Blank-MN, blank layered MNs; C6, coumarin 6; CLSM, confocal laser scanning microscope; DIC, diclofenac sodium; DIC-MN, layered MNs loading DIC in the tip-layer of needles; Diclofenac sodium; HA, hyaluronic acid; IL-17A, interleukin 17A; IMQ, imiquimod; IVISR, in vivo imaging system; Layered microneedles; MIX-MN, unlayered MNs loading the mixture of DIC and TAC in needles; MN, microneedle; NIC, nicotinamide; NSAIDs, nonsteroidal anti-inflammatory drugs; Need-based drug delivery; OCT, optical coherence tomography; PASI, psoriasis area and severity index; PDMS, polydimethylsiloxane; PVP, polyvinyl pyrrolidone; PsA, psoriatic arthritis; Psoriasis; Psoriatic arthritis; RhB, rhodamine B; SC, stratum corneum; SEM, scanning electron microscope; TAC, tacrolimus; TAC-MN, layered MNs loading TAC in the inter-layer of needles; TD-MN, layered MNs co-loading TAC in the inter-layer of needles and DIC in the tip-layer; TEWL, transepidermal water loss; TNF-α, tumor necrosis factor α; Tacrolimus