Citations

Abstract Background Immune checkpoint inhibitors (ICIs) directed against PD-1, PD-L1, and CTLA-4 augment antitumor immune responses but may also induce unintended immune activation, resulting in immune-related adverse events (irAEs). Cutaneous manifestations of irAEs are among the most common, ranging from mild eruptions to severe autoimmune blistering disorders (AIBDs). Although bullous pemphigoid (BP) is the most reported ICI-related autoimmune bullous disorder (irAIBD), data on the spectrum, and management of other ICI-associated AIBDs remain limited. Understanding these reactions is crucial to managing treatment interruptions and influencing oncologic outcomes. Objective This study aims to comprehensively characterize ICI-associated irAIBDs by examining demographics, clinical presentation, disease severity, therapeutic approaches, treatment responses, clinical outcomes, and mortality. Methods A single-institution retrospective chart review was conducted, using a text-based database search from 2011–2023. Adult patients (≥18 years) with biopsy-confirmed AIBDs attributed to ICIs were included. Demographic, oncologic, and immunotherapy details, as well as clinical, histopathologic, and immunofluorescence characteristics of AIBDs, were reviewed. Treatment approaches, outcomes, and mortality data were analyzed. Results Forty-four patients with irAIBDs were identified, predominantly representing males (29, 65.9%) with a mean age of 70.4 years (range: 62-80 years). Lung carcinoma (12, 27.2%) and melanoma (9, 20.4%) were the most frequent underlying malignancies, and pembrolizumab (25, 56.8%) was the most common agent. Bullous pemphigoid (BP) accounted for most cases (36, 81.8%), followed by lichen planus pemphigoides (LPP) (6, 13.6%), with one case each of mucous membrane pemphigoid (MMP) and linear IgA bullous dermatosis (LABD). Pruritus was reported in most (42, 9%) patients, and upper (36, 81.8%), lower (32, 72.2%) extremities and the chest (34, 77.2%) were most often involved. Eosinophilic infiltration was present in most (23, 81.8%) of BP cases, and linear IgG and C3 deposition were the predominant immunofluorescence patterns in BP. Most patients received topical (34, 77.2%) and/or systemic corticosteroids (32, 72.7%), while 16 required at least temporary ICI discontinuation. Four BP (4, 9.1%) patients were treated with dupilumab. Other systemic agents used included doxycycline (22, 50%), intravenous immunoglobulin (IVIG) (5, 11.3%), rituximab (6, 13.6%), dapsone (1, 2.2%), mycophenolate mofetil (1, 2.2%), methotrexate (1, 2.2%), and colchicine (1, 2.2%). Three cases with Grade 3 severity necessitated permanent ICI discontinuation. Clinical stabilization (24, 54.5%) or remission of the irAIBD (16, 36.3%) was achieved in most cases. One death (2.2%) was attributed to sepsis in a patient with severe irAIBD. Conclusion ICI-associated AIBDs are uncommon but clinically significant complications. Most patients in our cohort continued ICI therapy during management of their irAIBD, while others required temporary or permanent interruption. These findings highlight the importance of prompt recognition and multidisciplinary management of these uncommon toxicities.

ABSTRACT Tissue‐resident memory T cells (TRMs) are a distinct memory T‐cell subset that permanently reside in tissues such as the skin. In chronic immune‐mediated dermatoses, including psoriasis, atopic dermatitis, and vitiligo, TRMs are implicated in site‐specific “disease memory,” contributing to persistence and relapse at previously affected sites. This review synthesizes emerging concepts on TRMs in chronic inflammatory skin diseases and discusses clinical and translational implications, including TRM‐targeted therapies. Original human, animal, or in vitro studies evaluating TRMs in the pathogenesis or persistence of dermatologic diseases were included. In psoriasis, CD8 + TRMs (CD69 + CD103 + ) persisted in clinically healed skin. For atopic dermatitis, both CD4 + and CD8 + TRMs are implicated in maintaining Th2/Th22 inflammation. In vitiligo, autoreactive CD8 + TRMs at lesional margins mediate melanocyte destruction. Across dermatological diseases, TRMs share three core features: persistence in previously affected skin after clinical resolution, rapid reactivation by diverse triggers (stress, autoantigens, allergens, or cytokines) leading to site‐specific recurrence, and relative resistance to conventional therapies. Together, these properties provide a unifying framework linking tissue immune memory to the chronic, relapsing nature of inflammatory skin diseases. However, the dominant TRM pathways vary by disease, reflecting differences in immune polarization and antigen specificity. Targeting TRMs represents a promising strategy for disease control and serves as a biomarker of residual disease or flare. image

Study Design: A panel of 13 clinicians with experience in dermatology and primary care was assembled to review literature regarding the diagnostic workup of scarring and nonscarring alopecias. The literature for review included clinical trials, meta-analyses, systematic reviews, and previously published guidelines from the last 10 years. After review, the panel drafted a list of consensus statements and then voted on these statements using a modified eDelphi method in order to verify the validity and clarity of each statement. Objective: Our objective, as a panel, was to formulate a clear set of guidelines in the workup of various forms of hair loss by a systematic review of clinical data and literature on the matter. Background: Hair loss is a common and frustrating medical concern for patients worldwide and accounts for significant health care utilization and cost. Moreover, hair loss may present as a symptom of an underlying medical condition requiring attention and treatment. Results: After review, the panel reached a total of 22 consensus statements regarding recommendations for diagnostic testing in the setting of hair loss, 17 of those statements focused on nonscarring alopecias, and 5 statements directed toward scarring alopecias. The statements were evaluated by members of the panel and voted on through a modified eDelphi method and discussed in an open forum. Conclusion: The panel’s review revealed that the diagnostic laboratories and/or scalp biopsy should be considered to varying degrees depending on the type of hair loss at presentation. If there is concern for a scarring process, a biopsy should be strongly considered, while serum laboratory work may be of little benefit. In nonscarring alopecias including alopecia areata, telogen effluvium, and androgenetic alopecia, the literature supports ordering certain serologic tests based on the type of hair loss at presentation.

We performed a retrospective review of patients with lichen planus pemphigoides (LPP) over almost a 23-year period to gather clinical, histopathological, immunological and treatment-related information and to compare idiopathic LPP with drug-induced LPP. This study represents the largest single-institution case series of LPP to date and includes novel findings related to mucosal involvement, autoantibody profiles and the value of monitoring bullous pemphigoid (BP) autoantibodies in predicting treatment response. This study also includes characteristic histopathological findings that can aid in the diagnosis and differentiation of LPP from BP, in addition to comparisons between idiopathic LPP and drug-induced LPP.

Abstract Acute graft-versus-host disease (GVHD), a serious complication of allogeneic hematopoietic cell transplantation (HCT), frequently involves the skin. Since clinicopathologic features of GVHD can mimic those of certain drug eruptions, accurate diagnosis can be challenging. We aimed to develop a tissue-based molecular assay to improve differentiation of GVHD from vacuolar interface drug eruption in the post-HCT period. After identifying 62 putative tissue-based biomarkers using unbiased molecular methods, we incorporated 26 into a quantitative RT-PCR assay. We tested skin biopsy specimens showing vacuolar interface changes attributable to either acute GVHD (n=67) or drug reaction (n=17), as classified by meticulous review of clinical features and course. Data were incorporated into clinical-molecular fusion diagnostic models. Significant differences in the expression of several genes, including MX1, MNDA, OAS, LIMA1, GSTM5, and SPP1, were detected between the two diagnostic groups (p<0.05). The optimal fusion model, which incorporated quantitative expression of MX1, MNDA, OAS, and GSTM5, as well as the clinical feature of diarrhea, imparted high diagnostic accuracy (receiver operating characteristic area-under-curve: 0.89). This novel tissue-based diagnostic molecular assay and fusion model demonstrates potential to improve distinction of GVHD from drug eruptions in the post-HCT setting. Multicenter validation studies are required.