An Exploratory Trial Investigating the Neurogenic Component in Psoriasis Vulgaris by Use of Botulinum Toxin A

Inclusion Criteria: * Age 18 years or above * A diagnosis of psoriasis vulgaris with lesions located on arms and/or legs and/or trunk * Chronic stable psoriasis vulgaris diagnosed more than 6 months prior to screening. * Women must use a reliable contraceptive during the trial. Exclusion Criteria: * Pregnant or breast feeding women, or women planning to become pregnant. * Skin infection at injection sites * Use of biological therapies or small molecules (marketed or not marketed) with a possible effect on psoriasis vulgaris * Use of systemic treatments with a potential effect on psoriasis vulgaris * Exposure to phototherapy within 4 weeks for PUVA and 2 weeks for UVB prior to Randomisation * Use of potent or very potent (WHO group III-IV) corticosteroids for topical treatment of psoriasis within a 4 week period prior to randomisation * Use of muscle relaxants * History of dysphagia or aspiration * Current diagnosis of guttate, erythrodermic, exfoliative or pustular psoriasis