PDE4A and psoriasis: Phosphodiesterase 4 (PDE4) inhibitors are new candidates for psoriasis therapy.<h4>Objectives</h4>To evaluate the efficacy and safety of PDE4 inhibitors in psoriasis.<h4>Method</h4>Randomized clinical trials with PDE4 inhibitors vs placebos in patients with psoriasis were identified from MEDLINE, Embase, Cochrane Controlled Register of Trials, ClinicalTrials.gov, from inception to July 14, 2022.