Dermatitis Herpetiformis and Celiac Disease Increase the Risk of Bullous Pemphigoid.

Bullous pemphigoid (BP) and dermatitis herpetiformis (DH) are autoimmune bullous skin diseases. DH has been described to evolve into BP and the two diseases can have overlapping clinical appearances and diagnostic findings, but the association between DH and BP has not previously been studied in a large population. To evaluate DH and celiac disease as risk factors for BP, we conducted a retrospective case-control study of patients with BP and matched controls with basal cell carcinoma diagnosed in Finland between 1997 and 2013. A total of 3,397 patients with BP and 12,941 controls were included in the study. Forty-one (1.2%) BP patients and 7 (0.1%) controls had preceding DH. Diagnosed DH increased the risk of BP 22-fold (odds ratio = 22.30; 95% confidence interval = 9.99-49.70) and celiac disease 2-fold (odds ratio = 2.54; 95% confidence interval = 1.64-3.92) compared to controls. Eighteen (43.9%) of the patients who had DH and subsequent BP had bought dapsone during the 2 years prior to their BP diagnosis. Mean time between diagnosed DH and BP was 3 years. We conclude that diagnosis of DH is associated with a striking increase in the risk for BP.

Oral diabetes medications other than dipeptidyl peptidase 4 inhibitors are not associated with bullous pemphigoid: A Finnish nationwide case-control study.

BACKGROUND: Dipeptidyl peptidase 4 inhibitors (DPP4is) used to treat diabetes have been reported to be associated with an increased risk of bullous pemphigoid (BP). There are no previous reports analyzing the risk of BP in patients who are using other diabetes medications. OBJECTIVE: To evaluate the association between diabetes medications other than DPP4i and development of BP. METHODS: We investigated the prevalence of diabetes among patients with BP and the association between the use of diabetes drugs (excluding DPP4i, metformin, and insulin) and BP by analyzing national Finnish registry data for 3397 patients with BP and 12,941 patients with basal cell carcinoma as controls. RESULTS: Our results show that 19.6% of patients with BP have type 2 diabetes. Use of none of the investigated medications was associated with an increased risk of BP. LIMITATIONS: Because this was a registry-based study, it was not possible to verify the accuracy of the diagnoses. The risk of BP in users of glucagon-like peptide 1 receptor agonists could not be analyzed. CONCLUSION: Our study shows that the investigated diabetes drugs are not associated with an increased risk of BP in a Finnish patient database, indicating they can be safely used in this population. Generalization of these results to other populations will require further study.

Psychiatric and neurological disorders are associated with bullous pemphigoid - a nationwide Finnish Care Register study.

Bullous pemphigoid (BP) is an autoimmune blistering skin disease with increasing incidence. BP is associated with neurological disorders, but it has not been established, 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 is controversial. We conducted a retrospective nationwide study, using the Finnish Care Register for Health Care diagnoses between 1987 and 2013. The study population of 4524 BP patients were compared with 66138 patients with basocellular carcinoma (BCC), neurological and psychiatric comorbid disorders were evaluated for both groups, and associations were estimated by Cox regression and logistic regression analyses. The strongest risk of developing BP was found after diagnosis of multiple sclerosis (MS) (OR=5.9, 95% CI 3.9-8.5). Among psychiatric diseases, the corresponding risk was strongest in schizophrenia (OR=2.7, 95% CI 2.0-3.5), 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, carry heightened risk for BP. Furthermore, several neurological diseases which cause central nervous system inflammation or degeneration were related to BP, and the association was strongest between MS and BP.

Risk of Death in Bullous Pemphigoid: A Retrospective Database Study in Finland.

Bullous pemphigoid (BP) is an autoimmune skin disease of elderly people, which is associated with increased mortality. The aim of this study was to investigate the standardized mortality ratio (SMR) for BP in Finland, and concomitant comorbidities and medications. This was a retrospective database study of all cases of BP diagnosed at the Department of Dermatology, Oulu University Hospital, Finland, between 1985 and 2012. A total of 198 immunologically confirmed cases of BP were found. One-year mortality was 16.7%, and SMR 7.56 (95% confidence interval (CI) 4.98-10.14). The most common comorbidities were cardiovascular diseases (76.3%) and neurodegenerative diseases (40.9%). Malignancies (8.6%) were associated with increased mortality (hazard ratio = 2.4, 95% CI 1.1-5.5, p = 0.047). A novel finding was that polypharmacy was very common in patients with BP, and the higher the number of drugs, the greater the mortality. In conclusion, the mortality for BP in Finland is 7.6-fold that of a reference population, and malignancies and polypharmacy are associated with increased mortality.