Bullous pemphigoid: Comparing the prevalence and severity of itch and pain.

Itch is a common symptom of bullous pemphigoid (BP) that may be the sole manifestation of disease activity.1Amato D.A. Silverstein J. Zitelli J. The prodrome of bullous pemphigoid.Int J Dermatol. 1988; 27: 560-563Crossref PubMed Scopus (28) Google Scholar Recent studies have characterized the effect of itch on quality of life (QoL) in BP. Itch was more severe in BP than that in pemphigus vulgaris and mucous membrane pemphigoid, and intensity correlated with disease severity.2Cole E.F. DeGrazia T. AlShamekh S. Feldman R. Itch-related quality of life impact across 3 autoimmune blistering diseases: a retrospective cohort studyItch (Phila). 2020; 5 (e39-e39)PubMed Google Scholar Comparatively, symptoms of pain are not characterized as well. We aimed to directly compare the prevalence of itch and pain among patients with BP and evaluate their relationship with disease activity. Initial study visits of subjects enrolled in the prospective blistering disease database at the University of Pennsylvania were reviewed. Patients were included if they met the criteria for mucosal and/or cutaneous BP and if bullous pemphigoid disease area index (BPDAI) activity scores, physician global assessment skin activity scores, and patient global assessment (PtGA) of itch and pain were completed at the study visit by the investigator (V.P.W.) and subject, respectively. Patients with non-BPs and other autoimmune bullous diseases were excluded. Based on previous reports, BPDAI of ≤19 was considered mild disease. PtGA itch scores of 3 to 7 cm and pain scores of 3.5 to 7.5 cm were considered moderate.3Masmoudi W. Vaillant M. Vassileva S. et al.International validation of the bullous pemphigoid disease area index severity score and calculation of cut-off values for defining mild, moderate and severe types of bullous pemphigoid.Br J Dermatol. 2021; 184: 1106-1112Crossref PubMed Scopus (28) Google Scholar, 4Reich A. Chatzigeorkidis E. Zeidler C. et al.Tailoring the cut-off values of the visual analogue scale and numeric rating scale in itch assessment.Acta Derm Venereol. 2017; 97: 759-760Crossref PubMed Scopus (52) Google Scholar, 5Boonstra A.M. Schiphorst Preuper H.R. Balk G.A. Stewart R.E. Cut-off points for mild, moderate, and severe pain on the visual analogue scale for pain in patients with chronic musculoskeletal pain.Pain. 2014; 155: 2545-2550Abstract Full Text Full Text PDF PubMed Scopus (359) Google Scholar Specific questions regarding itch (question 2 of autoimmune bullous disease quality of life questionnaire and question 10 of Skindex-29) and pain (question 1 of autoimmune bullous disease quality of life questionnaire and Skindex-29) were extracted from completed QoL forms and correlated with disease activity. Mean PtGA scores for pain and itch were compared among patients with erosions/blisters and urticarial/eczematous lesions. Immunosuppressant use was assessed for correlation with itch and pain. Fisher exact test, Spearman’s correlations, and Mann–Whitney U tests were used for analysis. A total of 38 subjects were included. Half (50%) were women with an average (SD) age of 77 years (11 years). Median (IQR) BPDAI and physician global assessment activity scores were 7 (20.7) and 0.95 (3.2). Itch and pain were reported by 82% and 53% of the patients, respectively. Of these, 50% reported moderate/severe itch and 26% reported moderate/severe pain (Fig 1). Median BPDAI scores for those who reported no itch (n = 7) and no pain (n = 18) were 5 and 5.5, respectively. QoL related to itching significantly correlated with disease activity compared with pain (Table I). A total of 71% and 61% subjects exhibited active blisters/erosions and urticarial/eczematous lesions, respectively. Patients with erosions or blisters reported higher average PtGA pain scores than those without (P =.041). There was no difference in the reported itch between patients with or without urticarial or eczematous lesions. There was no difference in BPDAI, physician global assessment, or PtGA visual analog scale scores between those with and without mucosal involvement (n = 11; P >.05). There was no correlation between systemic steroid use and itch or pain scores (P >.05).Table IRelationship between patient-reported outcomes and clinical measures of disease activity using Spearman’s correlationPatient-reported outcomeBPDAI activityPGA skin activitySpearman’s RhoP valueSpearman’s RhoP valuePtGA itch.321.049∗.437.006∗∗PtGA pain.308.06.414.01∗∗Skindex itch.302.066.348.032∗Skindex pain.314.055.429.007∗∗ABQOL itch.384.017∗.416.009∗∗ABQOL pain.306.062.315.054ABQOL, Autoimmune bullous disease quality of life questionnaire; BPDAI, bullous pemphigoid disease area index; PGA, physician global assessment; PtGA, patient global assessment.∗ Indicates P-value ≤.05.∗∗ Indicates P-value ≤.01. Open table in a new tab ABQOL, Autoimmune bullous disease quality of life questionnaire; BPDAI, bullous pemphigoid disease area index; PGA, physician global assessment; PtGA, patient global assessment. ∗ Indicates P-value ≤.05. ∗∗ Indicates P-value ≤.01. Even mild disease, moderate itch, and mild pain were present in most of our population and correlated with disease activity. However, subjects reported more severe itch than severe pain, and itch demonstrated a significant correlation with disease activity compared with pain. This suggests that itch plays a larger role than pain in our population with mild disease. As expected, pain may relate to the presence of erosions or blisters. Our study is limited by the small sample size. Future studies may seek to explore the relationship between itch and pain in patients with more severe diseases. This study helps to define the prevalence and severity of pain and itch, which may be informative in future BP trials. None disclosed.