PDE4A and psoriatic arthritis: (((((apremilast) OR (phosphodiesterase 4 inhibitor)) OR (PDE4 inhibitor)) OR (PDE-4 inhibitor)) OR (CC-10004)) AND (((((((((arthritis, psoriatic[MeSH Terms]) OR (arthritic psoriasis[MeSH Terms])) OR (psoriatic arthritis[MeSH Terms])) OR (psoriasis, arthritis[MeSH Terms])) OR (psoriasis arthropathica[MeSH Terms])) OR (psoriasis arthropathy[MeSH Terms])) OR (arthropathies, psoriatic[MeSH Terms])) OR (arthropathy, psoriatic[MeSH Terms])) OR (psoriatic arthropathies[MeSH Terms])) Filter: Randomized Control Trials