O/E: there was a wide-spread dermatitis on torso and extremities. No frank bullae but there was a suggestion of vesicles. No burrows were seen. Vesicles were noted on the palms and soles.
An eliptical biopsy was done as well as a 3 mm punch biopsy from perilesional skin for DIF.
Histopath showed: Eosinophilic spongiosis and spongiotic vesiculation.
DIF was positive for IgG in a linear pattern at the DEJ
Histological Photographs courtesy of Dr. Jag Bhawan, Boston University SkinPath Laboratory
Diagnosis: Bullous Pemphigoid secondary to DPP-4 inhibitor.
Discussion: DPP-4 inhibitors are a class of drugs that are used for Type 2 diabetes. There have been eight references to BP as a cutaneous drug effect DPP-4 inhibitors in PubMed (the first was in 2016). It is clear that we will be seeing more of these patients what with the wide-spread usage of DPP-4 inhibitors.
Acknowledgement: Special thanks to Rick Sontheimer, M.D. who alerted me to this phenomenon and Dr. Jag Bhawan for the pathology interpretation and the beautiful photomicrographs.
References:
1. Bullous Pemphigoid Associated with the Dipeptidyl
Peptidase-4 Inhibitor Sitagliptin in a Patient with Liver Cirrhosis Complicated
with Rapidly Progressive Hepatocellular Carcinoma. Harada M et. al. Intern
Med. 2017 Sep 15;56(18):2471-2474 Free Ful Text.
2. Dipeptidyl peptidase IV inhibitors, a risk factor for
bullous pemphigoid: Retrospective multicenter case-control study from France
and Switzerland. Benzaquen M, det. Al.. J Am Acad Dermatol. 2018
Jun;78(6):1090-1096
CONCLUSIONS: DPP4is, especially vildagliptin, are associated
with an increased risk for development of BP. Their use needs to be carefully
evaluated, particularly in high-risk patients, such as males and those age 80
years or older. Full Abstract.
3. Vildagliptin significantly increases the risk of bullous
pemphigoid: A Finnish nationwide registry study. O. Varpuluoma et. al. J.
Invest Dermatol:
Volume 138, Issue 5, Supplement, Page S46, 2018. Full Abstract (Supplied by Rick Sontheimer)
