Mortality of bullous pemphigoid in Singapore: risk factors and causes of death in 359 patients seen at the National Skin Centre

Abstract

SummaryBackground Bullous pemphigoid (BP) is the most common autoimmune-mediated subepidermal blistering skin disease and is associated with significant morbidity and mortality. Objectives To determine the 3-year mortality rate, risk factors and causes of death in patients with BP in Singapore, compared with the general population. Methods We conducted a retrospective cohort study of all newly diagnosed patients with BP seen at the National Skin Centre from 1 April 2004 to 31 December 2009. Demographic and clinical data on comorbidities and treatment were recorded. Mortality information was obtained from the National Registry of Diseases. Results In total 359 patients were included in our study. The 1-, 2-, 3-year mortality rates were 26Á7%, 38Á4% and 45Á7%, respectively. The 3-year standardized mortality risk for patients with BP was 2Á74 (95% confidence interval 2Á34-3Á19) times higher than for the age-and sex-matched general population. Parkinson disease, heart failure and chronic renal disease were associated with increased mortality, while combination treatment with low-to-moderate-dose corticosteroids and immunomodulatory agents such as doxycycline and/or nicotinamide was associated with lower mortality. Overall, infections were the most common cause of death (59Á8%), with the main causes of death being pneumonia (42Á7%), cardiovascular disease (14Á6%) and stroke (11Á6%). Conclusions This study confirms an increased 3-year mortality rate for patients with BP in Singapore. Risk factors for increased mortality include medical comorbidities, especially neurological, cardiac and renal diseases. Treatment with combination therapy, including the use of low-to-moderate-dose corticosteroid, appeared to decrease mortality risk in patients with BP.

Mortality of patients with bullous pemphigoid in Korea

“…The most recent study on patients from Singapore reported a higher mortality rate (26.7%) than our study; however, the median age of their study population was slightly older (75.7 years) than ours (73 years). 21 A summary of 1-year mortality rate in BP cohorts from recently published studies is shown in Table V. This study was designed to assess the overall survival of patients with BP.…”

“…For all age groups, the rate of observed deaths was higher than that expected for the general population, particularly in BP patients who were 60 to 80 years of age. Several cohort studies have reported that patients with BP have increased mortality, compared with ageadjusted general populations, 17,[19][20][21][22] with the exception of 1 study conducted in the United States, 15 which showed that the morality rate of patients with BP was not higher than that of the general population. Because the US study was a retrospective cohort study, the study might have selection bias.…”

“…13,[15][16][17][18][19][21][22][23] However, some of the data from these studies are based on 1-year mortality rate and others are based on overall mortality. Therefore, we analyzed prognostic factors associated with both 1-year and overall survival.…”

Autoimmune blistering diseases in females: a review

“…The reason for this age-specific trend in sex difference is unexplained. Although the female sex has been associated with a slightly increased incidence of BP, studies have not discovered the female sex to be associated with mortality rate or relapse rates of BP (Cai et al, 2014, Fichel et al, 2014). Future research regarding age-specific sex predominance of BP, as well as its epidemiology in America, Africa, and Oceania, may be implicated.…”

Prognostic factors for mortality in patients with bullous pemphigoid: a meta-analysis

“…Previous studies reported an incidence of BP ranging from 2.5 to 42.8 cases per million per year [2, 11, 14, 23]. BP has been reported to be significantly associated with mortality, with morality rates ranging from 6 to 41% within the first year after diagnosis [1, 3–6, 12, 15, 22, 27, 29, 30, 32]. BP patients also have increased mortality compared with their age and sex-matched controls in the general population [2–4, 12, 14].…”