Bullous pemphigoid (BP) is the most common autoimmune blistering disorder. Its presentation is polymorphic.
To investigate different clinical and biological profiles of BP.
We conducted a retrospective 2-center study including all BP patients seen between January 1, 2015, and February 28, 2021. We performed hierarchical clustering on principal components.
Three clusters were identified. Patients in cluster 1 (n = 155) were older than those in clusters 2 (n = 89) and 3 (n = 35; P < .0001), more frequently presented pauci-bullous BP (n = 63 [41%] vs 14 [16%] and 2 [6%], respectively; P < .0001) and had anti-BP230 antibodies in 87% of cases. More than 100 blisters were observed in 14 patients (40%) from cluster 3, versus 3 (2%) from cluster 1 and 0 (0%) from cluster 2 (P < .0001). Frequency of mucosal involvement was higher in cluster 3 (n = 32 [91%, including epiglottis in 40%] vs 11 [7%] and 34 [38%]; P < .0001). In clusters 2 and 3, 70% and 74% of patients had antibodies targeting only BP180. Those in cluster 3 received more lines of systemic treatment and experienced more relapses.
Retrospective study without immunoelectron microscopy.
We identified 3 different BP clusters, including one corresponding to severe BP180+ BP230- BP with features common to mucous membrane pemphigoid.

A high level of anti-BP180 antibodies on enzyme-linked immunosorbent assay and a persistent positive direct immunofluorescence at the end of treatment (immunologic tests, [ITs]) are predictors of relapse after treatment cessation (TC) in patients with bullous pemphigoid.
To evaluate the real-life impact of the immunologic-based decision of TC on the 3- and 6-month relapse rates after TC in bullous pemphigoid.
Retrospective multicentric study included patients followed almost 6 months after TC. Patients were classified according to whether the TC decision was in accordance with the results of ITs performed during the 3 months before TC, despite the results of ITs or without ITs performed.
We included 238 patients. Three months after TC, 36 patients showed relapse: 14 of 95 patients with TC in accordance with IT results (14.7%); 5 of 21 with TC despite ITs (23.8%); and 17 of 122 with TC without ITs (13.9%; P = .5). Six months after TC, the relapse rate was 18.9%, 28.6%, and 18.9% (P = .56), respectively, in the 3 groups.
The retrospective design and the limited follow up.
In real-life practice, in bullous pemphigoid, the 3- and 6-month relapse rates were not significantly reduced with TC decision based on results of ITs as compared with a classic clinical-based decision.

BACKGROUND: Many studies have corroborated the association of dipeptidyl peptidase-4 inhibitors (DPP4i) use with bullous pemphigoid (BP). It has been speculated that this drug-induced variant presents with a different clinical spectrum than conventional BP.
OBJECTIVE: To determine the prevalence of DPP4i-induced cases of BP and to evaluate whether gliptin-related BP has specific clinicopathological and immunological features.
METHODS: We conducted a retrospective, observational study of BP cases attended at our centre between January 2000 and June 2020. Epidemiological, clinical, histopathological and laboratory data were collected.
RESULTS: A total of 257 cases of BP were collected; 51 (24.3%) were on treatment with DPP4i. When analysing DPP4i-induced BP cases, generalized BP was the predominant pattern and scalp/mucosal involvement was found in 13 patients. Gliptin-related BP cases were associated to a decrease in the eosinophilic infiltrate (p = 0.000) and both the detection rate and concentration of anti-BP180 IgG were lower (p = 0.004, p = 0.001, respectively) than non-DPP4i cases.
CONCLUSIONS: Retrospective, single-centre study.
CONCLUSIONS: Our large DPP4i-induced BP case series has highlighted that DPP4i-induced BP is characterized by generalized lesions and scalp involvement. Lower titres of anti-BP180 antibodies and a decrease in eosinophils infiltrating into the skin may be distinct features of DPP4i-related BP.