This study was designed to further increase the understanding of the pharmacokinetics of tacrolimus in the affected skin of atopic dermatitis patients following repeated topical application of tacrolimus ointment 0.1%.

The study was conducted on an out-patient basis, with patients self-administering the ointment twice daily at home. However, on Days 1 and 14 there was only a single application of ointment and this was applied by the Investigator or his/her designee in the clinic. An area of the affected skin was selected for skin biopsy of sufficient size for 5 biopsy samples. The biopsy samples were taken from the same lesion(s) if possible or from an adjacent lesion in the same anatomical area at all times. All areas selected for treatment were treated with tacrolimus ointment 0.1% for a period of two weeks with a follow up period of one week. Two pharmacokinetic profiles (Days 1 and 14) and five skin biopsy samples (Days 1, 2, 15, 18 and 21) were taken.

Inclusion Criteria:

• Using the Hanifin and Rajka Criteria, the patient has a diagnosis of moderate to severe atopic dermatitis
• Using the Rajka and Langeland grading system, the patient's atopic dermatitis score is at least 4.5 (moderate to severe)

Exclusion Criteria:

• Patient has a serious skin disorder other than atopic dermatitis.
• Patient has history of eczema herpeticum (defined as an acute disseminated cutaneous herpes simplex type 1 or 2 infection associated with constitutional symptoms like fever, headache, malaise, regional or generalised lymphadenopathy in an individual with eczema).