PsoriasisPUVA TherapyUltraviolet TherapyDermatologic AgentsAcitretinKeratolytic AgentsArthritis, PsoriaticSeverity of Illness IndexAntibodies, Monoclonal, HumanizedAntibodies, MonoclonalCoal TarHLA-C AntigensCohort StudiesSkinAnthralinTreatment OutcomeCardiovascular DiseasesGreat BritainKeratinocytesRisk FactorsNail DiseasesClobetasol