Shared Inflammatory Mechanisms in Psoriasis and Periodontitis: A Cross‐Sectional Study

Background Psoriasis and periodontitis are chronic inflammatory diseases fueled by immune dysregulation. This study investigated their association by evaluating periodontal parameters and tumor necrosis factor‐alpha (TNF‐α), interleukin‐17A (IL‐17A), and YKL‐40 levels in gingival crevicular fluid (GCF) and serum. Methods Sixty individuals were assigned into three groups: healthy controls (C), periodontitis (P), and psoriasis with periodontitis (PS + P). Periodontal indices, including plaque index (PI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL), were recorded. TNF‐α, IL‐17A, and YKL‐40 concentrations in GCF and serum were analyzed using enzyme‐linked immunosorbent assay (ELISA). Results Periodontal parameters were markedly higher in both periodontitis groups than in controls ( p < 0.05). Serum TNF‐α and IL‐17A levels were highest in the PS + P group. GCF TNF‐α was increased in both P and PS + P groups, while GCF IL‐17A was elevated only in the P group. GCF and serum YKL‐40 were elevated in both periodontitis groups, without a significant intergroup difference. GCF TNF‐α correlated with PD ( p < 0.001), CAL ( p < 0.001) and PI ( p < 0.001), while GCF YKL‐40 correlated with CAL ( p < 0.001) and BOP ( p < 0.001). In the PS + P group, GCF YKL‐40 also correlated with GCF TNF‐α ( p = 0.001) and IL‐17A ( p = 0.003). Conclusion These findings suggest a possible influence of psoriasis on periodontal inflammatory responses.