, scaly skin.   The papules can progress to vesicles (tiny blisters) and scratching provoked by severe itch often causes bleeding, ulceration and secondary infection in the affected skin.  In contrast to urticaria, each area of skin affected remains unchanged in size over several days.  The skin feels rough, unlike skin affected by urticaria.

Allergic eczema, also known as atopic dermatitis, is a form of eczema.  It is a common condition that usually begins in early childhood, and appears to be a result of abnormal inflammatory processes in the skin that are consistent with or closely resemble allergic inflammation.  Patients with atopic dermatitis often have allergic rhinitis, asthma or food allergies and usually have a strong family history of allergy.  Nevertheless a causative relationship between allergy and atopic dermatitis is not clear.   The rash usually involves both sides of the body symmetrically, and both involved and uninvolved skin tend to be abnormally dry.  When the itch of atopic dermatitis is severe, scratching causes skin damage and entry of bacteria into tissues under the skin, where allergic reactions to bacterial products develop, further aggravating the dermatitis.  This condition usually affects the cheeks and outer aspects of the limbs in infants and in the skin folds of the arms and legs of older children and adults.  It tends to improve with age in childhood, often disappearing in adult life, but severely affected skin can become permanently scarred or depigmented.  The tendency to dry skin usually persists after resolution of inflammation. 

Contact dermatitis is a chronic skin rash caused by contact with a substance to which the patient has become allergic.  The rash is usually confined to the area of contact.  Examples of substances that cause contact dermatitis are poison ivy, nickel, glues used for shoes and latex.  Allergy to latex is a common problem among health professionals and other workers who use latex rubber gloves.  In addition to contact sensitivity it can cause asthma and, in severe cases, anaphylaxis.   Patch testing often identifies the cause of contact dermatitis.

Contact allergy may occur through airborne particles, causing airborne contact dermatitis.  Ragweeds (including triangle-leaf bursage in Arizona) and other plants can cause airborne dermatitis. 

Treatment of atopic dermatitis is dependent mainly on reduction of itching and scratching through moisturizing the skin, reducing inflammation and antihistamine therapy.   Hydration of skin is best achieved by applying greasy creams, oils or ointments after prolonged bathing without soap.  Softened water is not recommended because it facilitates removal of oil from the skin.  Reduction of inflammation requires use of topical anti-inflammatory  preparations.  If hydrocortisone preparations obtainable over the counter in pharmacies do not completely eliminate redness from the affected skin, or if extensive areas are involved, physician consultation and prescription medications are needed to control the problem.  Consultation with an allergist or dermatologist is recommended if the rash persists.  If there are associated problems including asthma, hay fever, suspected food allergies or recurring infections, an allergist/immunologist should be consulted.

Further Reading
AAAAI:   Allergic skin conditions
AAAAI:   Latex allergy

Williams H. Flohr C.
How epidemiology has challenged 3 prevailing concepts about atopic dermatitis. [Review] [38 refs] Journal of Allergy & Clinical Immunology. 118(1):209-13, 2006 Jul.

Akdis CA. Akdis M. Bieber T. et al.  Diagnosis and treatment of atopic dermatitis in children and adults: European Academy of Allergology and Clinical Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL Consensus Report.[Review] [200 refs] Journal o
f Allergy & Clinical Immunology. 118 (1):152-69, 2006 Jul. 


Disclaimer:   This site is for educational purposes only.  Any information that you have found in this web site is not intended to replace medical care or advice given to you by your own physicians. You should consider consulting your local medical library and other web sites for additional information. 

Comments and suggestions welcome!   Email: schumach@u.arizona.edu
Content Owner:  Michael J. Schumacher, MB, FRACP, The University of Arizona

Updated 1/2012