The purpose of the study is to compare the anti-psoriatic effect of marketed products with Daivobet® ointment in a plaque test

Inclusion Criteria: (in summary)

• Subjects having understood and signed an informed consent form
• All skin types
• Subjects with a diagnosis of psoriasis vulgaris with lesions located on arms, legs or trunk. The lesions must have a total size suitable for application. The subjects should be asked if their lesions have been stable
• Subjects willing and able to follow all the study procedures and complete the whole study
• Subjects affiliated to social security system

Exclusion Criteria: (in summary)

• Females who are pregnant, of child-bearing potential and who wish to become pregnant during the study, or who are breast feeding
• Subjects using biological therapies (marketed or not marketed) with a possible effect on psoriasis (e.g. alefacept, efalizumab, etanercept, infliximab, adalimumab) within 12 weeks prior to study drug administration
• Systemic treatments with all other therapies than biologicals, with a potential effect on psoriasis vulgaris (e.g., corticosteroids, vitamin D-analogues, retinoids, immunosuppressants) within the 4-week period prior to randomisation
• Subjects using one of the following topical drugs for the treatment of psoriasis within four (4) weeks prior to study drug administration: - Potent or very potent (WHO group III-IV) corticosteroids - PUVA or Grenz ray therapy
• Subjects using one of the following topical drugs for the treatment of psoriasis within two (2) weeks prior to study drug administration: - WHO group I-II corticosteroids - Topical retinoids - Vitamin D-analogues - Topical immunomodulators (e.g. macrolides) - Anthracen derivatives - Tar - Salicylic acid - UVB therapy
• Subjects with skin manifestations in relation to syphilis or tuberculosis, rosacea, perioral dermatitis, acne vulgaris, atrophic skin, striae atrophicae, fragility of skin veins, ichthyosis, acne rosacea, ulcers and wounds within the plaque test areas