AbstractBackgroundThe pathogenesis of livedoid vasculopathy (LV) remains unknown. Although platelet activation occurs in LV, little research has been conducted on LV platelet morphology parameters. The purpose of this study was to investigate whether platelet morphology changes in LV and its clinical significance.MethodsTwenty‐seven LV patients and 21 cutaneous small vessel vasculitis (CSVV) patients, all at the active stage, were included. Platelet parameters in active‐ and stable‐stage LV and CSVV patients were compared. Correlations between these platelet parameters and LV composite clinical scores were analysed.ResultsLV patients' mean age was 25.48 years (range: 9–62 years), and 81.48% (22/27) were women and 18.52% (5/27) were men. The platelet counts and plateletcrit (PCT) levels were significantly elevated in LV patients compared with CSVV patients and in active‐stage LV patients compared with stable‐stage LV patients after treatment. LV patient composite clinical scores that reflected disease severity and activity were positively correlated with the platelet count and PCT levels.ConclusionAltered platelet morphology was detected in LV patients. Platelet count and PCT might be haematological biomarkers for early prediction of LV activity and relapses and for differential identification between LV and CSVV.