The purpose of this study is to determine the effect of topical pimecrolimus on the immune system by assessing the levels of antimicrobial peptides in the skin of patients with eczema. It is hypothesized that pimecrolimus applied topically will repair the body's immune system in patients with eczema by increasing antimicrobial peptides.

Patients with atopic dermatitis (AD) have higher rates of skin infections from viruses and bacteria. They also have an impaired innate immune system. Antimicrobial peptides are a component of the innate immune system which are decreased in atopics. In vitro, pimecrolimus has demonstrated its ability to increase antimicrobial peptides. This study will examine the ability of pimecrolimus to increase antimicrobial peptides in vivo in AD patients. Thus, the study will yield a better understanding of the role of pimecrolimus in regulating the immune system in atopics.

Inclusion Criteria:

1. Age 18-70 years
2. Target lesion IGA ≥2
3. Target IGA=0 (for non-lesional site)
4. Male or female of any race and ethnicity
5. Chronic AD for more than one year duration
6. Subject of child-bearing potential must be willing to practice effective birth control during the study
7. Subject agrees to comply with study requirements and attend all required visits.

Exclusion Criteria:

1. Patients ≥ 18 years of age with only AD of the face
2. Women of childbearing potential not using the contraception method(s) specified in this study (abstinence, IUD, diaphragm, oral contraceptives)
3. Patients with severe medical condition(s) that in the view of the investigator prohibits participation in the study
4. Hypersensitivity to pimecrolimus cream or any excipient of the cream
5. Subject has a skin disorder in addition to dermatitis in the areas to be treated
6. Subject has Netherton's syndrome or other genodermatoses that result in a defective epidermal barrier
7. Pregnant or nursing females
8. Immunocompromised patient (e.g., lymphoma, HIV/AIDS, Wiskott-Aldrich Syndrome), or with a history of active or malignant disease (excluding non-melanoma skin cancer)
9. History of psychiatric disease or history of alcohol or drug abuse that would interfere with the ability to comply with the study protocol
10. Patients known to be non-compliant with a medication regimen
11. Subjects with significant concurrent medical condition(s) at screening that in the view of the investigator prohibits participation in the study (e.g., severe concurrent allergic disease, condition associated with malignancy, and condition associated with immunosuppression)
12. Active viral or fungal skin infections at the target areas
13. Previous participation in this study
14. Ongoing participation in another investigational trial
15. Use of any oral or topical antibiotic during the study and up to one week prior to entering the study
16. Use of any local therapy for AD less than one week prior to screening
17. Use of any systemic immunosuppressive therapy for AD less than four weeks prior to screening.