The relationship between neurological disease and bullous pemphigoid: a population-based case-control study.

Previous small studies and case reports have suggested that neurological disorders may be associated with bullous pemphigoid (BP). The objective of this study was to assess BP risk in patients with neurological diseases. Computerized medical records from the Health Improvement Network, a large population-based UK general practice database, were used to conduct a matched case-control analysis. Conditional logistic regression was used to calculate odds ratios for specified neurological disorders. Comparing cases (n=868) to controls (n=3,453), stroke was seen in 8 vs. 5%, odds ratio (OR) 1.8 (1.3-2.5); dementia in 7 vs. 2%, OR 3.4 (2.4-4.8); Parkinson's disease in 3 vs. 1%, OR 3.0 (1.8-5.0); epilepsy in 2 vs. 1%, OR 1.7 (1.0-3.0); and multiple sclerosis in 1 vs 0.1% (OR 10.7 (2.8-40.2). Estimates were not altered greatly when diagnoses up to 3 years before BP were excluded, except the association with epilepsy was no longer significant. Significant associations were only observed where neurological disease was diagnosed before the onset of pemphigoid. Study findings, except the association with epilepsy, were robust to sensitivity analysis. Strong associations were observed between specific neurological diseases and the later development of BP, supporting possible causal associations. Mechanisms for disease occurrence based on these findings include immobility or age-related autoimmunity.