The Role of Accessible Hematological Markers in Bullous Pemphigoid: A Systematic Review

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease. In recent decades, an increasing incidence of BP has been reported. The rationale for this study arises from the limited availability of advanced immunopathological and serological assays for assessing disease activity in bullous pemphigoid across many clinical centers. This systematic review evaluates evidence regarding hematological markers derived from complete blood count (CBC), such as eosinophil count and neutrophil-to-lymphocyte ratio (NLR), in BP patients. The Ovid MEDLINE and EMBASE databases were searched for English-language peer-reviewed papers published until 2 May 2025. Sixteen studies involving 1775 patients were included. Eosinophil count consistently correlated with disease severity, clinical phenotype, treatment response, and relapse risk, while NLR showed potential as a prognostic and therapeutic marker. Given their accessibility and cost-effectiveness, these parameters may have practical value in the routine clinical management of BP.