Autoimmune dermatologic toxicities from immune checkpoint blockade with anti-PD-1 antibody therapy: a report on bullous skin eruptions

The role of eosinophils in the differential diagnosis of inflammatory skin diseases

Eosinophils are known to be present in inflammatory skin diseases, but their diagnostic utility is not well established. Upon review of the published status of lesional eosinophils, several categories were identified. 1) Lesional eosinophils highly characteristic such that, in their absence, the pathologist may question the diagnosis. These include arthropod bite reactions and scabies, urticarial dermatitis, and other eosinophilic dermatoses. 2) Lesional eosinophils rare or absent, such that, in their presence, the pathologist may question the diagnosis. These include pityriasis lichenoides, graft versus host disease, and connective tissue disorders. 3) Lesional eosinophils variable and, while in some cases expected, are not required for diagnosis. These include drug reactions, atopic dermatitis and allergic contact dermatitis. 4) Lesional eosinophils variable and not expected but may be seen to a limited extent. These include lichen planus and psoriasis.

Immune checkpoint inhibitor-induced cutaneous toxicities: a review of histopathologic and clinical features

Immune checkpoint inhibitors (ICIs) represent an emerging treatment option for a variety of cancer types. Through inhibition of programmed cell death protein 1 (PD-1), programmed cell death ligand 1 (PD-L1), and/or cytotoxic lymphocyte-associated antigen-4 (CTLA-4), ICIs activate the host's immune system causing a heightened anti-tumor response. However, off-target effects of ICIs can result in numerous different immune-related cutaneous adverse events (irCAEs). Beyond impacting quality of life, irCAEs can lead to dose limitations or discontinuation of anti-cancer therapies. Correct diagnosis is necessary for expedient and appropriate management. Skin biopsies are often performed to increase diagnostic accuracy and guide clinical management. An extensive literature review was performed using the PubMed database to identify the reported clinical and histopathologic features of irCAEs. This comprehensive review primarily details the histopathologic features of various irCAEs reported to date. Clinical presentation and immunopathogenesis are also discussed in relation to histopathology.

Cutaneous Side Effects of Modern Targeted Therapy and Immunotherapy in Patients with Dermatological Malignancies

The advent of immunotherapy and targeted therapies in treating dermatological malignancies has dramatically changed the landscape of dermato-oncology in recent years. Their superior efficacy compared to previous therapeutic options, such as chemotherapy, has resulted in their use in treating devastating malignancies, such as melanoma or unresectable/metastatic basal cell and squamous cell carcinoma. Skin toxicity is a critical safety consideration, among other adverse reactions, that can occur under treatment with these agents. This article aims to summarize the cutaneous side effects of immune checkpoint inhibitors and targeted dermato-oncological therapies. Although the skin side effects of these agents are primarily mild, they can occasionally affect the decision for treatment continuation and the quality of life of the affected patients. Therefore, physicians must be acquainted with the specific cutaneous toxicity profile of such treatments to mitigate their impact on the patients and optimize the overall outcome of dermato-oncological therapy.

Gene expression profiling and multiplex immunofluorescence analysis of bullous pemphigoid immune-related adverse event reveal upregulation of toll-like receptor 4/complement-induced innate immune response and increased density of TH 1 T-cells

BACKGROUND

Immune checkpoint inhibitor (ICI)-based cancer therapies cause a variety of cutaneous immune-related adverse events (irAEs) including immunobullous skin eruptions like bullous pemphigoid (BP). However, little is known about the underlying immunopathogenic drivers of these reactions, and understanding the unique gene expression profile and immune composition of BP-irAE remains a critical knowledge gap in the field of oncodermatology/oncodermatopathology.

METHODS

BP-irAE (n = 8) and de novo BP control (n = 8) biopsy samples were subjected to gene expression profiling using the NanoString® Technologies nCounter PanCancer Immune Profiling Panel. Multiplex immunofluorescence (mIF) studies using markers for T-cells (CD3 and CD8), T helper 1 (T_H 1) cells (Tbet), T_H 2 cells (Gata3), T_H 17 cells (RORγT), and regulatory T-cells (Tregs; FoxP3) were further evaluated using InForm® image analysis.

RESULTS

Compared with de novo BP controls, BP-irAE samples exhibited upregulation of 30 mRNA transcripts (p < 0.025), including toll-like receptor 4 (TLR4) and genes associated with complement activation, and downregulation of 89 mRNA transcripts (p < 0.025), including genes associated with T_H 2, T_H 17, and B-cell immune response. BP-irAE demonstrated a greater density of Tbet⁺ (T_H 1) cells in the dermis (p = 0.004) and fewer Tregs in the blister floor (p = 0.028) when compared with that of de novo control BP samples.

CONCLUSIONS

BP-irAE exhibited activation of the TLR4/complement-driven classical innate immune response pathway, with dermal T_H 1 immune cell polarization and decreased Tregs in the blister floor. TLR/complement signaling may underlie the immunopathogenesis of BP-irAE.

A Review of Bullous Dermatologic Adverse Events Associated with Anti-Cancer Therapy

The rapid evolution of anti-cancer therapy (including chemotherapy, targeted therapy, and immunotherapy) in recent years has led to a more favorable efficacy and safety profile for a growing cancer population, and the improvement of overall survival and reduction of morbidity for many cancers. Anti-cancer therapy improves outcomes for cancer patients; however, many classes of anti-cancer therapy have been implicated in the induction of bullous dermatologic adverse events (DAE), leading to reduced patient quality of life and in some cases discontinuation of life-prolonging or palliative therapy. Timely and effective management of adverse events is critical for reducing treatment interruptions and preserving an anti-tumor effect. Bullous DAE may be limited to the skin or have systemic involvement with greater risk of morbidity and mortality. We present the epidemiology, diagnosis, pathogenesis, and management of bullous DAE secondary to anti-cancer therapies to enable clinicians to optimize management for these patients.

Cutaneous lichenoid drug eruptions: A narrative review evaluating demographics, clinical features and culprit medications

Cutaneous lichenoid drug eruptions (LDE) are adverse drug reactions (ADR) characterized by symmetric, erythematous, violaceous papules reminiscent but rarely fully characteristic of lichen planus (LP). We aimed to analyse the literature describing cases of LDE within the last 20 years to provide additional insight into culprit drugs, typical latency to onset of the eruption, the spectrum of clinical presentations, severity and management. A literature search was conducted in MEDLINE between January 2000 and 27 January 2021. The keywords 'lichenoid drug rash' and 'lichenoid drug eruption' were used. Cases were included if LDE diagnosis was made, and culprit drugs were identified. A total of 323 cases with LDE were identified from 163 published case reports and studies. The mean patient age was 58.5 years (1 month to 92 years), and 135 patients (41.8%) were female. Checkpoint inhibitors (CKI) were the most frequently reported culprit drugs (136 cases; 42.1%), followed by tyrosine kinase inhibitors (TKI) (39 cases; 12.0%) and anti-TNF-α-monoclonal antibodies (13 cases; 4.0%). The latency between initiation of the drug and manifestation was 15.7 weeks (range: 0.1-208 weeks). After discontinuing the culprit drug, the median time to resolution was 14.2 weeks (range: 0.71-416 weeks). One hundred thirty-six patients (42.1%) were treated with topical, and 54 patients (16.7%) with systemic glucocorticoids. Overall, we conclude that, albeit rare, LDE is challenging to diagnose ADR induced by mostly CKI, TKI, and biologics. Treatment modalities resemble that of lichen planus, and the culprit drugs had to be discontinued in only 26%, which is low compared with other types of adverse drug reactions. This is probably due to the low risk of aggravation (e.g. toxic epidermal necrolysis) if the drug is continued and the benefit/risk ratio favouring the drug, as is often the case in cancer therapy.

Researching trends in pemphigoid diseases: A bibliometric study of the top 100 most cited publications

Background

In the field of autoimmune and inflammatory disorders, different approaches were applied to provide information regarding disease activity, comorbidities, epidemiological reports and risk factors. However, no previous studies had thoroughly analyzed the research trend in the field, and the bibliometric analysis focusing on pemphigoid diseases was available. The objective of the current study was to evaluate the current research trend in the field.

Methods

A search has been conducted for the Web of Science database based on various subcategories of pemphigoid diseases. Detailed information including articles' publication types, Author information, citation, and publication information was attained for further analysis.

Results

Within the 6,995 studies, the top 100 most-cited articles were extracted for analysis. Among the top 100 studies, 70% of the studies focused on bullous pemphigoid. More than 60% of the top 100 studies were studies with original data. Furthermore, 30% of the studies were guidelines and narrative reviews. For the issues primarily focused on, most of the high-impact studies described the molecular mechanism of pemphigoid diseases (26%), managements (19%), risk factors of pemphigoid diseases (17%). Additionally, some other studies provided general review or discussed about the issue of epidemiology, diagnosis/definition, comorbidities and clinical characteristics of pemphigoid diseases.

Conclusion

This comprehensive bibliographic study of pemphigoid diseases provided an overview of current research focuses in the field. Topics such as disease management, molecular mechanism of pathogenesis, and drug-inducing pemphigoid diseases were highly mentioned in the most-cited studies. For researchers and clinicians, the researching trend and study focus in the top-100 cited studies could serve as a potential reference for future investigation and patient management.

A case of severe nivolumab-induced lichen planus pemphigoides in a child with metastatic spitzoid melanoma

Dermatologic reactions are among the most common adverse events of antiprogrammed cell death-1 (anti-PD-1) monoclonal antibodies agents and include maculopapular rash, psoriasiform rash, lichenoid eruptions, autoimmune bullous disorders, and vitiligo. Here, we present a case of a 12-year-old African American male with metastatic spitzoid melanoma treated with nivolumab who developed a mild lichenoid eruption that progressed to a severe case of lichen planus pemphigoides (LPP). Management was complex given the patient's age and history and included hospitalization for intravenous steroids, an intensive topical steroid regimen, methotrexate, and discontinuation of nivolumab. This case illustrates a rare but dramatic progression from a mild LP-like eruption to severe bullous lichenoid eruption, most consistent with LPP, as well as the diagnostic and treatment challenges in the setting of a pediatric patient on nivolumab.

Analysis of the clinical characteristics of pembrolizumab-induced bullous pemphigoid

Background

Pembrolizumab, a programmed cell death protein 1 checkpoint inhibitor, is a novel drug used to treat a variety of advanced malignancies. However, it can also result in many immune-related adverse events, with cutaneous toxicities being the most frequent. Regarding pembrolizumab-induced skin adverse reactions, bullous pemphigoid (BP) has the worst effects on quality of life. Recently, there have been more and more reports of BP incidents resulting from pembrolizumab therapy in patients with cancer. This study aimed to define the clinical characteristics, diagnosis and management of pembrolizumab-induced BP and identify potential differences between classical BP and pembrolizumab-induced BP.

Methods

Case reports, case series, and case analyses of pembrolizumab-induced BP up to 10 December 2022 were collected for retrospective analysis.

Results

Our study included 47 patients (33 males and 14 females) from 40 studies. The median age was 72 years (range 42-86 years). The median time to cutaneous toxicity was 4 months (range 0.7-28 months), and the median time to bullae formation was 7.35 months (range 0.7-32 months). The most common clinical features were tense bullae and blisters (85.11%), pruritus (72.34%), and erythema (63.83%) on the limbs and trunk. In 20 of the 22 cases tested, the serum anti-BP180 autoantibodies were positive. However, in 10 cases (91.90%, 10/11) the circulating autoantibodies of anti-BP230 were negative. 40 patients had skin biopsies and the skin biopsy revealed subepidermal bullae or blister eosinophil infiltration in 75.00% of patients with pembrolizumab-induced BP, 10.00% of patients with lymphocyte infiltration and 20.00% of patients with neutrophil infiltration. There were 20 patients (50%) with eosinophilic infiltration around the superficial dermis vessels, 8 patients (20.00%) with lymphocyte infiltration around the superficial dermis vessels, and 4 patients (10.00%) with neutrophil infiltration around the superficial dermis vessels. Direct immunofluorescence detected linear immunoglobulin G (IgG) IgG and/or complement C3 along the dermo-epidermal junction in 36 patients (94.74%) with BP. IgG positivity was detected by indirect immunofluorescence in 81.82% of patients with BP. All patients were in complete remission (95.65%,44/46) or partial remission (4.35%, 2/46) of BP, whereas 9/46 patients had a relapse or refractory. The majority of patients achieved BP remission after discontinuation of pembrolizumab with a combination of topically and systemically administered steroid treatments, or other medications. The median duration of BP remission was 2 months (range 0.3-15 months).

Conclusion

A thorough diagnosis of pembrolizumab-induced BP should be made using clinical signs, biochemical markers, histopathological and immunopathological tests. Pembrolizumab-induced BP had similar clinical characteristics to classic BP. Temporary or permanent discontinuation of pembrolizumab therapy may be required in patients with perbolizumab-induced BP depending on the severity of BP and the response to medication. Pembrolizumab-induced BP may be effectively treated using topical and systemic steroid treatments in combination with other medications (e.g., doxycycline, niacinamide, dapsone, rituximab, intravenous immunoglobulins, dupilumab, cyclophosphamide, methotrexate, mycophenolate mofetil, and infliximab). Clinicians should provide better management to patients with BP receiving pembrolizumab to prevent progression and ensure continuous cancer treatment.

Checkpoint inhibitor-associated bullous cutaneous immune-related adverse events: a multicentre observational study

BACKGROUND

Checkpoint inhibitor (CPI) therapy has significantly improved overall survival in several cancers including metastatic melanoma (MM) and in the adjuvant setting. Cutaneous immune-related adverse events (irAEs) secondary to CPIs are commonly observed; however, autoimmune blistering disorders such as bullous pemphigoid (BP) are rare.

OBJECTIVES

To review the prevalence, incidence risk, clinicopathological features and management of toxicity in bullous cutaneous irAEs associated with CPI therapy.

METHODS

A multicentre, retrospective, observational study of CPI-associated bullous irAEs in adults with all cancers across four UK specialist centres between 2006 and 2019.

RESULTS

In total, 7391 patients were identified. CPI-associated bullous irAEs including BP (n = 16) occurred in 0·3% (n = 22). The median age of onset was 76 years, and there was a male predominance. Most patients had cutaneous melanoma (73%, n = 16), of which 81% (13 of 16) were BRAF wildtype. Grade 1, 2, 3 and 4 skin toxicity occurred in 9%, 45%, 41% and 5%, respectively. The mucosae were involved in 27%, and 25% of confirmed cases of BP did not present with bullae. The median time to onset of bullous irAEs was 12 months, with a median total symptom duration of 6 months. Single PD-1/PD-L1 agents had a longer time to onset of symptoms than combination therapy (median 12 vs. 7 months, respectively). Overall, 91%, 64% and 9% of patients required one, two or three lines of treatment, respectively. Two cases occurred after completion of CPIs (1 and 3 months). Of the 20 cases that presented while on CPIs this was permanently discontinued in 55% (11 of 20) and temporarily held in 20% (four of 20). In the four held cases of CPI, bullous eruption reflared in 50%.

CONCLUSIONS

CPI-associated bullous skin toxicity is a rare cutaneous irAE occurring in approximately 0·3% of cases over 13 years of treated patients in this series. Not all cases are diagnostic of BP, but management remains the same. There is a prolonged latency of onset compared with other cutaneous irAEs, with a median time of 12 months, and they can occur after cessation of therapy. Discontinuation of CPIs may be required. Recognizing bullous irAEs promptly and referral to dermatology are essential to optimize management and improve patient outcomes and tumour responses. What is already known about this topic? Checkpoint inhibitor (CPI)-associated bullous pemphigoid is a rare dermatological immune-related adverse event (irAE) that has been reported in small case series and reports. What does this study add? This is the largest multicentre, observational study conducted in the UK over the longest period of 13 years, which demonstrates an overall incidence of bullous cutaneous irAEs secondary to CPIs of 0·3%. Clinical presentation is variable, with one-quarter of patients with bullous pemphigoid presenting without bullae, and mucosal involvement was noted in 27%. Prolonged pruritus is frequently a prodromal symptom. The median time to diagnosis is 12 months and irAEs rarely present after cessation of treatment. Time to onset of symptoms is longer with a single CPI, but with a shorter duration of symptoms compared with combination CPI therapy. Most patients had cutaneous melanoma, of which 81% were BRAF wildtype.

A Retrospective, Single-Institution Experience of Bullous Pemphigoid as an Adverse Effect of Immune Checkpoint Inhibitors

Simple Summary

This article investigates the cutaneous adverse immune effects induced by immune checkpoint inhibitors. These drugs target proteins expressed on cancer cells that aid in the avoidance of immune system detection and destruction. Immune checkpoint inhibitors inadvertently cause other immune-mediated adverse effects. Cutaneous toxicities are the commonest adverse effect from immunotherapy; furthermore, they are usually developed early in the course of treatment. A rare and severe cutaneous adverse event is Bullous Pemphigoid. This article investigates the average and median onset of these drug toxicities, as well as treatments. We found these side effects to be negatively skewed, indicating most cases occur several months into treatment.

Abstract

Immune checkpoint inhibitors are a class of cancer treatment drugs that stimulate the immune system’s ability to fight tumor cells. These drugs are monoclonal antibodies targeting im-mune-inhibiting proteins on cancer cells, such as CTLA-4 and PD-1/PD-L1. Immune checkpoint inhibitors cause many immune-related adverse events. Cutaneous toxicities are of the most common adverse effects and occur with a range of severity. Bullous Pemphigoid is a rare adverse event with a high impact on quality of life that may occur after immune checkpoint inhibitor treatment. In this article, we investigate current research on immune checkpoint inhibitors, cutaneous adverse events, and common presentations and treatments, with a specific focus on Bullous Pemphigoid, its characteristics, onset timing, and treatment. Significant findings include a negative skew in the onset of presentation. Furthermore, we describe exclusive cases.

Hemidesmosomal Reactivity and Treatment Recommendations in Immune Checkpoint Inhibitor-Induced Bullous Pemphigoid—A Retrospective, Monocentric Study

Immune checkpoint inhibitors (ICI) induce T-cell-mediated antitumour responses. While ICI were initially successfully applied in metastasized melanoma, they are now approved for several tumour entities. Numerous autoimmune disorders have been reported to occur as adverse events of the treatment, among them bullous pemphigoid (BP), with less than 1% of the patients experiencing ICI-induced BP. This number is higher than the estimated prevalence of autoimmune bullous diseases in the general population of Germany, which lies around 0.05%. We here describe our cohort of eight patients, who developed a bullous pemphigoid under or shortly after ICI treatment. Half of them had a severe subtype (as shown by BPDAI >57) and showed a median onset of ICI-BP after 10 months of ICI initiation. Six patients had a palmar and/or plantar involvement, while oral involvement occurred in one case. All patients had linear epidermal IgG depositions in split skin in the indirect immunofluorescence. In four out of five biopsies available for direct immunofluorescence, linear IgG and C3 depositions were detected at the basement membrane, while one patient showed linear IgM staining. Moderate to high levels of FLBP180 autoantibodies were found in seven of eight cases. The disease can still be active after ICI discontinuation, while rituximab might be required for remission. Finally, four tumour samples were stained histochemically for collagen XVII (BP180), but no enhanced expression was found.

Cutaneous adverse events of immune checkpoint inhibitor therapy: incidence and types of reactive dermatoses

BACKGROUND

Dermatoses are common and potentially serious complications of programmed cell death receptor PD-1 immune checkpoint inhibitor (anti-PD-1 ICI) therapy. Understanding their incidence is necessary to support clinical awareness, diagnosis, and management.

OBJECTIVE

To examine the incidence and odds of reported non-cancerous dermatoses in the setting of anti-PD-1 ICI therapy.

METHODS

Cross-sectional study of anti-PD-1 (pembrolizumab or nivolumab) treated patients at a tertiary healthcare institution. Selected dermatologic events following immunotherapy were identified in the electronic medical record. Comparator arm were patients that developed these same dermatoses without receiving anti-PD-1 ICI therapy.

RESULTS

There were 13.7% (254/1857) patients that developed one of 28 dermatoses. Compared with the general population, patients treated with anti-PD-1 had a greater risk for development of mucositis (OR 65.7, 95% CI 35.0-123.3), xerostomia (OR 11.9, 95% CI 8.4-16.8), pruritus (11.3, 95% CI 8.9-14.3), and lichen planus/lichenoid dermatitis (OR 10.7, 95% CI 5.6-20.7).

CONCLUSIONS

We report the frequency of dermatoses encountered in the setting of ICI therapy, both common (pruritus, rash, vitiligo) and uncommon (scleroderma, urticaria).

Immune cell subsets in interface cutaneous immune-related adverse events (cirAEs) associated with anti-PD-1 therapy resemble acute graft vs host disease more than lichen planus

Background

Checkpoint immunotherapy is frequently associated with cutaneous immune‐related adverse events (cirAEs), and among those, the most common subtype shows interface reaction patterns that have been likened to lichen planus (LP); however, cutaneous acute graft versus host disease (aGVHD) may be a closer histopathologic comparator. We used quantitative pathology to compare the immunologic composition of anti‐PD‐1‐associated interface reactions to LP and aGVHD to assess for similarities and differences between these cutaneous eruptions.

Methods

Immunohistochemistry for CD4, CD8, CD68, PD‐1, and PD‐L1 was performed on formalin‐fixed paraffin‐embedded tissue from patients with anti‐PD‐1 interface cirAEs (n = 4), LP (n = 9), or aGVHD (n = 5). Densities of immune cell subsets expressing each marker were quantified using the HALO image analysis immune cell module. Plasma cell and eosinophil density were quantified on routine H&E slides.

Results

Specimens from patients with anti‐PD‐1 interface cirAEs showed equivalent total cell densities and immune cell composition to those with aGVHD. Patients with LP showed higher total immune cell infiltration, higher absolute T‐cell densities, increased CD8 proportion, and reduced histiocytic component. The cases with the highest plasma cell counts were all anti‐PD‐1 interface cirAEs and aGVHD.

Conclusion

The composition of immune cell subsets in anti‐PD‐1 interface cirAEs more closely resembles the immune response seen in aGVHD than LP within our cohort. This warrants a closer look via advanced analytics and may have implications for shared pathogenesis and potential treatment options.

Bullous Pemphigoid in Patients Receiving Immune-Checkpoint Inhibitors and Psoriatic Patients—Focus on Clinical and Histopathological Variation

Background: The most common autoimmune blistering disease, bullous pemphigoid (BP), shows an increased prevalence in psoriatic patients and oncologic patients undergoing immune-checkpoint blockade (ICB). Even though the same autoantigens (BP180/BP230) are detectable, it remains obscure whether clinical or histopathological differences exist between these different groups of BP patients. In this study, we strived to analyze this matter based on own data and previously published reports. Methods: We performed an institutional chart review from 2010–2020 to identify BP patients with psoriasis (n = 6) or underlying ICB (n = 4) and matched them with idiopathic cases of BP (n = 33). We compared clinical characteristics, subtypes, and dermatopathological determinants (e.g., tissue eosinophilia/neutrophilia, papillary edema, lymphocytic infiltration) among the groups. Results: ICB-associated BP affects men more often and might show mucosal involvement more frequently. We found no statistically significant dermatopathological differences among the groups. Conclusions: Clinicians should be aware of an increased risk of BP in patients with psoriasis and oncologic patients receiving ICB; atypical pruritic skin lesions should prompt a workup including a skin biopsy for histopathology and direct immunofluorescence in these patients. Larger studies might be necessary to detect slight dermatopathological variation.

Oral Immune-Related Adverse Events Caused by Immune Checkpoint Inhibitors: Salivary Gland Dysfunction and Mucosal Diseases

Conventional chemotherapy and targeted therapies have limited efficacy against advanced head and neck squamous cell carcinoma (HNSCC). The immune checkpoint inhibitors (ICIs) such as antibodies against CTLA-4, PD-1, and PD-L1 interrupt the co-inhibitory pathway of T cells and enhance the ability of CD8+ T cells to destroy tumors. Even in advanced HNSCC patients with recurrent diseases and distant metastasis, ICI therapy shows efficiency and become an effective alternative to conventional chemotherapy. However, as this therapy releases the immune tolerance state, cytotoxic CD8+ T cells can also attack organs and tissues expressing self-antigens that cross-react with tumor antigens and induce immune-related adverse events (irAEs). When patients with HNSCC are treated with ICIs, autoimmune diseases occur in multiple organs including the skin, digestive tract, endocrine system, liver, and respiratory tract. Treatment of various malignancies, including HNSCC, with ICIs may result in the appearance of oral irAEs. In the oral cavity, an oral lichenoid reaction (OLR) and pemphigoid develop. Sicca syndrome also occurs in association with ICIs, affecting the salivary glands to induce xerostomia. It is necessary to elucidate the pathogenic mechanisms of these intractable diseases that are not seen with conventional therapy. Early diagnosis and appropriate approaches to irAEs are needed for efficient treatment of advanced HNSCC by ICIs.

Immune-Related Oral, Otologic, and Ocular Adverse Events

Emerging immunotherapeutic agents, including immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death protein ligand 1 (PD-L1), have revolutionized cancer treatment. The first immune checkpoint inhibitor (ICI) ipilimumab, an anti-CTLA-4, was approved in 2011. Since then, the US Food and Drug Administration (FDA) has approved more than half a dozen immune checkpoint inhibitors to treat various malignancies. These agents are part of a broader class of chemotherapy agents termed immunotherapy, which selectively target different steps in the immune response cascade to upregulate the body's normal response to cancer. While the effects of traditional chemotherapy are well known, the toxicity profile of emerging immune therapies is not fully elucidated. They have been associated with atypical side effects labeled collectively as immune-related adverse events (irAEs).

Nivolumab induced localized genital bullous pemphigoid in a 60-year-old male

A 60-year-old male with metastatic renal cell carcinoma presented with a 6-month history of a pruritic, exquisitely painful genital eruption appearing 3 months after initiation of nivolumab. Examination demonstrated a poorly defined, lichenified scrotal plaque studded with erosions, yellow crust and tense vesicles. There was no other lesion on the body or mucosae. Histopathology revealed a subepidermal blister with a mixed lymphocytic, neutrophilic and eosinophilic infiltrate. Direct immunofluorescence of perilesional skin demonstrated subclinical blister and linear/fibrillary patchy IgG and IgA along the dermoepidermal junction. Bullous pemphigoid (BP) serologies revealed normal IgG BP230 antibodies and minimally elevated IgG BP180 antibodies. Indirect immunofluorescence revealed positive IgG at the basement membrane ("epidermal pattern") in human split skin and monkey esophagus substrates; no IgA antibodies were detected. The patient was diagnosed with nivolumab-induced localized genital BP (LGBP). BP is a reported adverse effect of immune checkpoint inhibitors including nivolumab; however, cases are typically generalized.^1,2 LGBP is a rare BP variant typically presenting in children and females; there are few reports of LGBP in adult males.^2,3 We report a novel case of nivolumab-induced LGBP with unique histopathologic and clinical challenges. LGBP should be considered in patients on immune checkpoint inhibitor therapy with bullous genital eruptions. This article is protected by copyright. All rights reserved.

Oral Immune-Related Adverse Events - Current Concepts and their Management

Recent advent of immune checkpoint inhibitors (ICIs) have made significant improvement in the treatment outcome of cancer patients. They are also known to increase the overall survival in many malignancies. They target key immune checkpoints, acting on the cytotoxic T-lymphocyte antigen-4, programmed death-1 (PD-1), and PD-1 ligand 1 pathways. ICIs are effective in cancer therapy, but also possess various adverse effects that are termed together as immune-related adverse events (irAEs). Information focusing only on the oral reactions of irAEs is scanty in the literature. Therefore, we performed a computerized database search in PubMed and Google Scholar to identify and collect data regarding the oral adverse effects of ICIs. The early recognition of oral irAEs and appropriative intervention may help in improving the quality of life in patients. This paper presents a brief review of oral irAEs and their management.

Dermatologic Toxicities of Targeted Therapy and Immunotherapy in Head and Neck Cancers

Treatment of head and neck cancers requires multidisciplinary collaboration to reduce morbidity and mortality associated with the tumor burden, as well as to preserve function of organs and structures. With the use of various new targeted therapies come new adverse events including dermatologic toxicities, which may consist of xerosis, nail and hair changes, morbilliform or papulopustular rashes, to more severe eruptions such as Stevens–Johnson syndrome. We describe the dermatologic toxicities and corresponding grades of severity and associated pathophysiology resulting from seven therapeutics used to treat head and neck cancers: cetuximab, trastuzumab, pembrolizumab, nivolumab, lentatinib, larotrectinib, and entrectinib. Being familiar with these dermatologic toxicities allows clinicians to provide comprehensive counseling for patients, encourage preventative measures, and to know when it is appropriate to hold therapy or permanently stop treatment.

Cutaneous Toxicities in the Setting of Immune Checkpoint Blockade:: The Era of Oncodermatopathology

Advancements in cancer therapy with monoclonal immune checkpoint antibody blockade have impacted the practice of all medical specialties. Cutaneous immune-related adverse events (irAEs) are a frequent, unintended, off-target consequence of immune checkpoint inhibitor (ICI) therapy that have ushered in the era of oncodermatopathology. Knowledge of the diverse morphologic types of cutaneous irAEs from ICI therapy allows further classification of cutaneous irAEs according to major histopathologic reaction patterns. Early studies suggest that immune mechanisms of lichenoid dermatitis irAE, psoriasiform dermatitis irAE, and bullous pemphigoid irAE show some similarities and differences from their histopathologic counterparts not associated with ICI therapy.

Steroid-refractory dermatologic and pulmonary toxicity in a patient on rituximab treated with pembrolizumab for progressive urothelial carcinoma: a case report

BACKGROUND

Increasingly widespread use of programmed cell death protein 1 (PD-1) immune checkpoint inhibitors (ICIs) for treatment of a variety of progressive malignancies continues to reveal a range of immune-related adverse events (irAEs), necessitating immunosuppressive therapy for management. While a single course of systemic corticosteroids may be sufficient for many irAEs, no clear standard-of-care guidelines exist for steroid-refractory cases. We present an unusual case of a patient who developed several steroid-refractory novel irAEs on pembrolizumab despite ongoing B cell-directed immunosuppressive therapy with rituximab, who ultimately noted resolution of symptoms with tacrolimus, a T-cell-directed immunosuppressant.

CASE PRESENTATION

This 72-year-old Caucasian man with Waldenstrom's macroglobulinemia and myelin-associated glycoprotein (MAG) immunoglobulin M (IgM) antibody-associated neuropathy was being treated with maintenance rituximab and intravenous immunoglobulin when he was started on pembrolizumab (2.26 mg/kg) for metastatic urothelial cancer 31 months after surgery and adjuvant chemotherapy. After his third dose of pembrolizumab, he developed a painful blistering papular rash of the distal extremities. He received two more doses of pembrolizumab before he also developed diarrhea, and it was held; he was initiated on 1 mg/kg prednisone for presumed ICI-induced dermatitis and colitis. Skin biopsy 10 weeks after cessation of pembrolizumab and taper of steroids to 20  mg daily revealed a unique bullous erythema multiforme. He was then admitted with dyspnea and imaging concerning for necrotizing pneumonia, but did not respond to antibiotic therapy. Bronchoscopy and biopsy revealed acute fibrinous organizing pneumonia. His symptoms failed to fully respond to multiple courses of high-dose systemic corticosteroids and a trial of azathioprine, but pneumonia, diarrhea, and skin rash all improved markedly with tacrolimus. The patient has since completed his therapy for tacrolimus, continues off of ICI, and has not experienced a recurrence of any irAEs, though has more recently experienced progression of his cancer.

CONCLUSION

Despite immunosuppression with rituximab and intravenous immunoglobulin, two immunomodulators targeting B cells, ICI cessation, and systemic corticosteroid therapy, our patient developed two high-grade unusual irAEs, bullous erythema multiforme and acute fibrinous organizing pneumonia. Our patient's improvement with tacrolimus can offer critical insight into the pathophysiology of steroid-refractory irAEs.

Oral Manifestations in Melanoma Patients Treated with Target or Immunomodulatory Therapies

BACKGROUND

BRAF (v-raf murine sarcoma viral oncogene homolog B1) and MEK (mitogen activated protein kinase) inhibitors, as well as immunotherapy against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death 1 (PD-1) receptor and its ligand (PD-L1), have shown good results in improving the disease-free survival of patients with metastatic melanoma (MM). The aim of this review is to summarize the main oral adverse events (oAEs) occurring in patients undergoing target or immunotherapy. We proposed two separate sections: oAEs during the treatment with (1) target therapies with BRAF and MEK inhibitors and tyrosine kinase inhibitors (gingival hyperplasia, pigmentation disorders, squamo-proliferative lesions) and (2) immunotherapies with CTLA-4 or PD1 inhibitors (lichenoid reactions, immuno-bullous reactions, xerostomia and other reactions). Adverse events frequently include oAEs, although these are often misdiagnosed and under-reported. Indeed, the oral cavity is not routinely evaluated during clinical practice. The symptomatology related to oAEs is significant since it may represent the first manifestation of a severe systemic reaction, possibly leading to difficulties in nutrition with a consequent impact on patients' quality of life. A careful examination of the oral cavity is recommended during the evaluation of oncologic patients in order to promptly detect the onset of new manifestations.

Retrospective Analysis of Checkpoint Inhibitor Therapy-Associated Cases of Bullous Pemphigoid From Six German Dermatology Centers

Immune-related adverse events (irAEs) are a class-effect of checkpoint inhibitors (CIs). The development of a Bullous pemphigoid (BP)-like blistering disease, driven by autoantibodies against the hemidesmosomal protein BP180, is a potentially serious irAE whose incidence seems to be increasing. We therefore set out to characterize the clinical and (immuno)histopathological features and treatment responses of cases of BP which developed during or after CI therapy collated in six German tertiary referral centers between 2014 and 2018. We identified twelve cases of BP which emerged during and/or after CI therapy. The time interval between the initiation of CI therapy and the diagnosis of BP was 3-74 weeks (median: 23 weeks). Age at the time of diagnosis of BP varied between 62 and 80 years (median: 76 years). The clinical presentation of the patients was diverse but the severity was relatively mild when compared to that seen in most cases of spontaneous BP. Only four patients met all of the immunopathological criteria recommended in the European guidelines for the diagnosis of BP. Topical corticosteroid treatment was sufficient to achieve disease control in most patients. CI therapy could be continued in 8 out of 12 patients. In summary, our study indicates that cases of BP during or after CI therapy bear several peculiarities distinguishing them from spontaneous BP. Given the diversity of the clinical presentation of CI-induced BP the application of existing diagnostic algorithms developed for spontaneous BP can be utilized to uncover the frequency and features of CI-induced BP and to develop and optimize management algorithms.

Bullous Pemphigoid: Trigger and Predisposing Factors

Bullous pemphigoid (BP) is the most frequent autoimmune subepidermal blistering disease provoked by autoantibodies directed against two hemidesmosomal proteins: BP180 and BP230. Its pathogenesis depends on the interaction between predisposing factors, such as human leukocyte antigen (HLA) genes, comorbidities, aging, and trigger factors. Several trigger factors, such as drugs, thermal or electrical burns, surgical procedures, trauma, ultraviolet irradiation, radiotherapy, chemical preparations, transplants, and infections may induce or exacerbate BP disease. Identification of predisposing and trigger factors can increase the understanding of BP pathogenesis. Furthermore, an accurate anamnesis focused on the recognition of a possible trigger factor can improve prognosis by promptly removing it.

Hypertrophic lichenoid dermatitis immune-related adverse event during combined immune checkpoint and exportin inhibitor therapy: A diagnostic pitfall for superficially invasive squamous cell carcinoma

Immune checkpoint inhibitors (ICIs) for cancer treatment have revolutionized the field of medicine. However, an unintended but frequent consequence of ICI therapy is the development of cutaneous immune-related adverse events (irAEs), such as lichenoid dermatitis irAEs (LD-irAEs). The hypertrophic variant of LD-irAE may be a diagnostic challenge since it can mimic superficially invasive squamous cell carcinoma (SCC). A 79-year-old woman with metastatic melanoma who began treatment with an ICI-pembrolizumab-plus exportin-1 (XPO1) inhibitor presented after 1 month of therapy with symmetrical violaceous papules coalescing into plaques and with two nodules of the bilateral dorsal hands. Biopsy of the nodules revealed an actinic keratosis and atypical epidermal proliferation concerning for SCC. However, in the ensuing 3 weeks, the patient developed multiple new erythematous, violaceous, and scaly macules and papules, some coalescing into plaques on the extremities. Biopsies of these lesions revealed exuberant irregular epidermal hyperplasia with hypermaturation and lichenoid infiltrate concentrated at the base of the elongated, broadened rete ridges, consistent with hypertrophic LD-irAE. Treatment included topical fluocinonide ointment, intralesional triamcinolone injections and oral acitretin. Distinguishing hypertrophic LD-irAE and SCC can be challenging since both entities share histopathologic features; thus, correlation with clinical presentation is essential for diagnosis and optimal patient management.

Bullous pemphigoid in elderly woman affected by non-small cell lung cancer treated with pembrolizumab: A case report and review of literature

INTRODUCTION

Immunotherapy has changed the management of patients with various types of malignancies (melanoma, renal, lung, and bladder cancers) but immune checkpoint inhibitors may be associated with several adverse events. Up to 20% of patients treated with immune checkpoint inhibitors may develop dermatological immune-related adverse events, mostly rashes and pruritus but rarely even bullous pemphigoid.

CASE REPORT

We report a case of an elderly patient with advanced non-small cell lung cancer in therapy with pembrolizumab, 200 mg/body every three weeks. After 26 cycles of therapy, the patient developed widespread itching and then after 28 cycles she developed strained blisters filled with serous fluids on predominantly erythematous skin with suspicious of bullous pemphigoid.Management and outcome: Skin biopsy confirms bullous pemphigoid, so we decided to permanently discontinue therapy with pembrolizumab and the patient is currently on therapy with doxycycline, nicotinamide, and clobetasol propionate with good regression of symptoms and cutaneous lesions.

DISCUSSION

In the literature, the first case of bullous pemphigoid induced by pembrolizumab has been described in 2015. On Pubmed, from 2015 to date, we have found 19 cases of bullous pemphigoid during pembrolizumab therapy but only three of them are related to non-small cell lung cancer, adding our patient we reach a total of 20 cases. It could be interesting to investigate if there is a specific relationship between the appearance of itching and the development of bullous pemphigoid.

Cutaneous Immune-Related Adverse Events (irAEs) to Immune Checkpoint Inhibitors: A Dermatology Perspective on Management [Formula: see text]

Immune checkpoint inhibitors have proven to be efficacious for a broad spectrum of solid organ malignancies. These monoclonal antibodies lead to cytotoxic T-cell activation and subsequent elimination of cancer cells. However, they can also lead to immune intolerance and immune-related adverse event (irAEs) that are new and specific to these therapies. Cutaneous irAEs are the most common, arising in up to 34% of patients on PD-1 inhibitors and 43% to 45% on CTLA-4 inhibitors. The most common skin manifestations include maculopapular eruption, pruritus, and vitiligo-like lesions. A grading system has been proposed, which guides management of cutaneous manifestations based on the percent body surface area (BSA) involved. Cutaneous irAEs may prompt clinicians to reduce drug doses, add systemic steroids to the regiment, and/or discontinue lifesaving immunotherapy. Thus, the goal is for early identification and concurrent management to minimize treatment interruptions. We emphasize here that the severity of the reaction should not be graded based on BSA involvement alone, but rather on the nature of the primary cutaneous pathology. For instance, maculopapular eruptions rarely affect <30% BSA and can often be managed conservatively with skin-directed therapies, while Stevens-Johnson syndrome (SJS) affecting even 5% BSA should be managed aggressively and the immunotherapy should be discontinued at once. There is limited literature available on the management of the cutaneous irAEs and most studies present anecdotal evidence. We review the management strategies and provide recommendations for psoriatic, immunobullous, maculopapular, lichenoid, acantholytic eruptions, vitiligo, alopecias, vasculitides, SJS/toxic epidermal necrolysis, and other related skin toxicities.

Cutaneous immune-related adverse events to checkpoint inhibitors

The development of immunotherapy has led to a paradigm shift in the treatment of both solid and hematologic malignancies. As immunomodulatory therapies are employed with increasing frequency, a greater number of immune-related adverse reactions are being reported, and the majority of these involve the skin. As a result, dermatologists are increasingly becoming involved in the management of these cutaneous adverse reactions-often providing critical recommendations regarding ongoing cancer treatment. Cutaneous immune-related adverse reactions can vary significantly from patient to patient, making early recognition and timely intervention imperative to mitigate associated morbidity and potential treatment interruption. Although there is considerable overlap in the cutaneous adverse events caused by these immune checkpoint inhibitors, specific eruptions are characteristically associated with particular checkpoint inhibitors. In addition, a patient's comorbidities or immune status can play a significant role in the presentation and management of such adverse reactions. This review characterizes and provides management guidelines for the various cutaneous toxicities associated with checkpoint inhibitor therapy, including CTLA-4 inhibitors, PD-1 inhibitors, and PD-L1 inhibitors. © 2020 Elsevier Inc. All rights reserved.

Dermatologic toxicities to immune checkpoint inhibitor therapy: A review of histopathologic features

Antineoplastic agents that use the immune system have revolutionized cancer treatment. Specifically, implementation of immune checkpoint inhibitors, monoclonal antibodies that block cytotoxic T-lymphocyte-associated antigen-4, programmed cell death protein 1, or programmed cell death ligand 1 show improved and sustained responses in patients with cancer. However, these agents are associated with a plethora of adverse events, many manifesting in the skin. As the clinical application of cancer immunotherapies expands, understanding the clinical and histopathologic features of associated cutaneous toxicities becomes increasingly important to dermatologists, oncologists, and pathologists to ensure timely diagnosis and appropriate care. This review discusses cutaneous reactions to immune checkpoint inhibitors, focusing on histopathologic features.

Cutaneous adverse reactions to anti-PD-1 treatment-A systematic review

The use of the humanized monoclonal anti-programmed cell death 1 antibodies pembrolizumab and nivolumab as potent anticancer therapies is rapidly increasing. However, since their approval, numerous cases of cutaneous reactions have been reported. Cutaneous adverse reactions to these agents have yet to be fully characterized and range from nonspecific eruptions to recognizable skin manifestations, which may be localized and vary from mild to life threatening. This systematic review article provides an overview of the various adverse cutaneous reactions to pembrolizumab and nivolumab therapy and offers suggestions for their management.

Ipilimumab/nivolumab-induced pseudolymphoma in a patient with malignant melanoma

Combination therapy with ipilimumab and nivolumab is an adjuvant treatment approach for metastatic melanoma that boasts increased 3-year survival when compared with a single immunotherapy agent. Combination therapy, however, is associated with increased toxicities, especially cutaneous side-effects. Here we present a patient with metastatic melanoma and a sudden eruption of painful nodules on the face and arms 10 days after the administration of the fourth dose of combination ipilimumab/nivolumab. Biopsies demonstrated lymphoid hyperplasia, not clinically or pathologically consistent with an infectious, malignant or autoimmune etiology; a diagnosis of pseudolymphoma secondary to ipilimumab/nivolumab was made. After a steroid taper, the lesions resolved, and the patient was restarted on nivolumab monotherapy 2 weeks later without recurrence of symptoms or disease.

Cutaneous Adverse Events of Anti-PD-1 Therapy and BRAF Inhibitors

OPINION STATEMENT

The treatment of advanced melanoma has undergone a dramatic transformation over the last decade with the advent of targeted and immunomodulatory therapies. This transition from cytotoxic chemotherapy has yielded improvements in both survival and quality of life; yet despite their therapeutic advantages, these treatments have been associated with a diverse range of cutaneous adverse events (AEs). These range from relatively benign eczematous conditions to more severe inflammatory and bullous disorders, and can include induction of second malignancies. AEs can result in serious morbidity and risk of mortality if not recognised and managed early. As a consequence of their novelty, and rapid uptake, these agents have been subject to intense scrutiny and there is a general understanding that cutaneous AEs should be anticipated in treatment plans. Dermatologists should be integrated into management teams to assist in the development of treatment protocols for anticipated common AEs and to provide expert management of more severe, rare or unusual AEs. Our experience has shown a reduction in treatment interruptions, more rapid recognition of unusual AEs and improved management pathways for patients suffering cutaneous AEs.

A Case of Nivolumab-Induced Cutaneous Toxicity with Multiple Morphologies

Cutaneous reactions are among the most prevalent immune-related adverse events in patients treated with immunotherapy. Given that immunotherapies often act through blocking inhibitory signals on T cells, these treatments also have the potential to generate a host of immune toxicities. We report the case of a 73-year-old woman with a history of non-small cell lung cancer treated with nivolumab 10 months prior to presentation who developed painful nodules, bullae, and a scaly rash on her extremities. Four months after discontinuation of nivolumab, she noted an acute eruption of painful nodules on her extremities, followed by pink papules and tense bullae on her palms and soles. Biopsies were performed of three lesions in sites of varying morphologies. These findings were felt to be consistent with a nivolumab-induced lichenoid reaction. She was initially treated with intralesional steroid injections, topical steroid ointment, and liquid nitrogen cryotherapy with minimal improvement. As the lesions continued to progress, the patient was admitted to the hospital and started on intravenous methylprednisolone. She eventually transitioned to daily oral prednisone with a slow taper with good effect and no recurrence of lesions.

Immune-Related Oral, Otologic, and Ocular Adverse Events

Emerging immunotherapy agents, such as immune checkpoint inhibitors, have shown remarkable promise in the treatment of various malignancies. These drugs selectively target different steps in the immune response cascade to upregulate the body's normal response to cancer. Due to the novelty of these therapeutic agents, their toxicity profile is less well understood.Meta-analysis results reveal that the overall prevalence of oral mucositis, stomatitis, and xerostomia is lower with checkpoint inhibitors compared to conventional chemotherapy, and head and neck radiation therapy. However, the widespread use of immunotherapy reveals new oral mucosal barrier adverse events, including bullous pemphigoid, mucous membrane pemphigoid, and lichenoid mucositis. Audiovestibular dysfunction can occur from autoimmune-mediated pathways of immunotherapy (adoptive cell) with limited treatment options. Such auditory complications can lead to speech recognition deficits and sensorineural hearing loss. Ocular toxicities are among the most common adverse events resulting from the use of these agents. The majority of ocular immune-related adverse events (irAEs) are mild, low-grade, non-sight threatening, such as blurred vision, conjunctivitis, and ocular surface disease. Serious and sight-threatening events, including corneal perforation, optic neuropathy, and retinal vascular occlusion, can occur but are infrequent. In this chapter, we review the current evidence on the clinical manifestations of oral, audiovestibular, and ocular immune-related adverse events (i.e., irAEs).

Pathology of immune-mediated tissue lesions following treatment with immune checkpoint inhibitors

Immune check point inhibitor (CPI) therapy has revolutionized treatment paradigms for several cancers, but at the cost of triggering a diverse spectrum of immune-mediated injury to non-cancer tissues. The complex biology of these toxicities remains incompletely understood, partly because tissue acquisition from affected areas can be challenging to retrieve, thus hindering development of targeted therapy. Here, we review the literature describing pathology of immune-mediated tissue lesions including gastrointestinal, skin, rheumatic, pulmonary, cardiac, renal and hepatic lesions and highlight key immunological insights.

Recurrence of Pemphigus Vulgaris Under Nivolumab Therapy

For many types of cancer, immune checkpoint inhibitors have proven to be a highly effective treatment. The monoclonal anti-PD-1 antibody nivolumab stimulates the immune system and is one of the newest treatment options for non-small cell lung cancer. In doing so, immune checkpoint inhibitors can trigger many skin lesions that have not yet been completely investigated in their entirety. In this case report, pemphigus vulgaris is identified as a potential adverse event that occurs under the treatment with nivolumab. In addition to the standard methods, we examined our patient's samples with ex vivo confocal laser scanning microscopy. This is a new and innovative diagnostic method that uses vertical scanning to provide fast, high-resolution imaging of freshly excised tissue, even using fluorescently labeled antibodies.

Drug eruptions associated with tumor therapy: Great imitators

Many studies have investigated cutaneous reactions to antitumor drugs and found them to be quite numerous. We describe drug eruptions that may be associated with different therapies by class: antimetabolite chemotherapeutics, genotoxic agents, spindle inhibitors, signal transduction inhibitors, and immunotherapies. Methotrexate is most often associated with mucocutaneous reactions, alkylating antimetabolite agents with hyperpigmentation, and platinum antimetabolite agents with type I IgE-mediated hypersensitivity reactions. Anthracycline derivatives can induce the hand-foot syndrome in patients, and bleomycin is associated with a bleomycin-induced flagellate erythema. Taxane spindle inhibitors can result in acneiform eruptions, which may also be seen with use of epidermal growth factor receptor inhibitors. Imatinib and its derivatives can cause a truncal maculopapular eruption, whereas multikinase inhibitors can produce a hand-foot-skin reaction. Vemurafenib can result in squamous cell carcinomas and photosensitivity. First-generation mammalian target of rapamycin inhibitors may cause a maculopapular eruption initially involving the face and neck. Programmed death (PD)-1-ligand and receptor inhibitors are associated with bullous pemphigoid. Ipilimumab, targeting Cytotoxic -T- Lymphocyte- associated (CTLA-4) receptors, can cause a morbilliform reaction, whereas Interleukin -2 (IL-2) analogs can create the capillary leak syndrome. Chemotherapeutic drug eruptions classically can manifest in the aforementioned ways; however, it is important to understand that they are associated with myriad cutaneous adverse effects, which may be mistaken for organic skin disease. Oncologists prescribing these medications should be familiar with the cutaneous side effects of these medications, and so they may counsel patients to be on the lookout for them.

Bullous Pemphigoid-like Skin Lesions and Overt Eosinophilia in a Patient With Melanoma Treated With Nivolumab: Case Report and Review of the Literature

The widespread use of immune checkpoint inhibitors has shed light to several unusual immune-related adverse effects of the drugs. Severe cutaneous adverse reactions are generally rare with anti-PD1 agents. We present in this paper the case of a 48-year-old patient with melanoma who developed bullous pemphigoid-like skin lesions along with fever, arthralgia and overt eosinophilia following adjuvant treatment with nivolumab. The condition was successfully treated with corticosteroids and a rechallenge with another anti-PD1 agent did not lead to recurrence of the skin lesions. We also reviewed the literature on the epidemiologic, clinical, and histopathologic characteristics of bullous pemphigoid as well as on the treatment and prognosis of this dermatologic condition in patients with melanoma or other malignancies under treatment with immune checkpoint inhibitors.

Anti-programmed cell death-1 therapy-associated bullous disorders: a systematic review of the literature

Bullous disorders are rare adverse events associated with anti-programmed cell death-1 (anti-PD1) therapy. This paper presents two new cases of bullous disorders under anti-PD1 therapy and systematically reviewed the literature to foster a better understanding of the presentation and pathogenesis of bullous disorders under anti-PD1. A systematic review of the literature was completed using MEDLINE, Embase, PubMed and LILACS databases. We identified 29 cases of bullous disorders under anti-PD1 therapy, including our two new cases. This includes 18 cases of bullous pemphigoid (BP), five cases of toxic epidermal necrolysis (TEN)/Stevens-Johnson syndrome (SJS) spectrum, one case of erythema multiforme (EM), four cases of bullous lichenoid reactions and one case of vesiculobullous eczema. In BP, blistering occurred by a median of 23 weeks after anti-PD1 therapy initiation and is often preceded by a prodrome, which lasts for a median of 9.5 weeks. Limbs and trunk were the most frequently involved body sites. Most cases (76%) achieved remission. In TEN/SJS/EM, blistering was usually preceded by a prodrome of interface dermatitis that lasted for a median of 1.5 weeks. Most cases (80%) died from either TEN/SJS or disease progression. Bullous disorders under anti-PD1 may be classified clinically as BP, SJS/TEN/EM, bullous lichenoid reactions and vesiculobullous eczema and histologically by intraepidermal splitting and subepidermal splitting. BP is usually preceded by a pruritic eruption and has a relatively good prognosis. SJS/TEN is usually preceded by a maculopapular eruption and has a very poor prognosis.