A Psoriasis Plaque Test Trial With LEO 90100 Compared to Betesil® in Patients With Psoriasis Vulgaris

Inclusion Criteria: * Signed and dated informed consent has been obtained * Subjects with a diagnosis of psoriasis vulgaris with preferably three lesions (plaques) located on arms, legs and/or trunk or at least two lesions (plaques) located on arms, legs and/or trunk. For subjects with three lesions, each lesion must have a size suitable to accommodate 2 test sites (test site area 5 cm2, distance between two test sites at least 2 cm). For subjects with two lesions, one lesion must have a size suitable to accommodate 4 test sites, and the other lesion must accommodate 2 test sites. * Age 18 years or above * Outpatients * Female subjects must be of either * non-childbearing potential, i.e. post-menopausal or have a confirmed clinical history of sterility (e.g. the subject is without a uterus or has tubal ligation) or, * child-bearing potential provided there is a confirmed negative pregnancy test prior to trial treatment to rule out pregnancy. Exclusion Criteria: * Female subjects who are breast feeding * Systemic treatment with biological therapies, whether marketed or not, with a possible effect on psoriasis vulgaris within the following time periods prior to randomisation: * Etanercept - within 4 weeks prior to randomisation and during the trial * Adalimumab, infliximab - within 8 weeks prior to randomisation and during the trial * Ustekinumab - within 16 weeks prior to randomisation and during the trial * Other products - within 4 weeks/5 half-lives prior to randomisation and during the trial (whichever is longer) * Systemic treatment with all other therapies than biologicals, with a potential effect on psoriasis vulgaris (e.g., corticosteroids, retinoids, immunosuppressants) within the 4-week period prior to randomisation and during the trial * Subjects using phototherapy within the following time periods prior to randomisation and during the trial: * PUVA: 4 weeks * UVB: 2 weeks * Subjects using one of the following topical drugs for the treatment of psoriasis within the 4 week period prior to randomisation and during the trial: * Potent or very potent (WHO group III-IV) corticosteroids * Subjects using one of the following topical drugs for the treatment of psoriasis within 2 weeks prior to randomisation and during the trial: * WHO group I-II corticosteroids (except if used for treatment of scalp and/or facial psoriasis) * Topical retinoids, Vitamin D analogues, Topical immunomodulators (e.g. calcineurin inhibitors), Tar products, Salicylic acid * Subjects using emollients on the selected plaques within 1 week before randomisation and during the trial * Initiation of, or expected changes to concomitant medication that may affect psoriasis vulgaris (e.g., beta blockers, antimalarial drugs, lithium and ACE inhibitors) within 2 weeks prior to the randomisation and during the trial * Subjects with current diagnosis of guttate, erythrodermic, exfoliative or pustular psoriasis