Oral Manifestations of Psoriasis: A Comprehensive Review of the Literature

Psoriasis is a chronic immune-mediated inflammatory disorder increasingly recognized as a systemic disease, yet the clinical significance and underlying mechanisms of its oral manifestations remain incompletely understood. Building on previous reviews, this narrative review provides an updated synthesis of the clinical spectrum and pathogenic mechanisms of oral involvement in psoriasis, with particular emphasis on the specificity and strength of reported associations, conflicting evidence, pediatric presentations, and differential diagnosis. The relevant literature was identified through searches of PubMed, Scopus, and Web of Science. Geographic tongue and fissured tongue are the most consistently reported oral findings, whereas geographic stomatitis, palatal involvement, and psoriatic cheilitis are less common. Histopathological, immunological, and genetic findings suggest overlapping mechanisms between cutaneous psoriasis and selected oral conditions, particularly involving IL-17/IL-23-related inflammatory pathways; however, most oral findings are not specific to psoriasis. Evidence supports an association with poorer periodontal health, whereas the relationship with oral malignancy remains inconsistent. Particular attention is given to pediatric oral involvement, differential diagnosis, and areas in which observational or case-based evidence limits clinical interpretation. Oral lesions should therefore be interpreted within the broader clinical context and alternative inflammatory, infectious, traumatic, and nutritional causes considered. Further prospective and longitudinal studies are needed to clarify the diagnostic, prognostic, and therapeutic significance of oral findings in psoriasis.