Clinical Edge

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Psoriasis and Risk of Bullous Pemphigoid

There is an increased risk of bullous pemphigoid (BP) among patients with psoriasis, a new study found, with > one-third of BP cases diagnosed in the first year after incident psoriasis. The nationwide population-based cohort study in Taiwan consisted of 109,777 psoriatic patients and 109,777 matched non-exposed controls. Researchers found:

  • Psoriasis was significantly associated with an increased risk of BP (hazard ratio, 3.05).
  • The mean interval between the diagnoses of psoriasis and BP was 2.86 years, with the highest occurrence in the first year after psoriasis diagnoses, and gradually decreasing with each year of observation.
  • Psoriatic patients with BP were significantly younger than BP patients in the non-exposed group.


Ho YH, Hu HY, Chang YT, et al. Psoriasis is associated with increased risk of bullous pemphigold: A nationwide population-based cohort study in Taiwan. [Published online ahead of print May 7, 2019]. J Dermatol. doi:10.1111/1346-8138.14902.


There are several immune dysregulated disorders that have a higher risk with psoriasis such as psoriatic arthritis and Crohn’s disease. The co-existence of bullous pemphigoid and psoriasis has been reported previously. This study adds another layer of the higher incidence between the 2 conditions. The management of these 2 conditions may present a therapeutic challenge. Previous reports have indicated that TNF-blockers may treat both conditions simultaneously. —Paul S. Yamauchi, MD, PhD; Clinical Assistant Professor of Dermatology David Geffen School of Medicine at UCLA; Harbor-UCLA Medical Center Division of Dermatology; Adjunct Associate Professor John Wayne Cancer Institute.