Non-Bullous Pemphigoid: A Single-Center Retrospective Study

Introduction: Bullous pemphigoid (BP) is an autoimmune disease that typically presents with blisters, but sometimes early lesions may be eczematous, maculopapular, or urticarial. The aim of the present study was to highlight possible differences between typical bullous and non-bullous pemphigoid (NBP) and compare results with the literature. Material & methods: Patients receiving a diagnosis of BP between January 2000 and December 2019 were analyzed. Patients who developed a blister after 3 months from the onset of pruritus were considered as NBP. Demographic features, clinical findings at diagnosis and at 2-year follow-up, histological features, auto-antibodies titers, comorbidities and their treatment were retrieved. Categorical variables were evaluated for normal distribution using a histogram and a Q-Q plot. The chi(2) and Fisher's exact tests were used to compare categorical variables between the groups. Continuous variables were compared between the groups using analysis of variance and the independent-samples t test. For multivariate analysis, logistic regression was performed. Results: A total of 532 patients received a diagnosis of BP. A total of 122 patients were enrolled in the study; 63 were females, and the mean age at the diagnosis was 77.2 years (+/- 11.9 SD). 98 were affected by BP and 24 were categorized as NBP. Mean time to diagnosis was 2.9 months (+/- 5.8 SD) for BP and 30.4 months (+/- 59.8 SD) for NBP (p = 0.0001). Skin manifestations in NBP patients were, in order of frequency: urticarial, papular or nodular, eczematous, and excoriations. Pruritus intensity was high but similar in the two groups (Numerical Rating Scale - NRS, 9.3 vs. 8.9). Seven out of 24 NBP patients (29%) never developed blisters; the other patients developed blisters after a mean follow-up time of 24.9 months (+/- 54.9 SD). NBP patients had a more frequent history of myocardial infarction than BP patients (37.5 vs. 10.2%; p < 0.003). More NBP patients were taking diuretics than BP patients (66.7 vs. 49%; p = 0.03). NBP patients had a worse response to pruritus compared to BP patients at 2 years (NRS 3.7 vs. 11; p 0.001). Conclusions: NBP patients have a delayed diagnosis and may be at an increased risk of cardiovascular disease, especially myocardial infarction. Severely and persistently itchy skin disorders in aged patients should be investigated for BP diagnosis.