Bullous pemphigoid and pemphigus vulgaris—incidence and mortality in the UK: population based cohort studyBMJ 2008; 337 doi: https://doi.org/10.1136/bmj.a180 (Published 09 July 2008) Cite this as: BMJ 2008;337:a180
- S M Langan, research fellow1,
- L Smeeth, professor of clinical epidemiology2,
- R Hubbard, professor of respiratory epidemiology3,
- K M Fleming, research associate3,
- C J P Smith, senior research fellow3,
- J West, clinician scientist3
- 1Centre of Evidence-based Dermatology, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH
- 2Department of Epidemiology and Population Health, Centre for Population Studies, Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London
- 3Division of Epidemiology and Public Health, University of Nottingham
- Correspondence to: S Langan
- Accepted 7 May 2008
Objective To determine the incidence of and mortality from bullous pemphigoid and pemphigus vulgaris in the United Kingdom.
Design Retrospective historical cohort study.
Setting Computerised medical records from the health improvement network, a large population based UK general practice database.
Participants Patients with pemphigus vulgaris and bullous pemphigoid diagnostic codes and age, sex, and practice matched controls.
Main outcome measures Incidence and mortality compared with the control population by calendar period, age group, sex, geographical region, and degree of social deprivation.
Results 869 people with bullous pemphigoid and 138 people with pemphigus vulgaris were identified. The median age at presentation for bullous pemphigoid was 80 (range 23-102) years, and 534 (61%) patients were female. The median age at presentation for pemphigus vulgaris was 71 (21-102) years, and 91 (66%) patients were female. Incidences of bullous pemphigoid and pemphigus vulgaris were 4.3 (95% confidence interval 4.0 to 4.6) and 0.7 (0.6 to 0.8) per 100 000 person years. The incidence of bullous pemphigoid increased over time; the average yearly increase was 17% (incidence rate ratio=1.2, 95% confidence interval 1.1 to 1.2). An average yearly increase in incidence of pemphigus vulgaris of 11% (incidence rate ratio=1.1, 1.0 to 1.2) occurred. The risk of death for patients with bullous pemphigoid was twice as great as for controls (adjusted hazard ratio=2.3, 95% confidence interval 2.0 to 2.7). For pemphigus vulgaris, the risk of death was three times greater than for controls (adjusted hazard ratio=3.3, 2.2 to 5.2).
Conclusions Incidences of bullous pemphigoid and pemphigus vulgaris are increasing. The reasons for the changes in incidence are not clearly understood but have implications for identifying causative factors. Both disorders are associated with a high risk of death. Previous estimates may have underestimated the risk of death associated with these diseases.
Contributors: SML, RH, LS, and JW were involved in the conception of the research question, planning the study, and applying for ethical approval. RH, LS, and JW were supervisors of the initial study, which was completed by SML as part of an MSc project at the London School of Hygiene and Tropical Medicine. CJPS extracted the data from the health improvement network database and assisted with data management and guidance on the use of the database. Further data management was by SML, KMF, and JW. SML, KMF, and JW were involved in analysing the data, KMF and JW in a teaching and supervisory capacity. SML drafted the manuscript, which was reviewed by all authors. SML is the guarantor.
Funding: SML is funded by a grant from the BUPA Foundation. LS is supported by a Wellcome Trust senior research fellowship in clinical science. JW is supported by a Department of Health clinician scientist fellowship, and KMF is also funded from that fellowship.
Competing interests: None declared.
Ethical approval: Nottingham research ethics committee.
Provenance and peer review: Not commissioned; externally peer reviewed.