Overview
Bullous pemphigoid is an autoimmune skin condition that occurs mostly in older people (60 years or older). The condition is characterised by painful itching and blisters. The disease is challenging to treat because it can take months to diagnose and years to resolve. The cause behind it is unclear, but previous studies implicated commonly prescribed medicines/vaccines such as gliptins, antibiotics, diuretics, and influenza vaccine. However, most associations between drugs and bullous pemphigoid were found based on data from small specialist hospitals or case reports. Therefore, precise information on drugs and vaccines associated with the condition is needed to help identify the culprit drugs before severe symptoms develop or find drugs associated with a low risk of bullous pemphigoid.
The aim of this project was to examine whether drugs commonly prescribed in older people are associated with increased BP risk using routinely collected electronic healthcare records from UK primary care between 1998 and 2021.
Key facts
1. Why do the research?
The study will help raise awareness about drugs associated with increased risk of bullous pemphigoid. Identifying the condition before it develops into a severe form is crucial, as it can take years to resolve. Conversely, identifying drugs associated with a lower risk of bullous pemphigoid will offer potential treatment alternatives which could prevent this disease altogether.
2. How was the research conducted?
We performed a retrospective, population based, nested case-control study. We used routinely collected health records from UK general practices which contributed to the Clinical Practice Research Datalink (CPRD) between 1998 and 2021 to identify people diagnosed with bullous pemphigoid and matched controls by age, sex, and general practice. We used latest prescription data within 1-year before the diagnosis to determine the exposure to drugs. We accounted for multiple exposure when estimating the association between drugs and bullous pemphigoid. We also addressed biases in our estimates by performing a series of clinically informed sensitivity analyses.
3. What do the results mean for patients?
The knowledge about drugs associated with increased risk of bullous pemphigoid will help patients identify its initial symptoms and raise the issue with their GP earlier. Previously unknown association between drugs and bullous pemphigoid will further contribute to early treatment and perhaps prevention of severe disease.
Who funded the study?
This work was supported by the National Institute for Health and Care Research grant via the Research for Patient Benefit Programme (award ID: NIHR202781).