Bullous pemphigoid (BP) is a serious autoimmune blistering disease that primarily affects older adults. Polypharmacy commonly occurs in this population, but the effect of specific drug combinations on BP risk remains unclear. A nested case-control study in the British Journal of Dermatology analyzed UK Clinical Practice Research Datalink records from 1998 to 2021 to examine this association.

The study analyzed 16,844 BP cases and 79,493 matched controls. Association rule mining (ARM) identified drug combinations more frequently prescribed before BP diagnosis. Cardiovascular and antihypertensive drug pairs produced the strongest signals. Combinations that showed higher lift in cases included ACE inhibitors (ACEIs) with statins (fold change [FC] 1.31), antiplatelets with statins (1.23), proton pump inhibitors (PPIs) with antiplatelets (1.22), PPIs with statins (1.22), and ACEIs with antiplatelets (1.20). At the substance level, simvastatin-ramipril (1.30), aspirin-simvastatin (1.21), aspirin-ramipril (1.19), and aspirin-bendroflumethiazide (1.16) showed the strongest associations. Sensitivity analyses using a 30-day co-prescription window confirmed similar results.

The study concluded that cardiovascular drug combinations most frequently increased BP risk. Risk after combinations appeared lower than risk after single drugs. The findings suggest that physicians should monitor for new skin changes in older adults receiving these therapies, but should not discontinue essential treatments.