Associations among bullous pemphigoid and various neurological diseases: A systematic review and meta-analysis

Bullous pemphigoid is a common autoimmune bullous skin disease of the elderly. The objective of this meta-analysis was to assess the association of bullous pemphigoid with neurological disease. We conducted a systematic search of three databases, screening for articles with relevant search terms from database inception until August 01, 2020. The Newcastle-Ottawa quality assessment scale was used to evaluate the quality of the retained articles. Random effects models were applied to calculate the pooled odds ratio and confidence intervals. Publication bias was evaluated by funnel plot and Egger's test. A total of 25 studies with 44,726 BP patients were included in this meta-analysis. Patients with BP were significantly more likely to have any neurological disease [odds ratio (OR): 4.5, 95% confidence interval (CI): 3.2-6.5]. This was true for: stroke (OR: 2.7, 95% CI: 2.2-3.4), Parkinson's disease (OR: 2.7, 95% CI: 2.2-3.2), dementia (OR: 4.1, 95% CI: 3.0-5.7), Alzheimer's disease (OR: 2.3, 95% CI: 1.2-4.4), epilepsy (OR: 2.4, 95% CI: 1.6-3.5), and multiple sclerosis (OR: 3.3, 95% CI: 2.1-5.2), compared to controls. Bullous pemphigoid patients have an increased prevalence of neurological disease. Clinicians should be aware of this increased prevalence, its possible implications, and preventive measures for patients.