Arthritis, PsoriaticPsoriasisArthritisArthritis, RheumatoidArthritis, ExperimentalAntirheumatic AgentsDermatologic AgentsArthritis, InfectiousSpondylitis, AnkylosingJointsArthritis, JuvenileNail DiseasesArthritis, ReactiveSynovial MembraneSynovial FluidSeverity of Illness IndexHand JointsHLA-C AntigensRheumatic DiseasesSpondylitisReceptors, Tumor Necrosis FactorSynovitisSpondylarthropathiesToe JointTumor Necrosis Factor-alphaMethotrexateRheumatoid FactorSpondylarthritisAntibodies, MonoclonalArthrographyFinger JointFoot JointsPeriostitisImmunoglobulin GBlood SedimentationOsteoarthritisAntibodies, Monoclonal, HumanizedPUVA TherapyTreatment OutcomeUltraviolet TherapySkinGenetic Predisposition to DiseaseSacroiliac JointHLA-B27 AntigenRheumatologyIritisAnti-Inflammatory AgentsEtretinateCornified Envelope Proline-Rich ProteinsDouble-Blind MethodBiological ProductsCase-Control StudiesImmunosuppressive AgentsImmunologic FactorsAge of OnsetNailsBiological MarkersAnti-Inflammatory Agents, Non-SteroidalCoal TarDisability EvaluationKnee Joint