Comparison of Skin Thickness Under Treatment With Pimecrolimus 1% Cream, Hydrocortisonacetat 1% Cream, Betamethasonvalerat 0,1% Cream and Clobetasol-17-propionat 0,05% Cream Assessed by Optical Coherence Tomography (OCT) and 20-MHZ Ultrasound

Inclusion Criteria: * male and female probands age between 18-40 years * skin healthy * skintype I-III according to Fitzpatrick Exclusion Criteria: * women of childbearing potential without adequate contraception * pregnant or breastfeeding * genetic defect of epidermal barrier * external or systemic treatment with drugs, which probably have an effect to the thickness of skin or to the production of teleangiektasien within the last 6 month before study entry * skin disease, which hinder the evaluation with OCT, ultrasound or dermaphot * UV treatment within the last 4 weeks before study entry * participation to another clinical trial within the last 30 days before study entry * allergy against pimecrolimus or hydrocortison or betamethasonvalerat or Clobetasol-17-propionat * severe systemic diseases; ongoing immunosuppressive treatment * planned vaccination should realize before study entry or 28 days after end of treatment