028 Psychiatric and neurological disorders are associated with bullous pemphigoid – nationwide Finnish Care Register study

Bullous pemphigoid (BP) is an autoimmune blistering skin disease of the elderly with increasing incidence. BP has been shown to be associated with neurological disorders. So far, it has not been exactly established, for example, what subtypes of dementia and stroke are associated with BP, and what is the temporal relation between these diseases. Also, the association between BP and psychiatric disorders has remained controversial in previous studies. To answer these questions, we conducted a retrospective nationwide study using the statutory Finnish Care Register diagnoses between 1987 and 2013. The study population of 4524 BP patients were compared with 66138 patients with basocellular carcinoma (BCC), neurological as well as psychiatric comorbid disorders were evaluated for both groups, and association was estimated by Cox regression analysis and logistic regression analysis. The strongest risk of developing BP was found after diagnosis of multiple sclerosis (MS) (OR=5.8, 95% CI 3.9-8.5) and dementias including other or unspecified dementia (3.8, 95% CI 3.4-4.4), vascular dementia (3.6, 95% CI 2.8-4.5), as well as Alzheimer’s disease (OR= 2.6, 95% CI 2.3-3.0). Among psychiatric diseases, the corresponding risk was strongest in schizophrenia (OR=2.6, 95% CI 2.0-3.5), schizotypal and delusional disorders (OR=2.1, 95% CI 1.6-2.6), and as a novel finding, also personality disorders (OR=2.2, 95% CI 1.3-3.3) preceded BP. In conclusion, many psychiatric disorders, especially schizophrenia, other psychoses, and personality disorders preceded BP. Furthermore, several neurological diseases which cause central nervous system degeneration or inflammation were related to BP, and the association was strongest between MS and BP.