Evaluation of hematological inflammatory parameters in patients with palmoplantar pustulosis

Background Palmoplantar pustulosis (PPP) is a chronic inflammatory disease of ill‐defined etiopathology. Recent studies have proposed complete blood count‐based hematological parameters, such as neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR), as biomarkers to monitor disease status in many inflammatory diseases. This study aimed to analyze for the first time the clinical significance of hematological parameters, including NLR, monocyte/lymphocyte ratio (MLR), PLR, mean platelet volume (MPV), plateletcrit (PCT), and pan‐immune‐inflammation value (PIV) in PPP patients. Methods We retrospectively investigated the clinical and laboratory data of 237 patients with PPP and 250 sex‐age‐matched healthy controls (HCs). Hematological parameters were compared between patients with PPP and HCs. The correlations between these parameters and disease severity, as well as treatment response, were analyzed. Results NLR, MLR, MPV, PCT, and PIV values were significantly higher in PPP patients than in HCs. But in receiver‐operating characteristic analyses, only monocyte count (Youden Index = 0.53), PCT (Youden Index = 0.65), and PIV (Youden Index = 0.52) performed relatively accurate distinguishment between moderate‐to‐severe cases and mild cases. PCT and PIV values were significantly correlated with disease severity. After treatment, both PIV and PCT values decreased significantly in the responder group but not in the non‐responder group. Conclusions Hematological parameters altered significantly in PPP patients. PCT and PIV can be used as simple and inexpensive biomarkers for systemic inflammation in PPP patients.